Eigrp practice questions

Examine the following EIGRP configuration snippet:

interface GigabitEthernet0/0
 ip bandwidth-percent eigrp 100 50

What is the effect of this command?

Trap 1: EIGRP will only advertise routes that have a metric within 50% of…

Incorrect. This command does not affect route selection; it only controls bandwidth usage for EIGRP packets.

Trap 2: EIGRP will use 50% of the interface bandwidth for data traffic.

Incorrect. This command specifically controls EIGRP control traffic, not data traffic.

Trap 3: EIGRP will reduce its hello interval by 50%.

Incorrect. The command does not affect hello intervals.

A
EIGRP will use up to 50% of the interface bandwidth for its control traffic.
Correct. This command limits EIGRP's bandwidth usage to 50% of the interface's configured bandwidth.
B
EIGRP will only advertise routes that have a metric within 50% of the best path.
Why wrong: Incorrect. This command does not affect route selection; it only controls bandwidth usage for EIGRP packets.
C
EIGRP will use 50% of the interface bandwidth for data traffic.
Why wrong: Incorrect. This command specifically controls EIGRP control traffic, not data traffic.
D
EIGRP will reduce its hello interval by 50%.
Why wrong: Incorrect. The command does not affect hello intervals.

Question 2hardmultiple choice

A network engineer is configuring EIGRP on a router that connects to a service provider network. The engineer wants to advertise a default route to internal routers. The engineer configures 'ip default-network 0.0.0.0' and redistributes a static default route into EIGRP. However, internal routers are not receiving the default route. The engineer checks the EIGRP topology table and sees the default route with a metric of 1. What is the most likely reason?

Trap 1: The engineer used 'ip default-network' which is not supported in…

Ly states that 'default-information originate' should be used for EIGRP. That command is for OSPF, not EIGRP. While 'ip default-network' is indeed not supported in EIGRP, the correct method is to redistribute a properly configured static default route, not to use 'default-information originate'. Therefore, this is not the most likely reason.

Trap 2: The internal routers have a route to the default network with a…

Internal routers are not receiving the default route at all, so they cannot have a route with a better metric from another source. This option describes a scenario where the route is received but not preferred, which does not match the problem.

Trap 3: The engineer needs to configure 'eigrp stub' on the router to allow…

Configuring 'eigrp stub' on the router would restrict route advertisement, not allow it. To advertise a default route from a stub router, you would need the 'summary' keyword, but the router is not necessarily a stub. This would not be the most likely reason for the failure.

A
The engineer used 'ip default-network' which is not supported in EIGRP; instead, 'default-information originate' should be used.
Why wrong: Ly states that 'default-information originate' should be used for EIGRP. That command is for OSPF, not EIGRP. While 'ip default-network' is indeed not supported in EIGRP, the correct method is to redistribute a properly configured static default route, not to use 'default-information originate'. Therefore, this is not the most likely reason.
B
The static default route is not configured correctly; the engineer should use 'ip route 0.0.0.0 0.0.0.0 <next-hop>'.
Correct. The static default route must be correctly configured with a next-hop IP address. If the static route is missing or uses an interface instead of a next-hop, it may not be valid, and the redistribution will not propagate the route to internal routers, despite appearing in the topology table with a metric.
C
The internal routers have a route to the default network with a better metric from another source.
Why wrong: Internal routers are not receiving the default route at all, so they cannot have a route with a better metric from another source. This option describes a scenario where the route is received but not preferred, which does not match the problem.
D
The engineer needs to configure 'eigrp stub' on the router to allow default route advertisement.
Why wrong: Configuring 'eigrp stub' on the router would restrict route advertisement, not allow it. To advertise a default route from a stub router, you would need the 'summary' keyword, but the router is not necessarily a stub. This would not be the most likely reason for the failure.

Question 3mediummultiple choice

Examine the following EIGRP configuration on a Cisco IOS-XE device:

router eigrp 100
 network 10.0.0.0 0.255.255.255
 passive-interface default
 no passive-interface GigabitEthernet0/0

interface GigabitEthernet0/0
 ip address 10.1.1.1 255.255.255.0

interface GigabitEthernet0/1
 ip address 10.2.2.1 255.255.255.0

Which statement is true?

Trap 1: EIGRP will form adjacencies on both GigabitEthernet0/0 and…

Incorrect. Only GigabitEthernet0/0 is explicitly set to not be passive. GigabitEthernet0/1 remains passive and will not form adjacencies.

Trap 2: EIGRP will not form any adjacencies because the network command…

Incorrect. The network 10.0.0.0 0.255.255.255 matches both interfaces (10.1.1.1 and 10.2.2.1).

