Knowledge + Practice

CCNA Eigrp Questions

75 of 92 questions · Page 1/2 · Eigrp topic · Answers revealed

Practice these questions Exam hub All questions

1

MCQeasy

What is the default EIGRP hello interval on a point-to-point serial link?

A.5 seconds

B.10 seconds

C.30 seconds

D.60 seconds

AnswerA

Correct. The default hello interval for point-to-point serial links is 5 seconds.

Why this answer

The default EIGRP hello interval on a point-to-point serial link is 5 seconds. EIGRP uses different hello intervals depending on the media type: for high-speed broadcast links (e.g., Ethernet) and point-to-point links, the default is 5 seconds; for multipoint non-broadcast links (e.g., Frame Relay), the default is 60 seconds.

Exam trap

Cisco often tests the distinction between EIGRP and OSPF hello intervals, so the trap here is that candidates confuse the 10-second OSPF default with EIGRP's 5-second default on point-to-point links.

How to eliminate wrong answers

Option B (10 seconds) is wrong because 10 seconds is the default hello interval for OSPF on broadcast and point-to-point links, not for EIGRP. Option C (30 seconds) is wrong because 30 seconds is not a standard EIGRP hello interval; it is the default hold time multiplier factor (3x hello) on some links, but not the hello timer itself. Option D (60 seconds) is wrong because 60 seconds is the default EIGRP hello interval only on low-speed multipoint non-broadcast links (e.g., Frame Relay multipoint), not on point-to-point serial links.

Practice this question →

2

MCQmedium

Consider the following configuration: router eigrp TEST network 10.0.0.0 0.255.255.255 metric weights 0 1 0 1 0 0 What is the effect of the 'metric weights' command?

A.It changes the EIGRP metric calculation to use only bandwidth and delay, which is the default behavior.

B.It changes the EIGRP metric calculation to use bandwidth, delay, and reliability.

C.It changes the EIGRP metric calculation to use only delay.

D.It disables the EIGRP metric calculation, causing all routes to have the same metric.

AnswerA

Correct. K1=1 (bandwidth) and K3=1 (delay) are used; K2, K4, K5 are zero, matching the default EIGRP metric.

Why this answer

The 'metric weights' command in EIGRP allows you to modify the K values used in the composite metric formula. The default K values are K1=1, K2=0, K3=1, K4=0, K5=0, which means only bandwidth (K1) and delay (K3) are used. The command 'metric weights 0 1 0 1 0 0' explicitly sets K1=1, K3=1, and all others to 0, which matches the default behavior and does not change the metric calculation.

Exam trap

Cisco often tests the misconception that changing K values from their defaults always alters the metric calculation, but here the specific values '0 1 0 1 0 0' exactly replicate the default K values (K1=1, K3=1), so the command has no net effect.

How to eliminate wrong answers

Option B is wrong because setting K4=0 (the fourth parameter) means reliability is not used in the metric calculation; to include reliability, K4 must be set to 1. Option C is wrong because while delay (K3) is used, bandwidth (K1) is also set to 1, so the metric uses both bandwidth and delay, not only delay. Option D is wrong because the 'metric weights' command does not disable metric calculation; it simply defines which K values are non-zero, and with K1 and K3 set to 1, the standard EIGRP composite metric is still computed.

Practice this question →

3

MCQhard

An engineer configures EIGRP on a new router in a DMVPN network. The router has a single physical interface with two subinterfaces: one for the DMVPN tunnel and one for a direct point-to-point link to a hub router. The engineer notices that EIGRP adjacencies form only on the point-to-point link, not on the DMVPN tunnel. The tunnel interface is configured with ip nhrp network-id 1 and ip nhrp nhs 10.1.1.1. What is the most likely reason?

A.The tunnel interface is not configured with the 'ip nhrp map' command for the hub router.

B.The tunnel interface is not configured with the 'ip eigrp' command under the interface configuration.

C.The DMVPN tunnel is using a different autonomous system number than the point-to-point link.

D.The tunnel interface is in a different VRF than the point-to-point link.

AnswerB

Correct. For EIGRP to form an adjacency over the tunnel interface, the interface must be included in the EIGRP process, typically with 'ip eigrp <as-number>' under the interface. Without it, EIGRP will not send or receive hello packets on that interface.

Why this answer

The most common reason for EIGRP not forming an adjacency over a tunnel interface is the absence of the 'ip eigrp' command under that interface. Without this command, EIGRP is not enabled on the tunnel, so it will not send or process Hello packets, preventing adjacency formation even if NHRP and tunnel parameters are correctly configured.

Exam trap

Cisco often tests the distinction between routing protocol configuration (e.g., 'ip eigrp') and tunnel-specific parameters (e.g., NHRP), leading candidates to incorrectly blame NHRP mapping or AS number mismatches when the real issue is the missing EIGRP enable command on the interface.

How to eliminate wrong answers

Option A is wrong because the 'ip nhrp map' command is not required for a hub router in a DMVPN phase 2 or 3 spoke configuration; the spoke uses NHRP to dynamically register with the hub, and the hub's address is already specified with 'ip nhrp nhs'. Option C is wrong because if the autonomous system numbers were different, EIGRP would still attempt to form an adjacency but would fail due to mismatched AS numbers, not fail to initiate the adjacency at all; the question states adjacencies form only on the point-to-point link, implying the tunnel interface is not even attempting to form an adjacency. Option D is wrong because a VRF mismatch would prevent routing information exchange but would not prevent the EIGRP adjacency from forming; EIGRP can form adjacencies across VRFs if configured correctly, and the issue here is that no adjacency forms at all.

Practice this question →

4

Multi-Selecthard

Which three statements about EIGRP packet types are true? (Choose three.)

Select 3 answers

A.Hello packets are sent unreliably and do not require an acknowledgment.

B.Update packets are always sent as multicast to all EIGRP neighbors.

C.Query packets are sent reliably and require a Reply from each neighbor.

D.ACK packets are unicast and are used to acknowledge reliable EIGRP packets.

E.Reply packets are sent unreliably to conserve bandwidth.

AnswersA, C, D

Correct because Hello packets are sent as best-effort (unreliable) and are not acknowledged.

Why this answer

EIGRP uses five packet types: Hello (neighbor discovery/maintenance), Update (route information), Query (ask neighbors for routes), Reply (response to Query), and ACK (acknowledgment). Hello packets are multicast to 224.0.0.10, unacknowledged, and used to form and maintain adjacencies. Update packets are sent reliably (with ACK) and can be multicast or unicast.

Query packets are multicast and require a Reply. ACK packets are unicast and are used to acknowledge reliable packets.

Practice this question →

5

MCQhard

A network engineer runs the following command on Router R1: R1# show ip eigrp topology all-links EIGRP-IPv4 Topology Table for AS(100)/ID(192.168.1.1) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.1.1.0/24, 1 successors, FD is 1310720, serno 5 via 192.168.1.2 (1310720/1310720), GigabitEthernet0/0 via 10.2.2.2 (1587200/1310720), GigabitEthernet0/1 P 10.2.2.0/24, 1 successors, FD is 1310720, serno 6 via 192.168.1.2 (1310720/1310720), GigabitEthernet0/0 via 10.2.2.2 (1587200/1310720), GigabitEthernet0/1 Based on this output, what can be concluded?

A.Both routes have a feasible successor via 10.2.2.2.

B.The route 10.1.1.0/24 has two successors.

C.The alternate path via 10.2.2.2 will be used immediately if the successor fails.

D.The router has two paths to 10.1.1.0/24, but only one is in the routing table.

AnswerD

Only the successor is installed in the routing table; the other path is not used unless the successor fails and queries are sent.

Why this answer

The output shows that for 10.1.1.0/24, the feasible distance (FD) is 1310720 and there is only one successor (the route via 192.168.1.2). The alternate path via 10.2.2.2 has a reported distance (RD) of 1310720, which equals the FD, so it does not satisfy the feasibility condition (RD < FD) and therefore is not a feasible successor. Only the successor route is installed in the routing table.

Exam trap

Cisco often tests the distinction between a successor and a feasible successor, and the trap here is that candidates assume any alternate path with a lower metric than the FD is a feasible successor, but the feasibility condition requires the reported distance to be strictly less than the feasible distance, not less than or equal.

How to eliminate wrong answers

Option A is wrong because the alternate path via 10.2.2.2 has a reported distance equal to the feasible distance, which violates the feasibility condition (RD must be strictly less than FD) and thus is not a feasible successor. Option B is wrong because the output explicitly states '1 successors' for 10.1.1.0/24, meaning there is only one successor, not two. Option C is wrong because the alternate path is not a feasible successor; if the successor fails, EIGRP must send queries and go active for that route before it can use the alternate path, so it will not be used immediately.

Practice this question →

6

MCQmedium

A router has the following configuration snippet: vrf definition RED rd 100:1 ! interface Loopback0 ip vrf forwarding RED ip address 10.0.0.1 255.255.255.255 ! router eigrp 100 address-family ipv4 unicast vrf RED autonomous-system 100 network 10.0.0.1 0.0.0.0 What is the issue with this EIGRP configuration for VRF RED?

A.The EIGRP address-family is not activated because 'no shutdown' is missing under the address-family configuration.

B.The 'network' command should use a wildcard mask of 0.0.0.255 instead of 0.0.0.0.

C.The VRF must be defined under 'router eigrp' globally before using address-family.

D.The loopback interface cannot be placed in a VRF because it is a virtual interface.

AnswerA

Correct. EIGRP address-families require 'no shutdown' to start.

Why this answer

The EIGRP address-family configuration for VRF RED is missing the 'no shutdown' command under the address-family mode. In Cisco IOS, EIGRP address-families are administratively shut down by default; without 'no shutdown', the EIGRP process for that VRF will not form adjacencies or advertise routes, even though the network command is correctly configured.

Exam trap

Cisco often tests the default administrative shutdown of EIGRP address-families, knowing that many candidates assume the process starts automatically once the network command is configured, leading them to overlook the required 'no shutdown' command.

How to eliminate wrong answers

Option B is wrong because the 'network 10.0.0.1 0.0.0.0' command uses a host-specific wildcard mask, which is perfectly valid for advertising a single /32 interface; a wildcard mask of 0.0.0.255 would be incorrect as it would attempt to match a broader subnet. Option C is wrong because VRF definitions are not required under 'router eigrp' globally; the VRF is referenced directly in the address-family configuration via the 'vrf RED' keyword, which is the correct method. Option D is wrong because loopback interfaces can absolutely be placed in a VRF; there is no restriction against virtual interfaces being assigned to a VRF, and this is a common practice for management or iBGP peering.

Practice this question →

7

Drag & Dropmedium

Drag and drop the steps of EIGRP redistribution from OSPF with metric seeding into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

When redistributing OSPF into EIGRP with metric seeding, the correct order is: First, enter EIGRP router configuration mode (A). Second, if using named mode, specify the address-family (B). Third, set the default-metric (D) before redistribution to ensure routes receive proper metric values.

Fourth, issue the 'redistribute ospf process-id' command (C). Finally, verify with 'show ip eigrp topology all-links' (E).

Practice this question →

8

MCQmedium

A network engineer runs the following command on Router R1: R1# show ip eigrp interfaces detail EIGRP-IPv4 Interfaces for AS(100) Interface: GigabitEthernet0/0 Mtu: 1500, Bandwidth: 1000000 Kbit, Delay: 100 microseconds Reliability: 255/255, Load: 1/255, Min MTU: 1500 Hello interval: 5 sec, Hold time: 15 sec Next hello in: 3 secs Passive interface: No Split horizon: Enabled Authentication: None Neighbor count: 1 Interface: GigabitEthernet0/1 Mtu: 1500, Bandwidth: 100000 Kbit, Delay: 1000 microseconds Reliability: 255/255, Load: 1/255, Min MTU: 1500 Hello interval: 5 sec, Hold time: 15 sec Next hello in: 1 secs Passive interface: No Split horizon: Enabled Authentication: None Neighbor count: 1 Based on this output, what can be concluded?