Trap 3: EIGRP will form adjacencies on all interfaces except those with…

Incorrect. The 'passive-interface default' makes all interfaces passive unless overridden with 'no passive-interface'.

A
EIGRP will form adjacencies on both GigabitEthernet0/0 and GigabitEthernet0/1.
Why wrong: Incorrect. Only GigabitEthernet0/0 is explicitly set to not be passive. GigabitEthernet0/1 remains passive and will not form adjacencies.
B
EIGRP will form an adjacency only on GigabitEthernet0/0.
Correct. GigabitEthernet0/0 is not passive, so it will send and receive hellos. GigabitEthernet0/1 is passive by default.
C
EIGRP will not form any adjacencies because the network command does not match the interface subnets.
Why wrong: Incorrect. The network 10.0.0.0 0.255.255.255 matches both interfaces (10.1.1.1 and 10.2.2.1).
D
EIGRP will form adjacencies on all interfaces except those with 'passive-interface' configured.
Why wrong: Incorrect. The 'passive-interface default' makes all interfaces passive unless overridden with 'no passive-interface'.

Question 4mediummultiple choice

Given the following EIGRP configuration on a router:

router eigrp 200
 network 192.168.1.0 0.0.0.255
 network 10.0.0.0

Which statement about this configuration is true?

Trap 1: Both network statements are classful and will enable EIGRP on all…

Incorrect. The first network statement includes a wildcard mask, making it not classful.

Trap 2: EIGRP will only be enabled on interfaces with an IP address in the…

Incorrect. The second network statement will also enable EIGRP on interfaces in the 10.0.0.0/8 range.

Trap 3: This configuration will cause an error because wildcard masks are…

Incorrect. Wildcard masks are allowed in EIGRP network statements in classic mode.

A
EIGRP will be enabled on any interface with an IP address in the 10.0.0.0/8 range, and only on interfaces with an IP address in the 192.168.1.0/24 range.
Correct. The first network statement uses a wildcard mask to specify the exact subnet, while the second is classful.
B
Both network statements are classful and will enable EIGRP on all interfaces with IP addresses in the 192.168.0.0/16 and 10.0.0.0/8 ranges.
Why wrong: Incorrect. The first network statement includes a wildcard mask, making it not classful.
C
EIGRP will only be enabled on interfaces with an IP address in the 192.168.1.0/24 range.
Why wrong: Incorrect. The second network statement will also enable EIGRP on interfaces in the 10.0.0.0/8 range.
D
This configuration will cause an error because wildcard masks are not allowed in EIGRP network statements.
Why wrong: Incorrect. Wildcard masks are allowed in EIGRP network statements in classic mode.

Question 5mediumdrag order

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

Question 6mediumdrag order

Review the full OSPF breakdown →

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

Question 7mediumdrag order

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

Question 8mediummatching

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

Trap 1: Update Timer: 5 seconds

Incorrect: EIGRP does not have a standard 'Update Timer' with a default of 5 seconds. The 5-second default belongs to the Hello timer.

A
Hello Timer: 5 seconds
Correct: Hello timer default is 5 seconds on LAN.
B
Hold Timer: 15 seconds
Correct: Hold timer default is 15 seconds (3x Hello).
C
Active Timer: 3 minutes
Correct: Active timer default is 3 minutes.
D
Update Timer: 5 seconds
Why wrong: Incorrect: EIGRP does not have a standard 'Update Timer' with a default of 5 seconds. The 5-second default belongs to the Hello timer.
E
Retransmission Timer: 0.5 seconds
Correct: Retransmission timer default is 0.5 seconds.

Question 9mediummultiple choice

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?

Trap 1: The 'eigrp stub' command prevents the spoke from learning routes…

Incorrect. The stub command affects what the spoke advertises, not what it learns. Spoke routers can still learn routes from the hub.

Trap 2: The hub router is also configured as stub, which prevents route…

Incorrect. If the hub is stub, it would not advertise routes to spokes, but the scenario implies the hub was working before.

Trap 3: The spoke routers have a different EIGRP autonomous system number…

Incorrect. If AS numbers differ, no adjacency would form, but the scenario says they were learning routes before.

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.
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.
B
The 'eigrp stub' command prevents the spoke from learning routes from the hub.
Why wrong: Incorrect. The stub command affects what the spoke advertises, not what it learns. Spoke routers can still learn routes from the hub.
C
The hub router is also configured as stub, which prevents route propagation.
Why wrong: Incorrect. If the hub is stub, it would not advertise routes to spokes, but the scenario implies the hub was working before.
D
The spoke routers have a different EIGRP autonomous system number than the hub.
Why wrong: Incorrect. If AS numbers differ, no adjacency would form, but the scenario says they were learning routes before.