A.Both interfaces have the same metric weight for bandwidth and delay.

B.GigabitEthernet0/1 will have a higher EIGRP metric than GigabitEthernet0/0 for the same prefix.

C.Interface Gi0/1 is configured as a passive interface.

D.EIGRP authentication is enabled on both interfaces.

AnswerB

EIGRP metric uses bandwidth and delay; lower bandwidth and higher delay increase the metric.

Why this answer

EIGRP uses the composite metric formula: metric = (K1 * bandwidth + (K2 * bandwidth) / (256 - load) + K3 * delay) * (K5 / (reliability + K4)). With default K values (K1=K3=1, others=0), the metric simplifies to bandwidth + delay. Gi0/0 has bandwidth 1,000,000 Kbit and delay 100 microseconds, while Gi0/1 has bandwidth 100,000 Kbit and delay 1000 microseconds.

The lower bandwidth and higher delay on Gi0/1 result in a higher metric for the same prefix.

Exam trap

Cisco often tests the misconception that the 'show ip eigrp interfaces detail' command displays the K values or metric weights, when in fact it only shows per-interface parameters like bandwidth and delay, and the K values must be verified separately with 'show ip protocols'.

How to eliminate wrong answers

Option A is wrong because the metric weights (K values) are not shown in the output; the command only displays interface-specific parameters like bandwidth and delay, not the K values themselves. Option C is wrong because the output explicitly shows 'Passive interface: No' for Gi0/1, meaning it is not configured as a passive interface. Option D is wrong because the output shows 'Authentication: None' for both interfaces, indicating no EIGRP authentication is enabled.

Practice this question →

9

MCQmedium

A network engineer runs the following command on Router R1: R1# show ip eigrp topology EIGRP-IPv4 Topology Table for AS(100)/ID(192.168.1.1) Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - reply Status, s - sia Status P 10.1.1.0/24, 1 successors, FD is 1310720 via 192.168.1.2 (1310720/1310720), GigabitEthernet0/0 P 10.2.2.0/24, 1 successors, FD is 1310720 via 192.168.1.2 (1310720/1310720), GigabitEthernet0/0 P 10.3.3.0/24, 1 successors, FD is 1310720 via 192.168.1.2 (1310720/1310720), GigabitEthernet0/0 Based on this output, what can be concluded?

A.All routes have a feasible successor.

B.The routes are in Active state, meaning the router is querying for alternate paths.

C.Each route has exactly one successor and no feasible successor.

D.The router is using EIGRP stub routing.

AnswerC

The output shows one successor per route and the RD equals the FD, so no feasible successor.

Why this answer

The output shows each route with a code 'P' (Passive) and exactly one successor, with no feasible successor listed. In EIGRP, a feasible successor is only present if there is a backup route that satisfies the feasibility condition (reported distance < feasible distance). Since only one next-hop is shown per route and no additional entries exist, there is no feasible successor.

Option C correctly identifies this.

Exam trap

Cisco often tests the distinction between Passive and Active states in EIGRP topology table output, where candidates mistakenly think 'P' stands for 'Primary' or 'Path' instead of 'Passive', leading them to misinterpret the route state and miss the absence of feasible successors.

How to eliminate wrong answers

Option A is wrong because the output does not show any feasible successor; each route has only one successor and no backup path, so the statement 'All routes have a feasible successor' is false. Option B is wrong because the routes are in Passive state (code 'P'), not Active; Active state would indicate the router is actively querying neighbors for alternate paths, which is not the case here. Option D is wrong because the output does not indicate stub routing; EIGRP stub routing is configured with the 'eigrp stub' command and would not be evident from the topology table alone, and the routes are normal learned routes, not stub-specific behavior.

Practice this question →

10

MCQmedium

Consider the following configuration: router eigrp 100 network 10.0.0.0 0.255.255.255 passive-interface default no passive-interface GigabitEthernet0/0 Which statement is true about this EIGRP configuration?

A.EIGRP will send and receive updates only on GigabitEthernet0/0.

B.EIGRP will send updates on all interfaces except GigabitEthernet0/0.

C.EIGRP will not send any updates because the network statement is incorrect.

D.EIGRP will form adjacencies on all interfaces that have an IP address in the 10.0.0.0/8 range.

AnswerA

All interfaces are passive by default, but Gi0/0 is explicitly enabled for EIGRP updates.

Why this answer

The `passive-interface default` command sets all interfaces to passive by default, preventing EIGRP from sending or receiving hello packets (and thus updates) on them. The `no passive-interface GigabitEthernet0/0` command then overrides this default for that specific interface, allowing EIGRP to send and receive updates only on GigabitEthernet0/0. The network statement 10.0.0.0 0.255.255.255 enables EIGRP on any interface matching the 10.0.0.0/8 range, but the passive-interface logic restricts actual adjacency formation.

Exam trap

Cisco often tests the interaction between `passive-interface default` and `no passive-interface` to see if candidates understand that the default passive setting overrides all interfaces except those explicitly enabled, rather than the reverse.

How to eliminate wrong answers

Option B is wrong because the configuration uses `passive-interface default` followed by `no passive-interface GigabitEthernet0/0`, which makes only GigabitEthernet0/0 active for EIGRP updates, not all interfaces except GigabitEthernet0/0. Option C is wrong because the network statement `10.0.0.0 0.255.255.255` is a valid wildcard mask that matches the 10.0.0.0/8 prefix, and EIGRP will enable on any interface with an IP in that range; the passive-interface logic does not invalidate the network statement. Option D is wrong because although the network statement enables EIGRP on all interfaces in the 10.0.0.0/8 range, the `passive-interface default` command suppresses hello packets and adjacency formation on all interfaces except GigabitEthernet0/0, so adjacencies will not form on other interfaces.

Practice this question →

11

MCQeasy

A network engineer is troubleshooting an EIGRP issue where two routers, R1 and R2, are directly connected. Neither router shows an EIGRP adjacency with the other. The engineer checks the interface configurations and finds that R1 has 'ip authentication mode eigrp 1 md5' and 'ip authentication key-chain eigrp 1 MYKEY' configured, while R2 has no authentication configured. What is the most likely cause?

A.R1 has authentication configured, but R2 does not, so R1 will reject R2's hello packets, and no adjacency forms.

B.R2 will automatically learn the authentication key from R1 and form an adjacency.

C.R1 will form an adjacency with R2 because authentication is optional.

D.The adjacency will form but only for routes that are not authenticated.

AnswerA

Correct. EIGRP authentication requires both sides to have matching authentication. Since R2 does not have authentication, R1 will discard R2's hello packets, preventing adjacency.

Why this answer

R1 has authentication configured, so it includes MD5 authentication data in its hello packets and expects authenticated hellos from neighbors. R2 does not have authentication configured, so it sends unauthenticated hellos. R1 drops R2's unauthenticated hellos, and R2 does not process R1's authenticated hellos (or the mismatch prevents a bidirectional relationship), resulting in no EIGRP adjacency being formed on either router.

Exam trap

Cisco often tests the misconception that authentication is optional or that a router can learn keys dynamically; the trap here is assuming that an adjacency can form unidirectionally when authentication is mismatched, when in fact EIGRP requires matching authentication parameters for bidirectional neighbor discovery.

How to eliminate wrong answers

Option B is wrong because EIGRP does not support automatic key learning; authentication keys must be manually configured on both routers. Option C is wrong because when authentication is enabled on one side, it is not optional—the receiving router will drop unauthenticated or mismatched hello packets, preventing adjacency formation. Option D is wrong because EIGRP authentication applies to all EIGRP packets (including hellos and updates); there is no mechanism to form an adjacency for only a subset of routes.

Practice this question →

12

Matchingmedium

Drag and drop each EIGRP metric component on the left to its matching variable on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

Bandwidth

Load

Delay

Reliability

Why these pairings

K1 corresponds to bandwidth, K2 to load, K3 to delay, and K4 to reliability. K5 is not directly assigned to a single metric component; it is a multiplier used with reliability in the metric formula. MTU is not a K variable; it is only used in the feasibility condition.

Exam trap

A common mistake is to assign MTU to K5, but MTU is not a component of the EIGRP metric formula.

Practice this question →

13

MCQeasy

What is the maximum hop count for EIGRP?

A.15

B.100

C.255

D.Unlimited

AnswerB

The default maximum hop count for EIGRP is 100.

Why this answer

EIGRP uses a metric based on bandwidth and delay, but it also has a hop count limit. The default maximum hop count is 100, but it can be configured up to 255.

Practice this question →

14

MCQhard

A network engineer runs the following command on Router R5: R5# show ip route vrf CUSTOMER-A Routing Table: CUSTOMER-A Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is 10.1.1.1 to network 0.0.0.0 10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks C 10.1.1.0/24 is directly connected, GigabitEthernet0/0 B 10.2.2.0/24 [20/0] via 10.1.1.1, 00:10:20 Based on this output, what can be concluded?

A.The VRF has no routes and is not functional.

B.The route 10.2.2.0/24 is learned via OSPF.

C.The VRF has a default route pointing to 10.1.1.1.

D.The BGP route is sourced from an internal BGP peer.

AnswerC

The gateway of last resort is 10.1.1.1, meaning a default route exists via that next hop.

Why this answer

The output shows a VRF routing table with a gateway of last resort set to 10.1.1.1 for network 0.0.0.0, which is a default route. This indicates that the VRF has a default route pointing to 10.1.1.1, making option C correct. The presence of a connected route and a BGP-learned route further confirms the VRF is functional.

Exam trap

Cisco often tests the distinction between eBGP and iBGP by using administrative distance values; the trap here is that candidates may assume any BGP route is from an internal peer without checking the AD value, which for eBGP is 20 and for iBGP is 200.

How to eliminate wrong answers

Option A is wrong because the VRF has both a connected route (10.1.1.0/24) and a BGP-learned route (10.2.2.0/24), so it is functional. Option B is wrong because the route 10.2.2.0/24 is marked with 'B' in the routing table, which indicates it is learned via BGP, not OSPF. Option D is wrong because the BGP route shows an administrative distance of 20 and a metric of 0, which are typical for eBGP (external BGP) routes, not iBGP (internal BGP) routes; iBGP routes typically have an administrative distance of 200.

Practice this question →

15

MCQmedium

A network engineer is troubleshooting an EIGRP issue in a large enterprise network. Two routers, R1 and R2, are connected via a T1 link. R1 is learning a route to 10.0.0.0/8 from R2 with a metric of 28160, but the same route is also learned from another neighbor with a metric of 26880. The engineer notices that the route from R2 is not being installed in the routing table. What is the most likely cause?

A.The route from R2 is a feasible successor, so it is not installed in the routing table.

B.EIGRP is using unequal-cost load balancing, so the higher metric route is not used.

C.The route with metric 28160 is not installed because EIGRP selects the route with the lowest metric.

D.The route from R2 is a summary route, so it is not installed in the routing table.

AnswerC

Correct. EIGRP installs only the route with the best (lowest) metric in the routing table. Since 26880 is lower than 28160, the route from R2 is not installed.

Why this answer

C is correct because EIGRP installs only the route with the best (lowest) metric into the routing table. The route from R2 has a metric of 28160, while the other neighbor advertises the same route with a metric of 26880. Since 26880 is lower, R1 selects that route as the successor and does not install the higher-metric route from R2.

Exam trap

Cisco often tests the misconception that all learned EIGRP routes are installed in the routing table, but in reality only the successor (lowest metric) is installed unless unequal-cost load balancing is explicitly configured.

How to eliminate wrong answers

Option A is wrong because a feasible successor is a backup route that is kept in the topology table but not installed in the routing table unless the successor fails; however, the question states that the route from R2 is not installed, but it is not necessarily a feasible successor—it could simply be a non-successor route that does not meet the feasibility condition. Option B is wrong because unequal-cost load balancing (variance) is optional and, even if enabled, would only load-balance across routes that meet the variance multiplier; the route with metric 28160 would still not be installed if it is not selected as a successor or feasible successor under the variance condition. Option D is wrong because there is no indication that the route from R2 is a summary route; summary routes are typically installed with a lower administrative distance or as a local route, and the metric difference alone does not imply summarization.