Review the full OSPF breakdown →

Question 10mediumdrag order

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

Question 11easymatching

Drag and drop each protocol number on the left to its matching protocol on the right.

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

Concepts

Matches

Internet Control Message Protocol (ICMP)

Transmission Control Protocol (TCP)

User Datagram Protocol (UDP)

Open Shortest Path First (OSPF)

Enhanced Interior Gateway Routing Protocol (EIGRP)

Question 12mediummultiple choice

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?

Trap 1: Split horizon

Split horizon prevents updates from being sent out the interface they were learned on.

Trap 2: Route poisoning

Route poisoning sets the metric to infinity to indicate a down route.

Trap 3: Hold-down timers

Hold-down timers are used in RIP, not EIGRP, to prevent loop information from being used.

A
Split horizon
Why wrong: Split horizon prevents updates from being sent out the interface they were learned on.
B
Route poisoning
Why wrong: Route poisoning sets the metric to infinity to indicate a down route.
C
Hold-down timers
Why wrong: Hold-down timers are used in RIP, not EIGRP, to prevent loop information from being used.
D
Feasibility condition
The feasibility condition ensures loop-free paths by verifying that the neighbor's reported distance is lower than the feasible distance.

Question 13mediumdrag order

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

Question 14mediummultiple choice

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?

Trap 1: It creates a summary route 10.0.0.0/8 with a metric of 5, but only…

The command is correct, but the metric value is actually the administrative distance, not the metric.

Trap 2: It creates a summary route 10.0.0.0/8 with a hop count of 5.

EIGRP does not use hop count; the value is the administrative distance.

Trap 3: The command is invalid because the summary address must match the…

The summary address can be a supernet of the network statement; this is valid.

A
It creates a summary route 10.0.0.0/8 with a metric of 5, advertised out GigabitEthernet0/0.
The summary address is 10.0.0.0/8, and the value 5 is the administrative distance for the summary route.
B
It creates a summary route 10.0.0.0/8 with a metric of 5, but only for the EIGRP process named TEST.
Why wrong: The command is correct, but the metric value is actually the administrative distance, not the metric.
C
It creates a summary route 10.0.0.0/8 with a hop count of 5.
Why wrong: EIGRP does not use hop count; the value is the administrative distance.
D
The command is invalid because the summary address must match the network statement exactly.
Why wrong: The summary address can be a supernet of the network statement; this is valid.

Question 15hardmultiple choice

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?

Trap 1: The hub router is configured with 'no ip next-hop-self eigrp' under…

Incorrect because disabling next-hop-self would actually help spokes learn the real next hop of remote spokes. The issue is that next-hop-self is still enabled, causing spokes to see the hub as the next hop.

Trap 2: The spoke routers have 'ip nhrp shortcut' configured but the hub…

Incorrect. NHRP redirect is used on the hub to inform spokes that a better path exists. Without it, spokes may still forward through the hub, but the primary cause here is the next-hop-self behavior in EIGRP.

Trap 3: The spoke routers are using static NHRP mappings to the hub only,…

Incorrect. Dynamic NHRP registration is needed for spokes to learn each other, but the scenario describes correct NHRP and mGRE configuration. The routing protocol's next-hop behavior is the key issue.

A
The hub router is configured with 'no ip next-hop-self eigrp' under the tunnel interface.
Why wrong: Incorrect because disabling next-hop-self would actually help spokes learn the real next hop of remote spokes. The issue is that next-hop-self is still enabled, causing spokes to see the hub as the next hop.
B
The hub router is configured with 'ip next-hop-self eigrp' under the tunnel interface.
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.
C
The spoke routers have 'ip nhrp shortcut' configured but the hub does not have 'ip nhrp redirect'.
Why wrong: Incorrect. NHRP redirect is used on the hub to inform spokes that a better path exists. Without it, spokes may still forward through the hub, but the primary cause here is the next-hop-self behavior in EIGRP.
D
The spoke routers are using static NHRP mappings to the hub only, without dynamic NHRP registration.
Why wrong: Incorrect. Dynamic NHRP registration is needed for spokes to learn each other, but the scenario describes correct NHRP and mGRE configuration. The routing protocol's next-hop behavior is the key issue.

Question 16mediummultiple choice

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?

Trap 1: EIGRP will only accept routes within the 192.168.0.0/22 range on…

Incorrect. This command is for advertising, not filtering incoming routes.

Trap 2: The summary route will have a metric equal to the best metric among…

Incorrect. The metric is derived from the component routes, but it is not necessarily the best metric; it is typically the best metric of the component routes, but the statement is not precise enough. The correct answer is A.