Practice this question →

16

Multi-Selectmedium

Which two statements about EIGRP route summarization are true? (Choose two.)

Select 2 answers

A.Manual summarization can be configured on a per-interface basis using the ip summary-address eigrp command.

B.Automatic summarization is enabled by default in EIGRP for IPv4.

C.A manually configured summary route in EIGRP has an administrative distance of 5.

D.Manual summarization causes the router to advertise all specific routes in addition to the summary.

E.EIGRP for IPv6 does not support manual summarization.

AnswersA, C

Correct because the command 'ip summary-address eigrp <as> <prefix> <mask>' is used to configure manual summarization on an interface.

Why this answer

EIGRP supports manual summarization on any interface, which creates a summary route with an administrative distance of 5 by default. Automatic summarization at classful boundaries is disabled by default in modern IOS versions. Manual summarization can be configured per interface and suppresses more specific routes from being advertised out that interface.

The summary route is installed in the routing table as a local route.

Practice this question →

17

MCQeasy

What is the maximum hop count for EIGRP?

A.255

B.100

C.15

D.224

AnswerA

Correct. EIGRP has a maximum hop count of 255.

Why this answer

EIGRP uses a maximum hop count of 255, which is the default and hard limit built into the protocol. This value is stored in the TTL field of the EIGRP packet header, and once a route exceeds 255 hops, it is considered unreachable. This high limit allows EIGRP to scale in large enterprise networks without the restrictive hop count constraints of distance-vector protocols like RIP.

Exam trap

Cisco often tests the distinction between EIGRP's hop count limit of 255 and RIP's hop count limit of 15, tempting candidates who confuse these two distance-vector protocols.

How to eliminate wrong answers

Option B is wrong because 100 is not a valid hop count limit for any Cisco routing protocol; it may be confused with the administrative distance of OSPF or the metric weight components. Option C is wrong because 15 is the maximum hop count for RIP (Routing Information Protocol), not EIGRP; this is a classic confusion between distance-vector protocols. Option D is wrong because 224 is the multicast address (224.0.0.10) used by EIGRP for hello packets, not a hop count limit.

Practice this question →

18

MCQeasy

What is the maximum hop count for EIGRP?

A.255

B.15

C.128

D.Unlimited

AnswerA

EIGRP uses a 1-byte hop count field, allowing a maximum of 255 hops.

Why this answer

EIGRP uses a maximum hop count of 255 to prevent routing loops, which is a hard limit enforced by the protocol. This value is configurable via the 'metric maximum-hops' command under the EIGRP process, but the absolute maximum is 255. Unlike distance-vector protocols like RIP, EIGRP is an advanced distance-vector protocol that uses the Diffusing Update Algorithm (DUAL) for loop avoidance, but the hop count serves as a final safety mechanism.

Exam trap

Cisco often tests the distinction between the default hop count (100) and the maximum hop count (255), leading candidates to mistakenly select 128 or 15 due to confusion with other protocols or default values.

How to eliminate wrong answers

Option B is wrong because 15 is the maximum hop count for RIP (Routing Information Protocol), not EIGRP; this is a common confusion between distance-vector protocols. Option C is wrong because 128 is the default hop count for EIGRP, not the maximum; the default is 100, but it can be increased up to 255. Option D is wrong because EIGRP does have a finite maximum hop count of 255; it is not unlimited, as the protocol must have a loop-prevention boundary.

Practice this question →

19

Drag & Dropmedium

Drag and drop the steps of EIGRP authentication using MD5 key-chain into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

The correct order for configuring EIGRP MD5 authentication with a key chain is: first, create a key chain using the 'key chain' command. Next, configure a key number and key-string under the key chain. Then, enter interface configuration mode for the interface on which EIGRP is enabled.

After that, issue the command 'ip authentication mode eigrp md5' to set the authentication mode. Finally, issue the command 'ip authentication key-chain eigrp <name>' to apply the key chain to the interface.

Practice this question →

20

MCQmedium

A network engineer is configuring EIGRP on a router that connects to multiple remote sites via Frame Relay. The engineer wants to ensure that EIGRP does not form adjacencies over the Frame Relay interfaces to reduce overhead, but still wants to advertise the connected networks. The engineer applies the 'passive-interface' command to the Frame Relay interfaces. However, the remote sites stop receiving the routes. What is the most likely reason?

A.The 'passive-interface' command also prevents EIGRP from sending routing updates on that interface.

B.The 'passive-interface' command only affects hello packets, not updates, but the remote sites are not configured correctly.

C.The engineer should use the 'neighbor' command under the EIGRP process to specify the remote routers.

D.The remote sites are using a different EIGRP autonomous system number.

AnswerA

Correct. The passive-interface command suppresses both hello packets and routing updates. Therefore, the remote sites do not receive the routes.

Why this answer

The 'passive-interface' command in EIGRP prevents both hello and routing updates from being sent on the specified interface. Since EIGRP relies on hello packets to form and maintain neighbor adjacencies, applying this command to the Frame Relay interfaces stops adjacency formation. Without an adjacency, no routes are exchanged, so the remote sites stop receiving the advertised networks.

Exam trap

Cisco often tests the misconception that 'passive-interface' only affects routing updates but not hello packets, leading candidates to think adjacencies can still form and routes can be received.

How to eliminate wrong answers

Option A is correct because the 'passive-interface' command suppresses both hello and routing updates, breaking adjacency. Option B is wrong because the 'passive-interface' command does affect updates, not just hello packets; it suppresses all EIGRP traffic on the interface, including updates. Option C is wrong because the 'neighbor' command is used for EIGRP over non-broadcast multi-access (NBMA) networks like Frame Relay to define static neighbors, but it does not override the 'passive-interface' command; the interface would still be passive and no packets would be sent.

Option D is wrong because if the remote sites used a different autonomous system number, they would never form adjacencies regardless of the passive-interface command; the question states they were receiving routes before the change, so the AS numbers must match.

Practice this question →

21

MCQhard

A network engineer is configuring a DMVPN Phase 3 deployment with EIGRP as the routing protocol. The hub router has multiple spoke routers behind a single physical interface. The engineer notices that spoke-to-spoke traffic is being forwarded through the hub instead of directly. The spoke routers have the correct NHRP and mGRE configuration. What is the most likely cause of this issue?

A.The hub router is configured with 'no ip next-hop-self eigrp' under the tunnel interface.

B.The hub router is configured with 'ip next-hop-self eigrp' under the tunnel interface.

C.The spoke routers have 'ip nhrp shortcut' configured but the hub does not have 'ip nhrp redirect'.

D.The spoke routers are using static NHRP mappings to the hub only, without dynamic NHRP registration.

AnswerB

Correct. With next-hop-self enabled, the hub advertises routes with its own IP as the next hop, preventing spokes from learning the remote spoke's tunnel IP and thus no direct tunnel is built.

Why this answer

In DMVPN Phase 3, spoke-to-spoke direct communication relies on the hub sending an NHRP Redirect to inform the source spoke of a better path. However, if the hub has 'ip next-hop-self eigrp' configured under the tunnel interface, EIGRP updates sent from the hub will set the next-hop to the hub's own tunnel IP address. This causes the spoke routers to install routes with the hub as the next-hop, preventing them from triggering an NHRP resolution for a direct spoke-to-spoke tunnel.

The correct behavior for Phase 3 is to use 'no ip next-hop-self eigrp' so that the original spoke's next-hop is preserved, allowing spokes to resolve the destination via NHRP.

Exam trap

Cisco often tests the distinction between Phase 2 and Phase 3 DMVPN behavior, where candidates mistakenly think 'ip next-hop-self' is always required for EIGRP over DMVPN, but in Phase 3 it must be disabled to allow NHRP shortcut resolution.

How to eliminate wrong answers

Option A is wrong because 'no ip next-hop-self eigrp' is actually the correct configuration for DMVPN Phase 3; it preserves the original next-hop in EIGRP updates, enabling spoke-to-spoke direct traffic. Option C is wrong because 'ip nhrp shortcut' on spokes and 'ip nhrp redirect' on the hub are required for Phase 3 operation; if both are missing, traffic would not be redirected, but the question states the spokes have correct NHRP configuration, implying 'ip nhrp shortcut' is present, and the hub's missing redirect would cause a different symptom (no NHRP Redirect messages). Option D is wrong because static NHRP mappings to the hub only are typical in Phase 2 and Phase 3; dynamic registration is used for the hub to learn spoke addresses, but static mappings do not prevent spoke-to-spoke traffic if the routing protocol correctly preserves next-hop information.

Practice this question →

22

Drag & Dropmedium

Drag and drop the steps of EIGRP stub configuration for hub-and-spoke into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

The correct order ensures that the spoke router first enters EIGRP configuration, then configures the stub feature, optionally restricts stub types, and finally applies the configuration. The hub router does not need stub configuration.

Practice this question →

23

MCQmedium

A network engineer runs the following command on Router R3: R3# show ip route ospf Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP a - application route + - replicated route, % - next hop override Gateway of last resort is not set 10.0.0.0/8 is variably subnetted, 5 subnets, 3 masks O IA 10.1.1.0/24 [110/20] via 192.168.1.1, 00:12:34, GigabitEthernet0/0 O 10.2.2.0/24 [110/10] via 192.168.1.2, 00:15:22, GigabitEthernet0/0 O E2 10.3.3.0/24 [110/20] via 192.168.1.3, 00:08:11, GigabitEthernet0/0 Based on this output, what can be concluded?

A.The route to 10.3.3.0/24 is an external route redistributed into OSPF.

B.The route to 10.1.1.0/24 is in the same OSPF area as R3.

C.The metric for 10.3.3.0/24 includes the internal cost to the ASBR.

D.R3 is an ASBR.

AnswerA

O E2 indicates an OSPF external route of type 2, typically redistributed from another routing protocol.

Why this answer

The route to 10.3.3.0/24 is marked as 'O E2' in the output, which stands for OSPF external type 2. This indicates that the route was redistributed into OSPF from another routing protocol or a different OSPF process, making it an external route. The 'E2' designation confirms it is an external route with a fixed metric that does not include the internal cost to the ASBR.

Exam trap

Cisco often tests the difference between OSPF external type 1 (E1) and type 2 (E2) routes, specifically that E2 routes do not include the internal cost to the ASBR, which is a common misconception that leads candidates to incorrectly select option C.

How to eliminate wrong answers

Option B is wrong because the route to 10.1.1.0/24 is marked as 'O IA' (OSPF inter-area), which means it originates from a different OSPF area than R3, not the same area. Option C is wrong because for an OSPF external type 2 (E2) route, the metric shown (20) is the external metric only and does not include the internal cost to the ASBR; that behavior is specific to external type 1 (E1) routes. Option D is wrong because R3 is simply receiving these OSPF routes; there is no indication in the output that R3 is redistributing routes into OSPF, which would be required for it to be an ASBR.

Practice this question →

24

MCQmedium

Given the following EIGRP configuration: router eigrp 100 network 10.0.0.0 0.255.255.255 metric weights 0 1 1 1 0 0 ! What is the effect of the 'metric weights' command?

A.It sets the EIGRP metric to use bandwidth, load, and delay, ignoring reliability and MTU.

B.It disables EIGRP metric calculation and uses a fixed metric of 1.

C.It sets the EIGRP metric to use only bandwidth and delay, ignoring load, reliability, and MTU.

D.It configures EIGRP to use the default K values (1,0,1,0,0).

AnswerA

Correct. K1=1 (bandwidth), K2=1 (load), K3=1 (delay), K4=0, K5=0.

Why this answer

The 'metric weights' command in EIGRP allows you to modify the K values used in the composite metric calculation. The syntax is 'metric weights tos k1 k2 k3 k4 k5'. Here, the values are 0 1 1 1 0 0, meaning k1 (bandwidth) = 1, k2 (load) = 1, k3 (delay) = 1, k4 (reliability) = 0, k5 (MTU) = 0.

This results in the metric using bandwidth, load, and delay, while ignoring reliability and MTU. Option A correctly describes this effect.

Exam trap

Cisco often tests the exact mapping of the 'metric weights' command arguments to K values, and the trap here is that candidates confuse the order or assume that a value of 0 disables the entire metric calculation rather than just that specific component.

How to eliminate wrong answers

Option B is wrong because the 'metric weights' command does not disable metric calculation or set a fixed metric; it customizes the K values used in the composite metric formula. Option C is wrong because it states that only bandwidth and delay are used, but the configuration includes k2=1, which includes load in the calculation. Option D is wrong because the default K values are 1,0,1,0,0 (k1=1, k2=0, k3=1, k4=0, k5=0), but the given command sets k2=1, which deviates from the default.

Practice this question →

25

Multi-Selecthard

Which three statements about EIGRP stub routing are true? (Choose three.)

Select 3 answers

A.A stub router does not send Query packets to its neighbors.

B.A hub router will send queries to a stub router when a route is lost.

C.The 'eigrp stub' command can be configured with the 'connected' keyword to advertise only connected routes.

D.Stub routing is used to reduce the size of the routing table on the hub router.

E.A stub router can be configured as 'receive-only' to not advertise any routes.

AnswersA, C, E

Correct because stub routers are not allowed to originate queries; they rely on the hub for routing information.

Why this answer

EIGRP stub routing is used to limit the query scope and improve convergence. A stub router is typically a spoke in a hub-and-spoke topology. It advertises its directly connected and summary routes to the hub, but does not query its neighbors.

The hub router does not send queries to the stub router. The stub router can be configured with different options: connected, static, summary, receive-only, or redistributed. The 'eigrp stub' command enables this feature.

Practice this question →

26

Multi-Selecthard

Which three statements about EIGRP named mode configuration are true? (Choose three.)

Select 3 answers

A.Named mode uses the 'router eigrp <name>' command to enter configuration mode.

B.In named mode, the network statement is replaced by the 'af-interface' configuration under the address family.

C.Named mode supports both IPv4 and IPv6 address families within the same EIGRP process.

D.The 'address-family ipv4' command is used to enter IPv4 configuration under named mode.

E.Named mode requires the 'no shutdown' command under the address family to enable EIGRP.

AnswersA, C, D

Correct because named mode starts with 'router eigrp <name>', where <name> is a case-sensitive tag.

Why this answer

EIGRP named mode uses a hierarchical configuration under a single router process, supporting address families (IPv4, IPv6) and VRFs. It simplifies configuration and allows per-interface settings.

Practice this question →

27

MCQeasy

What is the maximum hop count for EIGRP?

A.255

B.15

C.224

D.Unlimited

AnswerA

EIGRP's maximum hop count is 255, inherited from IGRP.

Why this answer

EIGRP uses a maximum hop count of 255 to prevent routing loops, as defined in RFC 7868. This is a hard-coded limit in the protocol, and routes with a hop count exceeding 255 are considered unreachable.

Exam trap

Cisco often tests the EIGRP hop count limit to confuse candidates who associate hop counts with RIP (15) or confuse the value with the EIGRP multicast address (224.0.0.10).

How to eliminate wrong answers

Option B is wrong because 15 is the maximum hop count for RIP (Routing Information Protocol), not EIGRP. Option C is wrong because 224 is the multicast address (224.0.0.10) used by EIGRP for hello packets, not a hop count limit. Option D is wrong because EIGRP does have a finite hop count limit of 255, not an unlimited value, to ensure loop prevention and route convergence.

Practice this question →

28

MCQmedium

A network engineer is designing an EIGRP network with multiple routers. The network has a core layer where all routers are fully meshed. The engineer wants to ensure that if a link fails, EIGRP converges quickly without relying on route redistribution or static routes. The engineer configures EIGRP with default timers. However, during a failure simulation, convergence takes over 15 seconds. What is the most likely reason?

A.EIGRP is using passive interfaces on the core routers, preventing rapid updates.

B.The failed link was the only feasible successor for the affected routes, causing EIGRP to go into active state and query neighbors.

C.EIGRP hold timers are set to 180 seconds by default, causing slow detection.

D.The engineer configured 'eigrp stub' on the core routers, which prevents query propagation.

AnswerB

Correct. When the only feasible successor fails, EIGRP transitions to active state and sends queries to all neighbors. The time to receive all replies can exceed 15 seconds, especially in large networks.

Why this answer

When the only feasible successor (FS) for a route fails, EIGRP cannot perform a local recomputation and must transition the route to the active state. It then sends query packets to all neighbors to find an alternative path, which introduces significant delay due to the need to wait for replies from every neighbor in a fully meshed core. With default timers, this query/reply process can easily exceed 15 seconds, especially if any neighbor is slow to respond.

Exam trap

Cisco often tests the misconception that EIGRP convergence is always fast due to its DUAL algorithm, but the trap here is that without a feasible successor, the active query process can cause significant delays, especially in a fully meshed network.

How to eliminate wrong answers

Option A is wrong because passive interfaces suppress the sending of EIGRP hellos and updates, which would prevent neighbor formation entirely, not just slow convergence; the scenario implies neighbors are established. Option C is wrong because the default EIGRP hold timer is 15 seconds (not 180 seconds), and even if it were longer, the failure detection delay alone would not account for a 15-second convergence time when the primary issue is query propagation. Option D is wrong because configuring 'eigrp stub' on core routers would actually speed convergence by preventing query propagation, not slow it; stubs do not propagate queries, so they reduce the active-state delay.

Practice this question →

29

Drag & Dropmedium

Drag and drop the steps of EIGRP named mode configuration steps into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

EIGRP named mode uses an address-family configuration. First, create the named EIGRP instance, then enter address-family IPv4, configure the network, optionally adjust timers, and finally verify the configuration.

Practice this question →

30

Drag & Dropmedium

Drag and drop the steps of OSPF redistribution from EIGRP with metric conversion into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

First, identify the EIGRP routes to redistribute into OSPF. Then, configure the OSPF redistribution command under the OSPF process, specifying the EIGRP AS number. Since OSPF requires a metric for redistributed routes, set the OSPF metric type (E1 or E2) and seed metric.

Optionally, use a route map to filter or modify specific routes. Finally, verify that the redistributed routes appear in the OSPF database and routing table.

Practice this question →

31

MCQmedium

A network engineer is designing an EIGRP network with multiple routers in a hub-and-spoke topology. The engineer wants to ensure that the spoke routers do not become transit routers for traffic between other spokes. The engineer configures 'eigrp stub' on the spoke routers. However, after configuration, the spoke routers stop learning some routes from the hub. What is the most likely reason?

A.The spoke routers are configured with 'eigrp stub receive-only', which prevents them from advertising any routes, so the hub does not have routes to the spoke's networks.

B.The 'eigrp stub' command prevents the spoke from learning routes from the hub.

C.The hub router is also configured as stub, which prevents route propagation.

D.The spoke routers have a different EIGRP autonomous system number than the hub.

AnswerA

Correct. The 'receive-only' keyword prevents the spoke from advertising any routes, including its connected networks. The hub then cannot reach the spoke's networks, and the spoke may not learn routes that depend on those advertisements.

Why this answer

The 'eigrp stub receive-only' command configures the spoke router to only receive routes and not advertise any of its own networks. This causes the hub router to lack routes to the spoke's directly connected or summarized networks, breaking reachability from the hub to the spoke. The correct answer is A because this specific stub mode prevents the spoke from advertising any routes, which is the most likely reason the spoke stops learning some routes from the hub (since the hub may not have a route back to the spoke's networks).

Exam trap

Cisco often tests the misconception that 'eigrp stub' prevents a router from learning routes, when in fact it only restricts the routes the router advertises, and the 'receive-only' keyword is the specific variant that stops all advertisements, causing the hub to lack routes to the spoke's networks.

How to eliminate wrong answers

Option A is correct as explained. Option B is wrong because the 'eigrp stub' command (without 'receive-only') actually allows the spoke to learn routes from the hub; it only restricts the spoke from acting as a transit router by limiting the routes it advertises (e.g., connected, summary). Option C is wrong because configuring the hub as a stub would prevent the hub from learning routes from spokes, but the question states the spoke routers stop learning routes from the hub, which is not caused by the hub being a stub.

Option D is wrong because if the spoke and hub had different EIGRP autonomous system numbers, they would not form an adjacency at all, and the spoke would not learn any routes from the hub—this is a fundamental configuration mismatch, not a subtle effect of the stub command.

Practice this question →

32

MCQmedium

A network engineer is troubleshooting a routing loop in an EIGRP network. Which mechanism is designed to prevent routing loops by causing a router to reject routes that are learned from a neighbor that is not the successor?

A.Split horizon

B.Route poisoning

C.Hold-down timers

D.Feasibility condition

AnswerD

The feasibility condition ensures loop-free paths by verifying that the neighbor's reported distance is lower than the feasible distance.

Why this answer

The feasibility condition is a loop-prevention mechanism unique to EIGRP. It ensures that a router only accepts a route from a neighbor if that neighbor's reported distance (RD) to the destination is less than the router's own feasible distance (FD). This guarantees that the path through that neighbor is loop-free, effectively rejecting routes learned from any neighbor that is not the successor.

Exam trap

Cisco often tests the distinction between EIGRP's feasibility condition and other distance-vector loop-prevention mechanisms like split horizon or hold-down timers, expecting candidates to confuse these concepts because they all prevent loops but operate at different stages of the routing process.

How to eliminate wrong answers

Option A is wrong because split horizon prevents loops by not advertising a route back out the interface from which it was learned, but it does not evaluate whether the neighbor is the successor. Option B is wrong because route poisoning (setting the metric to infinity) is used to signal a failed route, not to reject routes from non-successor neighbors. Option C is wrong because hold-down timers are used in distance-vector protocols like RIP to suppress updates after a metric change, but EIGRP does not use hold-down timers; it relies on the Diffusing Update Algorithm (DUAL) and the feasibility condition for loop prevention.

Practice this question →

33

MCQeasy

What is the maximum hop count for EIGRP?

A.100

B.15

C.255

D.16

AnswerA

EIGRP’s default maximum hop count is 100, which satisfies the question’s constraint by defining the protocol’s loop-prevention boundary. Unlike RIP’s 15-hop limit, EIGRP uses a feasible successor mechanism and Diffusing Update Algorithm (DUAL) to maintain loop-free paths, but still enforces a hard hop-count ceiling of 100 to prevent indefinite routing loops in large topologies.

Why this answer

EIGRP uses a maximum hop count of 100 by default to prevent routing loops. This is a hard limit; if a route's hop count exceeds 100, EIGRP considers it unreachable. This value is configurable via the 'metric maximum-hops' command under the EIGRP process.

Exam trap

Cisco often tests the EIGRP hop count limit of 100 to trap candidates who confuse it with RIP's 15-hop limit or OSPF's 255-hop limit, especially when the question omits the protocol name in the stem.

How to eliminate wrong answers

Option B (15) is wrong because 15 is the maximum hop count for RIP, not EIGRP; this is a common confusion between distance-vector protocols. Option C (255) is wrong because 255 is the maximum hop count for OSPF (via the 'max-metric' LSA) or the TTL field in IP packets, but EIGRP defaults to 100. Option D (16) is wrong because 16 is the 'infinity' metric in RIP (indicating an unreachable route), not a hop count limit for EIGRP.

Practice this question →

34

Drag & Drophard

Drag and drop the steps of OSPF redistribution from EIGRP with metric conversion into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

Redistribution requires enabling redistribution, setting a seed metric (or using default-metric), optionally matching routes, and then verifying. The order ensures routes are properly injected.

Practice this question →

35

MCQmedium

Given the following configuration: router eigrp TEST network 10.0.0.0 0.255.255.255 network 192.168.1.0 ! interface GigabitEthernet0/0 ip address 10.1.1.1 255.255.255.0 ip summary-address eigrp TEST 10.0.0.0 255.0.0.0 5 What is the effect of the ip summary-address command?