Trap 3: This command will cause EIGRP to automatically summarize routes to…

Incorrect. Automatic summarization is disabled by default in EIGRP for IPv4. This command is manual summarization.

A
EIGRP will advertise the 192.168.0.0/22 summary route out of GigabitEthernet0/0 and create a discard route.
Correct. The summary-address command creates a summary route and a corresponding discard route.
B
EIGRP will only accept routes within the 192.168.0.0/22 range on this interface.
Why wrong: Incorrect. This command is for advertising, not filtering incoming routes.
C
The summary route will have a metric equal to the best metric among the component routes.
Why wrong: Incorrect. The metric is derived from the component routes, but it is not necessarily the best metric; it is typically the best metric of the component routes, but the statement is not precise enough. The correct answer is A.
D
This command will cause EIGRP to automatically summarize routes to their classful boundaries.
Why wrong: Incorrect. Automatic summarization is disabled by default in EIGRP for IPv4. This command is manual summarization.

Question 17easymultiple choice

What is the default hold time multiplier for EIGRP?

Trap 1: 4

Incorrect. The default multiplier is 3, not 4.

Trap 2: 5

Incorrect. The default multiplier is 3.

Trap 3: 10

Incorrect. The default multiplier is 3.

A
3
Correct. The hold time is typically three times the hello interval, so the multiplier is 3.
B
4
Why wrong: Incorrect. The default multiplier is 3, not 4.
C
5
Why wrong: Incorrect. The default multiplier is 3.
D
10
Why wrong: Incorrect. The default multiplier is 3.

Question 18mediummultiple choice

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?

Trap 1: The network statement will enable EIGRP on all interfaces with an…

Incorrect. 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.

Trap 2: The autonomous-system number must match the process ID in classic…

Incorrect. The autonomous-system number in named mode can differ from the process ID in classic mode.

Trap 3: The 'topology base' command is optional and can be omitted.

Incorrect. The 'topology base' command is mandatory in EIGRP named mode.

A
The administrative distance for internal EIGRP routes is set to 90, and for external routes to 170.
Correct. The 'distance eigrp 90 170' command explicitly sets internal distance to 90 and external to 170.
B
The network statement will enable EIGRP on all interfaces with an IP address starting with 10.
Why wrong: Incorrect. 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.
C
The autonomous-system number must match the process ID in classic mode.
Why wrong: Incorrect. The autonomous-system number in named mode can differ from the process ID in classic mode.
D
The 'topology base' command is optional and can be omitted.
Why wrong: Incorrect. The 'topology base' command is mandatory in EIGRP named mode.

Question 19mediummultiple choice

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?

Trap 1: EIGRP will send updates on all interfaces except GigabitEthernet0/0.

The passive-interface default makes all interfaces passive; the 'no passive-interface' overrides that for Gi0/0, so only Gi0/0 sends updates.

Trap 2: EIGRP will not send any updates because the network statement is…

The network statement is valid (wildcard mask 0.255.255.255 matches 10.0.0.0/8).

Trap 3: EIGRP will form adjacencies on all interfaces that have an IP…

The passive-interface default prevents adjacencies on all interfaces except those with 'no passive-interface'.

A
EIGRP will send and receive updates only on GigabitEthernet0/0.
All interfaces are passive by default, but Gi0/0 is explicitly enabled for EIGRP updates.
B
EIGRP will send updates on all interfaces except GigabitEthernet0/0.
Why wrong: The passive-interface default makes all interfaces passive; the 'no passive-interface' overrides that for Gi0/0, so only Gi0/0 sends updates.
C
EIGRP will not send any updates because the network statement is incorrect.
Why wrong: The network statement is valid (wildcard mask 0.255.255.255 matches 10.0.0.0/8).
D
EIGRP will form adjacencies on all interfaces that have an IP address in the 10.0.0.0/8 range.
Why wrong: The passive-interface default prevents adjacencies on all interfaces except those with 'no passive-interface'.

Question 20easymultiple choice

What is the maximum hop count for EIGRP?

Trap 1: 100

Incorrect. 100 is the default hop count, but the maximum is 255.

Trap 2: 15

Incorrect. 15 is the maximum for RIP.

Trap 3: 16

Incorrect. 16 is the infinity metric for RIP.

A
255
Correct. EIGRP's maximum hop count is 255.
B
100
Why wrong: Incorrect. 100 is the default hop count, but the maximum is 255.
C
15
Why wrong: Incorrect. 15 is the maximum for RIP.
D
16
Why wrong: Incorrect. 16 is the infinity metric for RIP.