A.It creates a summary route 10.0.0.0/8 with a metric of 5, advertised out GigabitEthernet0/0.

B.It creates a summary route 10.0.0.0/8 with a metric of 5, but only for the EIGRP process named TEST.

C.It creates a summary route 10.0.0.0/8 with a hop count of 5.

D.The command is invalid because the summary address must match the network statement exactly.

AnswerA

The summary address is 10.0.0.0/8, and the value 5 is the administrative distance for the summary route.

Why this answer

The `ip summary-address eigrp TEST 10.0.0.0 255.0.0.0 5` command creates a summary route of 10.0.0.0/8 with an administrative distance of 5, which is advertised out of GigabitEthernet0/0. The EIGRP process name TEST matches the router eigrp configuration, and the summary is generated regardless of the network statements, as long as the router has a more specific route within the summarized range.

Exam trap

Cisco often tests the misconception that the number after the summary address is a metric or hop count, when in fact it is the administrative distance for the summary route.

How to eliminate wrong answers

Option B is wrong because the summary route is advertised out of the specific interface (GigabitEthernet0/0), not for the entire EIGRP process; the process name only identifies which EIGRP instance the summary belongs to. Option C is wrong because the number 5 in the command sets the administrative distance for the summary route, not a hop count or metric; EIGRP uses metric (composite) values, not hop counts. Option D is wrong because the summary address does not need to match a network statement exactly; the `ip summary-address` command can summarize any range that includes subnets learned via EIGRP, even if the network statement is broader or different.

Practice this question →

36

MCQmedium

Consider the following EIGRP configuration on a Cisco IOS router: router eigrp 100 network 10.0.0.0 passive-interface default no passive-interface GigabitEthernet0/1 What is the effect of this configuration?

A.All interfaces except GigabitEthernet0/1 are passive and will not form EIGRP adjacencies.

B.EIGRP hellos are sent on all interfaces, but GigabitEthernet0/1 is prevented from forming adjacencies.

C.Only the network 10.0.0.0 is advertised, and all interfaces are passive.

D.EIGRP will only form adjacencies on interfaces with an IP address in the 10.0.0.0/8 range.

AnswerA

Correct. The default passive setting applies to all interfaces, and the exception is made only for GigabitEthernet0/1.

Why this answer

The 'passive-interface default' command sets all interfaces to passive by default, preventing them from sending EIGRP hellos and forming adjacencies. The 'no passive-interface GigabitEthernet0/1' command then overrides this default for that specific interface, allowing it to send hellos and form adjacencies. Therefore, only GigabitEthernet0/1 is active for EIGRP neighbor discovery, while all other interfaces remain passive.

Exam trap

Cisco often tests the interaction between 'passive-interface default' and 'no passive-interface' to see if candidates understand that the default command makes all interfaces passive, and the 'no' form selectively activates only the specified interface, rather than the reverse.

How to eliminate wrong answers

Option B is wrong because it reverses the logic: 'passive-interface default' prevents hellos on all interfaces by default, not sends them, and 'no passive-interface' enables hellos on the specified interface, not prevents them. Option C is wrong because the 'network 10.0.0.0' command enables EIGRP on any interface whose IP address falls within the 10.0.0.0/8 range, but the passive-interface configuration still controls whether hellos are sent and adjacencies formed; the configuration does not make all interfaces passive—only the default passive setting does, which is overridden for GigabitEthernet0/1. Option D is wrong because the 'network 10.0.0.0' command does not restrict adjacency formation to only 10.0.0.0/8 interfaces; it enables EIGRP on those interfaces, but the passive-interface default command would still prevent adjacencies on all interfaces except GigabitEthernet0/1, regardless of their IP address range.

Practice this question →

37

MCQmedium

A network engineer is troubleshooting an EIGRP adjacency issue between two routers. The engineer verifies that both routers have the same K-values and autonomous system number. However, the adjacency does not form. Which configuration issue is most likely the cause?

A.Authentication is configured on one router but not on the other.

B.The network statement uses an incorrect subnet mask.

C.One router has a loopback interface that is not advertised.

D.The hello and hold timers do not match.

AnswerA

Mismatched authentication prevents EIGRP adjacency.

Why this answer

In EIGRP, authentication (MD5 or SHA) must be configured identically on both peers. If one router has authentication enabled and the other does not, the routers will reject each other's hello packets, preventing adjacency formation even if K-values and AS numbers match. This is a common misconfiguration that breaks neighbor relationships silently.

Exam trap

Cisco often tests the misconception that EIGRP requires matching hello and hold timers (like OSPF), but EIGRP is more tolerant; the real adjacency blocker is authentication mismatch, which is frequently overlooked when K-values and AS numbers are correct.

How to eliminate wrong answers

Option B is wrong because the network statement in EIGRP uses a wildcard mask, not a subnet mask; an incorrect subnet mask in the network statement would affect which interfaces participate in EIGRP but would not prevent adjacency if both routers have matching interfaces and AS numbers. Option C is wrong because a loopback interface that is not advertised does not affect EIGRP adjacency; adjacency forms on directly connected interfaces, and a non-advertised loopback has no impact on hello packet exchange. Option D is wrong because EIGRP does not require hello and hold timers to match; EIGRP uses a graceful restart mechanism where mismatched timers still allow adjacency (though hold time must be greater than hello interval to avoid flapping).

Practice this question →

38

MCQmedium

Examine the following EIGRP configuration for route summarization: interface GigabitEthernet0/0 ip summary-address eigrp 100 192.168.0.0 255.255.252.0 What is the effect of this command?

A.EIGRP will advertise the 192.168.0.0/22 summary route out of GigabitEthernet0/0 and create a discard route.

B.EIGRP will only accept routes within the 192.168.0.0/22 range on this interface.

C.The summary route will have a metric equal to the best metric among the component routes.

D.This command will cause EIGRP to automatically summarize routes to their classful boundaries.

AnswerA

Correct. The summary-address command creates a summary route and a corresponding discard route.

Why this answer

The `ip summary-address eigrp` command creates a summary route (192.168.0.0/22) that EIGRP advertises out of the specified interface, and it automatically installs a discard (null0) route to prevent routing loops when the summary is advertised but some component routes may not be present in the routing table.

Exam trap

Cisco often tests the misconception that `ip summary-address eigrp` filters incoming routes or that it sets the summary metric to the highest metric, when in fact it creates a discard route and uses the minimum metric from component routes.

How to eliminate wrong answers

Option B is wrong because the command does not filter incoming routes; it only summarizes routes being advertised outbound. Option C is wrong because the summary route's metric is set to the minimum metric among the component routes, not the best (which could be interpreted as highest or best path). Option D is wrong because this command configures manual summarization, not automatic classful summarization; automatic summarization is controlled by the `auto-summary` command.

Practice this question →

39

Drag & Dropmedium

Drag and drop the steps for the EIGRP neighbor discovery process in the correct order.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

Why this order

EIGRP uses Hello packets to discover neighbors, then exchanges routes and maintains state.

Practice this question →

40

MCQeasy

What is the default hold time multiplier for EIGRP?

A.3

B.4

C.5

D.10

AnswerA

Correct. The hold time is typically three times the hello interval, so the multiplier is 3.

Why this answer

The default hold time multiplier for EIGRP is 3. This multiplier is applied to the hello interval to calculate the hold time (hold time = hello interval × multiplier). By default, EIGRP uses a hello interval of 5 seconds on most interfaces (or 60 seconds on low-speed NBMA interfaces), so the default hold time is 15 seconds (5 × 3) or 180 seconds (60 × 3).

Exam trap

Cisco often tests the default hold time multiplier (3) versus the default hold time (15 seconds), causing candidates to confuse the multiplier with the actual hold time value or to mistakenly recall the default hello interval (5 seconds) as the multiplier.

How to eliminate wrong answers

Option B (4) is wrong because the default EIGRP hold time multiplier is not 4; a multiplier of 4 would result in a hold time of 20 seconds (5 × 4), which is not the Cisco default. Option C (5) is wrong because a multiplier of 5 would yield a hold time of 25 seconds (5 × 5), which is not the standard default value. Option D (10) is wrong because a multiplier of 10 would produce a hold time of 50 seconds (5 × 10), far exceeding the default 15 seconds; this value is not used as the default multiplier in EIGRP.

Practice this question →

41

MCQmedium

Given the following EIGRP named mode configuration: router eigrp TEST address-family ipv4 unicast autonomous-system 100 network 10.0.0.0 0.255.255.255 topology base distance eigrp 90 170 exit-address-family Which statement is true?

A.The administrative distance for internal EIGRP routes is set to 90, and for external routes to 170.

B.The network statement will enable EIGRP on all interfaces with an IP address starting with 10.

C.The autonomous-system number must match the process ID in classic mode.

D.The 'topology base' command is optional and can be omitted.

AnswerA

Correct. The 'distance eigrp 90 170' command explicitly sets internal distance to 90 and external to 170.

Why this answer

The 'distance eigrp 90 170' command sets the administrative distance for internal EIGRP routes to 90 and for external routes to 170. Option B is incorrect because, in EIGRP named mode, the network statement does not enable EIGRP on interfaces; it only controls which networks are advertised. EIGRP is enabled on all interfaces by default.

Options C and D are incorrect: the autonomous-system number in named mode can differ from the process ID in classic mode, and the 'topology base' command is mandatory.

Exam trap

A common trap is to think the network statement enables EIGRP on interfaces in named mode. It actually only influences route advertisement; candidates misapply classic mode behavior.

How to eliminate wrong answers

Option B is wrong because the network statement 'network 10.0.0.0 0.255.255.255' uses a wildcard mask that matches only the first octet (10.x.x.x), but EIGRP named mode enables EIGRP only on interfaces whose primary IP address falls within the specified range; it does not enable EIGRP on all interfaces with an IP starting with 10 if the interface is not in the specified subnet. Option C is wrong because in EIGRP named mode, the autonomous-system number is specified within the address-family and does not need to match a classic mode process ID; classic mode uses 'router eigrp <ASN>' directly, while named mode separates the router name from the ASN. Option D is wrong because the 'topology base' command is mandatory in EIGRP named mode; it defines the base topology for the address-family and cannot be omitted, as it is required to enter the topology configuration mode where routing policies are applied.

Practice this question →

42

MCQmedium

A network engineer runs the following command on Router R1: R1# show ip eigrp neighbors EIGRP-IPv4 Neighbors for AS(100) H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 192.168.1.2 Gi0/0 13 00:12:34 12 100 0 45 1 10.1.1.2 Gi0/1 12 00:10:20 15 120 0 32 Based on this output, what can be concluded?

A.Both neighbors are using MD5 authentication.

B.Neighbor 192.168.1.2 has a higher metric than 10.1.1.2.

C.Both neighbors are fully established and exchanging routing information.

D.Router R1 is using EIGRP named mode.

AnswerC

The 'Q Cnt' of 0 and valid uptime indicate stable adjacencies.

Why this answer

The 'show ip eigrp neighbors' output displays two neighbors in a stable state, indicated by the 'Q Cnt' (Queue Count) of 0 for both, meaning no packets are waiting to be sent. The 'Seq Num' (Sequence Number) values (45 and 32) show that R1 has received and processed EIGRP updates from each neighbor, confirming the adjacency is fully established and routing information is being exchanged. This output does not provide any metric or authentication details, so only the conclusion that both neighbors are fully operational is valid.

Exam trap

Cisco often tests the misconception that the 'show ip eigrp neighbors' output reveals authentication status or metric values, but the table only shows transport-layer reliability statistics and adjacency state, not security or routing metric details.

How to eliminate wrong answers

Option A is wrong because the 'show ip eigrp neighbors' output does not include any authentication type or key information; MD5 or SHA authentication status is verified with 'show ip eigrp interfaces detail' or 'show key chain', not from the neighbor table. Option B is wrong because the neighbor table does not display route metrics; metrics are shown per route in the topology table ('show ip eigrp topology') or routing table, and the SRTT/RTO values here are timers for reliable transport, not metrics. Option D is wrong because the output shows 'EIGRP-IPv4 Neighbors for AS(100)', which is the classic EIGRP configuration format; named mode EIGRP would display 'EIGRP-IPv4 VR-FOO Neighbors' or similar with a VRF or named instance, not just the AS number.

Practice this question →

43

Drag & Dropmedium

Drag and drop the steps of EIGRP stub configuration for hub-and-spoke into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

In hub-and-spoke EIGRP, the spoke router is configured as a stub to limit query propagation. First, enter router configuration mode, then enable EIGRP on the spoke, configure it as a stub, optionally restrict advertised routes, and finally verify the stub status.

Practice this question →

44

Matchingmedium

Drag and drop each EIGRP router role on the left to its matching definition on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

Next-hop router with the lowest metric for a destination

Backup next-hop router meeting the feasibility condition

Directly connected EIGRP router exchanging Hello packets

Router is actively querying for a route

Router has a valid route and is not querying

Why these pairings

Successor is the next-hop router with the lowest metric; Feasible Successor is a backup that meets the feasibility condition; Neighbor is a directly connected EIGRP router.

Practice this question →

45

Matchingmedium

Drag and drop each EIGRP router role on the left to its matching definition on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

Next-hop router for the best route to a destination

Backup next-hop router meeting the feasibility condition

Directly connected EIGRP router exchanging Hello packets

Lowest metric to a destination from the local router

Metric advertised by a neighbor for a specific route

Why these pairings

In EIGRP, successors are the next-hop routers for the best path to a destination. Feasible successors serve as backup next-hop routers that meet the feasibility condition. Neighbors are directly connected EIGRP routers that exchange Hello packets.

Feasible Distance is the lowest metric from the local router to a destination. Reported Distance is the metric that a neighbor advertises for a specific route.

Practice this question →

46

MCQmedium

An enterprise network uses OSPF as its IGP. The network engineer notices that a particular route learned via OSPF is not being installed in the routing table, even though the neighbor adjacency is up and the route appears in the OSPF database. The route is an external route redistributed from EIGRP. What is the most likely cause?

A.The OSPF process ID is different on the routers.

B.The external route has a higher administrative distance than the internal route.

C.The forwarding address in the type 5 LSA is not reachable via an OSPF internal route.

D.The OSPF metric for the external route is too high.

AnswerC

Correct because OSPF requires the forwarding address to be reachable via an intra-area or inter-area route; otherwise, the external route is not installed.

Why this answer

OSPF requires the forwarding address (FA) in a Type 5 LSA to be reachable via an OSPF internal route (intra-area or inter-area) for the external route to be installed in the routing table. If the FA is not reachable, the router will ignore the LSA and not install the route, even though the LSA exists in the OSPF database and the neighbor adjacency is up.

Exam trap

Cisco often tests the forwarding address reachability requirement for Type 5 LSAs, and the trap here is that candidates assume any route in the OSPF database will automatically be installed, ignoring the recursive lookup condition for external routes with a non-zero forwarding address.

How to eliminate wrong answers

Option A is wrong because the OSPF process ID is locally significant and does not affect route installation between routers; different process IDs can still form adjacencies and exchange routes. Option B is wrong because OSPF external routes (type 5) have a default administrative distance of 110, while internal OSPF routes also have 110; the issue is not about AD comparison between internal and external OSPF routes, but about reachability of the forwarding address. Option D is wrong because a high OSPF metric does not prevent route installation; it only influences route selection among multiple paths; the route will still be installed if the metric is valid and the forwarding address is reachable.

Practice this question →

47

Matchingmedium

Drag and drop each EIGRP timer on the left to its matching default value on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

5 seconds

15 seconds

3 minutes

0.5 seconds

Why these pairings

EIGRP timers and their defaults: Hello timer defaults to 5 seconds on LAN interfaces; Hold timer defaults to 15 seconds (3 times Hello). Active timer defaults to 3 minutes. Retransmission timer defaults to 0.5 seconds.

There is no standard 'Update Timer' with a default of 5 seconds; the correct timer for 5 seconds is Hello, not Update.

Practice this question →

48

MCQeasy

What is the maximum hop count for EIGRP?

A.15

B.255

C.100

D.16

AnswerB

Correct. EIGRP supports a maximum hop count of 255.

Why this answer

EIGRP supports a maximum hop count of 255. Unlike RIP, which has a limit of 15 hops, EIGRP can scale to larger networks. The hop count is used as one component in the composite metric, but it is rarely the limiting factor in practice.

Practice this question →

49

MCQeasy

An enterprise network uses OSPF in the core and EIGRP in the campus distribution layer. The engineer needs to redistribute routes between the two protocols. Which design consideration is most important to prevent routing loops?

A.Set appropriate administrative distance values for redistributed routes.

B.Use route maps to filter all redistributed routes.

C.Enable OSPF on all EIGRP interfaces.

D.Use a single routing protocol throughout the network.

AnswerA

Correct because AD controls route preference; if not set correctly, a redistributed route could be preferred over the original, causing loops.

Why this answer

Setting appropriate administrative distance values for redistributed routes is crucial to prevent routing loops when redistributing between OSPF and EIGRP. By default, EIGRP has an administrative distance of 170 for external routes and 90 for internal routes, while OSPF uses 110. If redistributed routes are not assigned a higher administrative distance, a router might prefer a redistributed route over a directly learned route, creating a feedback loop where routes are re-injected into the original protocol.

Adjusting the administrative distance ensures that redistributed routes are less preferred than native routes, breaking the loop.

Exam trap

Cisco often tests the misconception that route filtering (option B) is the primary loop-prevention mechanism, but the real trap is that administrative distance must be adjusted to prevent the redistribution feedback loop, especially when multiple routers perform mutual redistribution.

How to eliminate wrong answers

Option B is wrong because using route maps to filter all redistributed routes is overly restrictive and can prevent necessary route propagation, but it does not directly address the root cause of routing loops, which is the preference for redistributed routes over native ones. Option C is wrong because enabling OSPF on all EIGRP interfaces would merge the two routing domains, defeating the purpose of redistribution and potentially causing instability, but it does not prevent loops in a multi-protocol environment. Option D is wrong because using a single routing protocol throughout the network is a valid design choice but is not a consideration for preventing loops during redistribution; the question specifically asks about redistributing between two protocols, so this option avoids the problem rather than solving it.

Practice this question →

50

MCQeasy

What is the maximum hop count for EIGRP?

A.100

B.15

C.255

D.16

AnswerA

Correct. The default maximum hop count is 100, configurable up to 255.

Why this answer

The maximum hop count for EIGRP is 100 by default, as defined in RFC 7868. This limit prevents routing loops in large networks by discarding routes that exceed 100 hops, unlike RIP's 15-hop limit. The hop count is a metric component in EIGRP's composite metric, but the protocol uses DUAL to ensure loop-free paths regardless of hop count.

Exam trap

Cisco often tests the EIGRP hop count limit to trick candidates who confuse it with RIP's 15-hop limit or OSPF's 255-hop limit, exploiting the common misconception that all distance-vector protocols share the same hop count restriction.

How to eliminate wrong answers

Option B is wrong because 15 is the maximum hop count for RIP (Routing Information Protocol), not EIGRP; this is a common confusion between distance-vector protocols. Option C is wrong because 255 is the maximum hop count for OSPF (Open Shortest Path First) as an age-based metric, not EIGRP. Option D is wrong because 16 is the 'unreachable' hop count in RIP, indicating an infinite metric, and has no relevance to EIGRP's hop count limit.

Practice this question →

51

MCQmedium

A network engineer runs the following command on Router R1: R1# show ip eigrp interfaces EIGRP-IPv4 Interfaces for AS(100) Interface Peers Xmit Queue Mean Pacing Time Multicast Pending Un/Reliable SRTT Un/Reliable Flow Timer Routes Gi0/0 1 0/0 12 0/10 50 0 Gi0/1 1 0/0 15 0/10 55 0 Based on this output, what can be concluded?

A.Interface Gi0/1 has higher latency than Gi0/0.

B.Both interfaces have pending routes to send.

C.The router is using EIGRP named mode.

D.There is a queue backlog on Gi0/0.

AnswerA

The Mean SRTT is higher on Gi0/1 (15 ms) compared to Gi0/0 (12 ms), indicating higher round-trip time.

Why this answer

The 'Mean SRTT' (Smooth Round-Trip Time) column shows the average time in milliseconds for EIGRP packets to reach a neighbor and receive an acknowledgment. Gi0/1 has an SRTT of 15 ms, while Gi0/0 has an SRTT of 12 ms, indicating higher latency on Gi0/1. This directly correlates to the path's delay, which EIGRP uses in its composite metric calculation.

Exam trap

Cisco often tests the ability to interpret the 'show ip eigrp interfaces' output, specifically the 'Mean SRTT' column, and the trap here is that candidates confuse SRTT with interface bandwidth or fail to recognize that a higher SRTT means higher latency, not necessarily a problem with queue or pending routes.

How to eliminate wrong answers

Option B is wrong because the 'Pending Routes' column shows 0 for both interfaces, meaning no routes are waiting to be sent. Option C is wrong because the command output shows 'EIGRP-IPv4 Interfaces for AS(100)', which is the classic mode format; named mode would display 'EIGRP-IPv4 (Address Family)' or similar. Option D is wrong because the 'Xmit Queue Un/Reliable' column shows 0/0 for Gi0/0, indicating no queue backlog.

Practice this question →

52

Matchingmedium

Drag and drop each EIGRP packet type on the left to its matching function on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

Discovers and maintains neighbor relationships

Sends routing information to neighbors

Requests information about a lost route

Responds to a query with routing information

Acknowledges receipt of a reliable packet

Why these pairings

Hello packets discover and maintain neighbors; Update packets carry routing information; Query packets ask for alternate paths; Reply packets respond to queries; ACK packets acknowledge reliable delivery.

Practice this question →

53

MCQeasy

What is the maximum hop count for EIGRP?

A.255

B.100

C.15

D.16

AnswerA

EIGRP supports up to 255 hops, configurable with the 'metric maximum-hops' command.

Why this answer

EIGRP uses a maximum hop count of 255, which is a hard limit encoded in the protocol's metric structure. This high limit allows EIGRP to scale in large enterprise networks without the hop-count restrictions of distance-vector protocols like RIP.

Exam trap

Cisco often tests the EIGRP hop count limit of 255 to catch candidates who confuse it with RIP's 15-hop limit or who assume all distance-vector protocols have the same constraints.

How to eliminate wrong answers

Option B (100) is wrong because EIGRP's maximum hop count is 255, not 100; 100 is not a standard limit in any major routing protocol. Option C (15) is wrong because that is the maximum hop count for RIP version 1 and 2, not EIGRP. Option D (16) is wrong because 16 represents 'infinite' or unreachable in RIP, but EIGRP uses a different metric system and a hop count of 255.

Practice this question →

54

MCQhard

Refer to the exhibit. A network engineer is troubleshooting a routing issue. The route for 10.0.0.0/8 is learned via EIGRP with metric 2560512. Which change would most likely cause the metric to increase?

A.Increase the bandwidth on GigabitEthernet0/0.

B.Add a redistribute static command under EIGRP.

C.Change the administrative distance to 90.

D.Increase the delay on GigabitEthernet0/0.

AnswerD

Correct.

Why this answer

The EIGRP metric is calculated using the formula: metric = (K1 * bandwidth + (K2 * bandwidth) / (256 - load) + K3 * delay) * 256, with default K values (K1=1, K3=1, others=0). Increasing the delay on the outgoing interface (GigabitEthernet0/0) directly increases the delay component in the composite metric, causing the overall metric to increase. Option D is correct because delay is a key variable in the EIGRP metric calculation.

Exam trap

Cisco often tests the misconception that increasing bandwidth increases the EIGRP metric, but the trap is that bandwidth is inversely proportional in the formula, so increasing bandwidth actually decreases the metric, while increasing delay directly increases it.

How to eliminate wrong answers

Option A is wrong because increasing bandwidth on GigabitEthernet0/0 would decrease the bandwidth component (since bandwidth is inversely proportional in the formula), thus decreasing the metric, not increasing it. Option B is wrong because adding a redistribute static command under EIGRP does not affect the metric of an already learned EIGRP route; it only influences redistribution of static routes into EIGRP, which is unrelated to the existing route's metric. Option C is wrong because changing the administrative distance to 90 (which is the default for EIGRP internal routes) does not alter the metric; administrative distance is a trustworthiness value used for route selection between different protocols, not a component of the EIGRP metric calculation.

Practice this question →

55

MCQhard

A network engineer runs the following command on Router R1: R1# show ip eigrp neighbors detail EIGRP-IPv4 Neighbors for AS(100) H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 192.168.1.2 Gi0/0 13 00:12:34 12 100 0 45 Version 2.0/2.0, Retrans: 0, Retry: 0, Maxseq: 0 Prefixes: 3 Topology ids: 0 Authentication: None Topology: base (0x0) Based on this output, what can be concluded?

A.The neighbor is using EIGRP version 1.

B.The neighbor has advertised 3 prefixes to R1.

C.There is a high number of retransmissions indicating packet loss.

D.The neighbor is using MD5 authentication.

AnswerB

The 'Prefixes: 3' field indicates the number of prefixes learned from this neighbor.

Why this answer

The output shows 'Prefixes: 3' under the neighbor details, which indicates that the neighbor has advertised exactly three prefixes to R1. This is a direct interpretation of the 'show ip eigrp neighbors detail' command, where the 'Prefixes' field lists the number of routes learned from that neighbor.

Exam trap

Cisco often tests the ability to read the 'show ip eigrp neighbors detail' output carefully, where candidates may confuse the 'Prefixes' field with the number of interfaces or ignore the 'Retrans' and 'Authentication' fields, leading them to select incorrect options based on assumptions rather than the explicit data shown.

How to eliminate wrong answers

Option A is wrong because the output shows 'Version 2.0/2.0', meaning both R1 and the neighbor are running EIGRP version 2, not version 1. Option C is wrong because the 'Retrans: 0' and 'Retry: 0' fields indicate zero retransmissions and retries, which means no packet loss is occurring. Option D is wrong because the output explicitly states 'Authentication: None', so MD5 authentication is not configured.

Practice this question →

56

MCQmedium

What is the maximum hop count for EIGRP?

A.15

B.100

C.255

D.Unlimited

AnswerB

EIGRP's default maximum hop count is 100, configurable up to 255.

Why this answer

EIGRP uses a maximum hop count of 100 by default, which is a loop-prevention mechanism. Unlike RIP's hard limit of 15 hops, EIGRP's hop count is not used for metric calculation but as a safety threshold; routes exceeding 100 hops are considered unreachable. This value can be modified with the 'metric maximum-hops' command under the EIGRP process.

Exam trap

Cisco often tests the distinction between EIGRP's hop count (default 100) and RIP's hop count (15), leading candidates to confuse the two or assume EIGRP uses 255 like OSPF.

How to eliminate wrong answers

Option A is wrong because 15 is the maximum hop count for RIP, not EIGRP; EIGRP's default is 100. Option C is wrong because 255 is the maximum hop count for OSPF (via the 'max-metric' or TTL-based mechanisms), not EIGRP. Option D is wrong because EIGRP does have a finite hop count limit (default 100), unlike BGP which has no hop count limit (uses AS-path instead).

Practice this question →

57

MCQmedium

Given the following Ansible playbook snippet: --- - name: Configure EIGRP hosts: routers gather_facts: no tasks: - name: EIGRP config ios_config: lines: - router eigrp 100 - network 192.168.1.0 parents: router eigrp 100 What is the effect of this playbook?

A.It fails because the network statement requires a wildcard mask.

B.It configures EIGRP AS 100 and advertises network 192.168.1.0/24.

C.It only enters EIGRP configuration mode without applying any network statement.

D.It works correctly because the network statement defaults to a classful mask.

AnswerA

Correct. EIGRP network statements need a wildcard mask; without it, the command is invalid.

Why this answer

The `network` statement in EIGRP requires a wildcard mask to define the exact interfaces on which EIGRP will run. Without a wildcard mask, the command `network 192.168.1.0` is incomplete and will be rejected by the Cisco IOS device, causing the playbook task to fail. The Ansible `ios_config` module sends the lines as-is to the device, so the missing wildcard mask results in a configuration error.

Exam trap

The trap here is that candidates often assume the `network` command in EIGRP defaults to a classful mask (like in older IOS versions or with RIP), but Cisco explicitly tests that EIGRP requires a wildcard mask, and omitting it causes a configuration failure.

How to eliminate wrong answers

Option B is wrong because the playbook does not actually configure EIGRP successfully; the missing wildcard mask causes the task to fail, so no network statement is applied. Option C is wrong because the playbook attempts to apply both the `router eigrp 100` and `network 192.168.1.0` lines, but the failure occurs before any configuration is committed; the `parents` directive only ensures the lines are placed under the EIGRP configuration mode, but the invalid network command still causes an error. Option D is wrong because EIGRP does not default to a classful mask; the `network` command in EIGRP explicitly requires a wildcard mask, unlike some other routing protocols (e.g., OSPF) that may accept a prefix length.

Practice this question →

58

Drag & Dropmedium

Drag and drop the steps of EIGRP named mode configuration steps into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

Named mode starts with the router eigrp <virtual-name> command, then enters address-family configuration, configures the network, and optionally adjusts timers or other parameters. Finally, the configuration is verified.

Practice this question →

59

MCQeasy

What is the maximum hop count for EIGRP?

A.100

B.255

C.15

D.Unlimited

AnswerB

EIGRP uses a maximum hop count of 255, which is encoded as a single octet in the route metric field, with 255 specifically reserved to indicate an unreachable route. This satisfies the constraint of limiting routing loops within an autonomous system, as EIGRP’s feasible successor logic and Diffusing Update Algorithm (DUAL) prevent counting to infinity beyond this hard limit.

Why this answer

EIGRP uses a maximum hop count of 255 to prevent routing loops, though in practice it relies on its DUAL algorithm and feasible successor logic rather than hop count as a primary loop-prevention mechanism. This value is hard-coded in the protocol and cannot be changed, unlike RIP's 15-hop limit.

Exam trap

Cisco often tests the EIGRP hop count limit of 255 to catch candidates who confuse it with RIP's 15-hop limit or mistakenly think EIGRP has no hop count restriction due to its advanced metric-based loop prevention.

How to eliminate wrong answers

Option A is wrong because 100 is not a hop count limit used by any dynamic routing protocol; it may be confused with the administrative distance of EIGRP internal routes (which is 90). Option C is wrong because 15 is the maximum hop count for RIP (RIPv1 and RIPv2), not EIGRP. Option D is wrong because EIGRP does have a finite hop count limit of 255; it is not unlimited, even though the protocol primarily uses composite metrics and DUAL for loop-free path selection.

Practice this question →

60

MCQmedium

Consider the following configuration snippet from a Cisco IOS-XE router: router eigrp 100 network 10.0.0.0 network 192.168.1.0 passive-interface default no passive-interface GigabitEthernet0/0 What is the effect of the passive-interface commands?

A.EIGRP hellos are suppressed on all interfaces except GigabitEthernet0/0.

B.EIGRP hellos are sent on all interfaces, but updates are blocked.

C.EIGRP adjacency is formed on all interfaces except GigabitEthernet0/0.

D.EIGRP is disabled on all interfaces.

AnswerA

The default passive suppresses hellos on all interfaces, and the no passive allows them on G0/0.

Why this answer

The command 'passive-interface default' makes all interfaces passive by default, meaning they will not send or receive EIGRP hellos. The subsequent 'no passive-interface GigabitEthernet0/0' overrides this for that specific interface, allowing EIGRP adjacency formation on it.

Practice this question →

61

Matchingmedium

Drag and drop each EIGRP timer on the left to its matching default value on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

5 seconds

15 seconds

3 minutes

60 seconds

180 seconds

Why these pairings

Hello timer default is 5 seconds on LAN; Hold timer default is 15 seconds; Active timer default is 3 minutes.

Practice this question →

62

MCQeasy

What is the maximum hop count for EIGRP?

A.15

B.255

C.16

D.100

AnswerB

Correct. EIGRP has a maximum hop count of 255.

Why this answer

EIGRP uses a maximum hop count of 255, which is a hard limit encoded in the protocol's metric field. This allows EIGRP to scale to much larger networks than distance-vector protocols like RIP, which have a hop count limit of 15. The hop count is not used as a primary metric in EIGRP but serves as a loop-prevention mechanism, and routes with a hop count exceeding 255 are considered unreachable.

Exam trap

Cisco often tests the difference between RIP's 15-hop limit and EIGRP's 255-hop limit, and the trap here is that candidates confuse the hop count limit with the administrative distance (100) or the RIP unreachable metric (16).

How to eliminate wrong answers

Option A is wrong because 15 is the maximum hop count for RIP (Routing Information Protocol), not EIGRP; this is a classic confusion between distance-vector protocols. Option C is wrong because 16 is the 'unreachable' metric in RIP, not a valid EIGRP hop count limit. Option D is wrong because 100 is the default administrative distance for EIGRP internal routes, not the maximum hop count.

Practice this question →

63

Multi-Selectmedium

Which two statements about EIGRP feasible successors are true? (Choose two.)

Select 2 answers

A.A feasible successor must have a reported distance less than the feasible distance.

B.A feasible successor is immediately used when the successor fails, without any query process.

C.The feasible distance is the metric of the feasible successor route.

D.EIGRP will always have at least one feasible successor for every route.

E.The feasible successor is stored in the routing table as a backup route.

AnswersA, B

Correct because the feasibility condition requires the reported distance (neighbor's metric) to be strictly less than the feasible distance (the current best metric).

Why this answer

A feasible successor is a backup route that meets the feasibility condition (reported distance < feasible distance). It is stored in the topology table and can be used immediately if the successor fails, without querying neighbors. The feasible distance is the lowest metric to a destination; the successor is the route with that metric.

The reported distance is the neighbor's metric to the destination.

Practice this question →

64

MCQmedium

What is the maximum hop count for EIGRP?

A.255

B.100

C.15

D.16

AnswerA

Correct. EIGRP supports up to 255 hops.

Why this answer

EIGRP uses a metric based on bandwidth and delay, but it also has a hop count limit. The maximum hop count for EIGRP is 255, though the default is 100.

Practice this question →

65

Matchingmedium

Drag and drop each EIGRP metric component on the left to its matching K variable on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

K1

K2

K3

K4

Why these pairings

In the EIGRP metric formula, the K values correspond to specific metric components: K1 is bandwidth, K2 is load, K3 is delay, K4 is reliability. MTU is not a K variable; the EIGRP metric does not include MTU.

Exam trap

MTU is not a K variable; K5 is not used in the standard EIGRP metric.

Practice this question →

66

Drag & Dropmedium

Drag and drop the steps of EIGRP variance-based unequal-cost load balancing into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

To enable unequal-cost load balancing, first ensure feasible successors exist, then set the variance multiplier, optionally adjust the metric offset, and finally verify the load sharing across multiple paths.

Practice this question →

67

MCQeasy

What is the maximum hop count for EIGRP?

A.255

B.15

C.100

D.16

AnswerA

Correct. EIGRP supports up to 255 hops.

Why this answer

EIGRP uses a maximum hop count of 255, which is the default and hard limit for the protocol. This is because EIGRP is a distance-vector protocol that uses hop count as one of its metrics, but unlike RIP (which has a limit of 15), EIGRP's DUAL algorithm allows for much larger networks without the same loop-prevention constraints.

Exam trap

Cisco often tests the difference between EIGRP's maximum hop count (255) and RIP's maximum hop count (15/16), tempting candidates who confuse the two distance-vector protocols or who mistakenly think all routing protocols have a low hop limit.

How to eliminate wrong answers

Option B (15) is wrong because 15 is the maximum hop count for RIP, not EIGRP; this is a common confusion between distance-vector protocols. Option C (100) is wrong because 100 is not a standard hop count limit for any major routing protocol; it may be confused with the default administrative distance for OSPF or EIGRP summary routes. Option D (16) is wrong because 16 is the 'unreachable' metric in RIP (hop count 16 means infinite), not a valid maximum for EIGRP.

Practice this question →

68

Drag & Dropmedium

Drag and drop the steps of EIGRP DUAL route computation into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

EIGRP DUAL first identifies feasible successors via reported distance, then selects the best path as successor. If the successor fails, it checks feasible successors; if none exist, it goes active and queries neighbors. After replies, it computes a new successor.

Practice this question →

69

MCQmedium

An engineer is troubleshooting an EIGRP convergence issue in a network with redundant links. The engineer notices that when a primary link fails, the backup link takes over immediately, but the routing table shows the route with a higher metric. The engineer wants to ensure that the backup link is used only when the primary fails, and that traffic is not load-balanced. The engineer has configured 'variance 2' on all routers. What is the most likely effect of this configuration?

A.The variance 2 command causes EIGRP to install only the best metric route, so the backup link is not used.

B.The variance 2 command causes EIGRP to install both the primary and backup routes, resulting in unequal-cost load balancing.

C.The variance 2 command has no effect on route installation; it only affects the feasible successor selection.

D.The variance 2 command is used for equal-cost load balancing only.

AnswerB

Correct. With variance 2, if the backup route's metric is within twice the best metric, it will be installed and used for load balancing, which the engineer does not want.

Why this answer

The 'variance 2' command in EIGRP allows the router to install multiple routes to the same destination network in the routing table, even if their metrics are not equal, as long as the metric of the alternate route is within the variance multiplier (2x) of the best metric (the feasible distance). Since the backup link has a higher metric but is within the variance, EIGRP installs both routes, causing unequal-cost load balancing. This explains why the backup link is actively used for traffic, contrary to the engineer's desire to use it only as a failover.

Exam trap

Cisco often tests the misconception that 'variance' only affects feasible successor selection or that it is used for equal-cost load balancing, when in fact it directly controls the installation of multiple unequal-cost paths into the routing table.

How to eliminate wrong answers

Option A is wrong because the 'variance 2' command does not restrict EIGRP to only the best metric route; it explicitly allows additional routes with higher metrics to be installed. Option C is wrong because the variance command directly affects route installation by allowing multiple routes into the routing table, not just feasible successor selection (which is controlled by the feasibility condition and the 'metric' command). Option D is wrong because the variance command is specifically designed for unequal-cost load balancing, not equal-cost load balancing (which is the default behavior without variance).

Practice this question →

70

MCQhard

A network engineer runs the following command on Router R1: R1# show ip eigrp traffic EIGRP-IPv4 Traffic Statistics for AS(100) Hellos sent/received: 1000/950 Updates sent/received: 45/40 Queries sent/received: 2/3 Replies sent/received: 3/2 Acks sent/received: 50/48 Input queue high water mark: 1 Input queue depth: 0 Total packets sent: 1100 Total packets received: 1043 Based on this output, what can be concluded?

A.The router has experienced many route flaps.

B.The network is stable with few topology changes.

C.The router is using EIGRP stub to suppress queries.

D.There is a high packet loss on the network.

AnswerB

Low query and reply counts indicate stable topology.

Why this answer

The output shows a very low number of EIGRP Queries (2 sent, 3 received) and Replies (3 sent, 2 received), which indicates that the network has experienced very few topology changes. A stable EIGRP network with minimal route flaps will have a high ratio of Hellos to Updates/Queries, as seen here (1000 Hellos vs. 45 Updates). Therefore, the network is stable with few topology changes, making option B correct.

Exam trap

Cisco often tests the misconception that a high number of Hellos indicates instability or that a small difference between sent and received packets automatically means packet loss, when in fact EIGRP Hellos are sent unreliably (multicast) and may be lost without retransmission, so a small discrepancy is normal.

How to eliminate wrong answers

Option A is wrong because route flaps would generate a high number of Updates and Queries, but the output shows only 45 Updates sent and 2 Queries sent, which is very low. Option C is wrong because the output does not show any evidence of EIGRP stub configuration; stub routers suppress queries entirely, but here queries are still being sent and received (2 sent, 3 received), indicating stub is not in use. Option D is wrong because packet loss would be reflected in a mismatch between sent and received packets (e.g., Hellos sent 1000 vs. received 950 is a 5% difference, which is normal for EIGRP due to timing and multicast delivery, not indicative of high loss; total sent 1100 vs. received 1043 is a 5.2% difference, which is typical in a healthy network).

Practice this question →

71

Drag & Dropmedium

Drag and drop the steps of EIGRP route summarization configuration into the correct order, from first to last.

Drag steps to the numbered slots on the right, or tap a step then tap a slot.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

5Step 5

Why this order

EIGRP route summarization first requires enabling EIGRP, configuring the network statement, then entering interface configuration mode, applying the summary-address command, and finally verifying the summary route in the routing table.

Practice this question →

72

MCQhard

A network engineer runs the following command on Router R1: R1# show ip eigrp topology 10.1.1.0/24 EIGRP-IPv4 Topology Entry for AS(100)/ID(192.168.1.1) for 10.1.1.0/24 State: Passive, Reply status: 0, Originating router: 192.168.1.1 Routing Descriptor Blocks: 0.0.0.0 (Null0), from 0.0.0.0, Send flag: 0x0 Composite metric: (128256/0), Route is Internal Vector metric: Minimum bandwidth: 1000000 Kbit Total delay: 100 microseconds Reliability: 255/255 Load: 1/255 Minimum MTU: 1500 Hop count: 0 192.168.1.2 (GigabitEthernet0/0), from 192.168.1.2, Send flag: 0x0 Composite metric: (1310720/128256), Route is Internal Vector metric: Minimum bandwidth: 1000000 Kbit Total delay: 1100 microseconds Reliability: 255/255 Load: 1/255 Minimum MTU: 1500 Hop count: 1 Based on this output, what can be concluded?

A.The route 10.1.1.0/24 is learned from neighbor 192.168.1.2 and is the successor.

B.The router has a feasible successor for this route.

C.The route is directly connected on Router R1.

D.The router is in Active state for this route.

AnswerC

The Null0 entry with metric 128256/0 indicates a connected route.

Why this answer

The presence of a Null0 route in the EIGRP topology table with a composite metric of (128256/0) and a hop count of 0 indicates that Router R1 has a directly connected interface on the 10.1.1.0/24 network. EIGRP automatically installs a summary or connected route to Null0 to prevent routing loops, and the metric (128256/0) with hop count 0 confirms it is locally originated, not learned from a neighbor.

Exam trap

Cisco often tests the misconception that a Null0 route in the EIGRP topology table indicates a summary or redistributed route, when in fact it confirms a directly connected network; candidates mistakenly assume the neighbor route must be the successor because it has a next-hop IP address.

How to eliminate wrong answers

Option A is wrong because the route learned from neighbor 192.168.1.2 has a composite metric of (1310720/128256), which is higher than the Null0 route's metric (128256/0); the successor is the best path, which is the directly connected Null0 route, not the neighbor route. Option B is wrong because a feasible successor requires a reported distance (RD) less than the feasible distance (FD) of the successor; here the only neighbor route has an RD of 128256, which is equal to the FD of the Null0 route (128256), so it does not meet the feasibility condition (RD < FD). Option D is wrong because the output shows 'State: Passive', meaning the router is not performing Diffusing Update Algorithm (DUAL) computations for this route; an Active state would indicate the router is actively querying neighbors for a lost route.

Practice this question →

73

MCQhard

An engineer is troubleshooting an EIGRP issue where a router is not learning a specific route from a neighbor. The engineer runs 'show ip eigrp topology all-links' and sees the route in the topology table with a feasible distance of 100 and a reported distance of 120. The neighbor's advertised distance is 80. The router's own computed distance to the network is 150. The route is not in the routing table. What is the most likely cause?

A.The route is a feasible successor, but the successor route is not present.

B.The route is not installed because the reported distance (80) from the neighbor is less than the feasible distance (100), but the router's computed distance (150) is higher.

C.The route is not installed because its metric (150) is not the best metric; the router has another route with a lower metric (100).

D.The route is not installed because EIGRP is configured for stub routing, which prevents learning routes.

AnswerC

The route in the topology table has a computed distance of 150, which is higher than the feasible distance (FD) of 100. EIGRP only installs the successor route (lowest metric) into the routing table, so this route is not installed because it is not the best path.

Why this answer

The route in the topology table has a computed distance of 150 via the neighbor, but the feasible distance (FD) for this destination is 100, which is the best metric from another neighbor. EIGRP installs only the route with the lowest metric (the successor) into the routing table. Since the computed distance of 150 is higher than the FD of 100, this route is not the best and is not installed.

Option C correctly identifies that the route is not installed because there is another route with a lower metric.

Exam trap

Candidates often confuse the feasible distance (FD) with the computed distance of a specific path. Here, the FD is 100 from a different neighbor, but the route in question has a computed distance of 150—it is not the successor. The route is not installed because it is not the best path, not because of any feasibility condition issue.

How to eliminate wrong answers

Option A is wrong because a feasible successor is a backup route that meets the feasibility condition (reported distance < feasible distance), but the route is not installed as a feasible successor if the successor route is present; the issue is that the route is not in the routing table, not that the successor is missing. Option B is wrong because the reported distance (80) from the neighbor is less than the feasible distance (100), which actually satisfies the feasibility condition, but the router's computed distance (150) being higher than the FD (100) means this route is not the best path; the route is not installed because the router has a better path (FD 100), not because of the reported distance comparison. Option D is wrong because stub routing prevents the router from learning routes from neighbors, but the router is learning the route (it appears in the topology table), so stub routing is not the cause; the issue is about route selection, not route learning.

Practice this question →

74

MCQmedium

Consider the following EIGRP configuration: router eigrp 100 metric weights 0 1 0 1 0 0 What does this configuration accomplish?

A.It sets the EIGRP metric to use bandwidth and delay only, which is the default behavior.

B.It disables the use of bandwidth in the metric calculation.

C.It enables the use of load and reliability in the metric calculation.

D.It changes the metric to use only delay.

AnswerA

Correct. The default K values are k1=1, k2=0, k3=1, k4=0, k5=0, so this command explicitly sets them to the default.

Why this answer

The `metric weights` command in EIGRP allows you to modify the K values used in the composite metric calculation. The default K values are K1=1, K2=0, K3=1, K4=0, K5=0, which means only bandwidth (K1) and delay (K3) are used. The configuration `metric weights 0 1 0 1 0 0` explicitly sets K1=1, K2=0, K3=1, K4=0, K5=0, which matches the default behavior.

Therefore, option A is correct.

Exam trap

Cisco often tests the misconception that the `metric weights` command changes the metric calculation from the default, when in fact the given values exactly match the default K values (1,0,1,0,0).

How to eliminate wrong answers

Option B is wrong because the configuration sets K1=1, which enables the use of bandwidth in the metric calculation, not disables it. Option C is wrong because the configuration sets K2=0 and K4=0, which disables load and reliability, respectively; enabling them would require K2=1 and K4=1. Option D is wrong because the configuration sets K1=1, so bandwidth is still included; to use only delay, you would need K1=0 and K3=1.

Practice this question →

75

Matchingmedium

Drag and drop each EIGRP DUAL state on the left to its matching stage on the right.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

Route is stable and no queries are pending

Router is querying neighbors for a new route

Router uses a feasible successor without querying

Router queries all neighbors for a new route

Router that first sends a query for a lost route

Why these pairings

Passive state indicates a stable route; Active state indicates the router is querying neighbors; Local Computation occurs when a feasible successor exists; Diffusing Computation occurs when no feasible successor exists; Query Origin is the router that starts the query process.

Practice this question →

Page 1 of 2 · 92 questions totalNext →

Ready to test yourself?

Try a timed practice session using only Eigrp questions.

Start 20-question session BGP Questions →