Refer to the Exhibit Practice Questions

An engineer redistributes OSPF routes into EIGRP. The OSPF routes have a metric of 20. After redistribution, the EIGRP topology table shows the routes but they are not installed in the routing table. The 'show ip eigrp topology' shows the route in active state. Which is the most likely explanation?

A
The 'default-metric' command was not configured, so the routes are redistributed with an infinite metric.
Why wrong: Infinite metric would show the route in passive state but not installed.
B
The EIGRP neighbor is stuck-in-active because a query was sent but no reply was received due to a unidirectional link.
Active state indicates a query is outstanding, often due to a unidirectional link.
C
The OSPF routes are external type 2, which are not redistributed by default.
Why wrong: OSPF external routes are redistributed by default.
D
The 'route-map' used for redistribution has a 'match ip address' that does not match the OSPF routes.
Why wrong: If route-map denies, the route would not appear in topology table.

Question 2hardmultiple choice

EIGRP network is experiencing stuck-in-active (SIA) routes. Router R1 shows: show ip eigrp topology active includes 10.0.0.0/24. Router R2 has: interface GigabitEthernet0/0, ip summary-address eigrp 100 10.0.0.0 255.255.255.0. What is the root cause?

A
The summary address on R2 is causing a query for the specific route to be suppressed.
Summary addresses can cause queries to be aggregated, leading to SIA if replies are not received.
B
R1 has a stuck interface causing the SIA.
Why wrong: SIA is due to query/reply issues, not interface state.
C
EIGRP is misconfigured with wrong autonomous system number.
Why wrong: AS number mismatch would prevent neighbor formation.
D
The route 10.0.0.0/24 is flapping, causing continuous queries.
Why wrong: Flapping can cause SIA, but the summary is the direct cause here.

Question 3hardmultiple choice

An engineer configures EIGRP named mode on a router. A route is learned via EIGRP, but the router does not install it in the routing table. The show ip eigrp topology shows the route in passive state with a feasible distance. Which is the most likely explanation?

A
The route is an external route and the EIGRP administrative distance is set to 255.
Why wrong: AD of 255 means route is not installed, but this is not default.
B
The router is configured as an EIGRP stub with 'receive-only', which prevents it from installing any EIGRP routes.
Stub receive-only blocks all EIGRP routes from being installed.
C
The 'metric weights' command is misconfigured, causing incorrect metric calculation.
Why wrong: Metric weights affect path selection, not installation.
D
The route is a summary route that is not advertised due to 'summary-address' configuration.
Why wrong: Summary routes are created locally, not learned.

Question 4mediummultiple choice

A network engineer is troubleshooting a route redistribution issue between two EIGRP processes. Router R1 runs EIGRP AS 100 and EIGRP AS 200, and redistributes routes between them. The engineer notices that routes from EIGRP AS 100 are not appearing in the EIGRP topology table of AS 200 on R1. The redistribute eigrp 100 command is configured under EIGRP AS 200. What is the most likely cause?

A
The redistribute eigrp 100 command under EIGRP AS 200 is missing the metric specification.
Correct: Without a metric, EIGRP does not accept redistributed routes.
B
EIGRP AS 100 has a higher administrative distance than EIGRP AS 200.
Why wrong: Administrative distance is not relevant when redistributing between processes on the same router.
C
The redistribute eigrp 100 command under EIGRP AS 200 is missing the subnets keyword.
Why wrong: The subnets keyword is not used in EIGRP redistribution.
D
EIGRP AS 200 has a route map that is filtering all routes.
Why wrong: While possible, the missing metric is a more common and likely cause.

Question 5mediummultiple choice

Which OSPF LSA type is flooded only within the originating area and is used for loop prevention by describing the topology of the area?

A
Type 1 LSA (Router LSA)
Correct. Router LSAs are area-scoped and describe the router's interfaces and neighbors.
B
Type 2 LSA (Network LSA)
Why wrong: Incorrect. Network LSAs are also area-scoped but describe multi-access networks, not individual routers.
C
Type 3 LSA (Summary LSA)
Why wrong: Incorrect. Summary LSAs are flooded between areas, not confined to a single area.
D
Type 4 LSA (ASBR Summary LSA)
Why wrong: Incorrect. ASBR Summary LSAs are flooded between areas to advertise ASBR location.

Question 6hardmultiple choice

A network engineer is troubleshooting IPv6 redistribution between EIGRP and OSPFv3 on Router R1. Routes from OSPFv3 are being redistributed into EIGRP, but they are not appearing in the EIGRP topology table. Router R1 has the following relevant configuration:

router eigrp Test

address-family ipv6 unicast redistribute ospf 1 metric 10000 100 255 1 1500 !

Router R2 shows: show ipv6 eigrp topology output does not include any OSPF-derived routes. What is the root cause?

A
The EIGRP metric values are too high, causing the routes to be considered unreachable.
Why wrong: Metric values are within typical ranges; they would still appear in the topology table.
B
The OSPFv3 process ID in the redistribute command does not match the actual OSPFv3 process ID running on the router.
If the process ID is wrong, the redistribution command does not match any OSPFv3 process, and no routes are redistributed.
C
The routes from OSPFv3 are external, and EIGRP does not redistribute external OSPF routes by default.
Why wrong: The redistribute command includes all OSPF routes unless filtered.
D
The EIGRP address-family is not configured with a router ID, preventing redistribution.
Why wrong: EIGRP for IPv6 does not require a router ID for redistribution.

Question 7mediummultiple choice

A network engineer runs the following command on Router R1:

R1# show ip eigrp topology 10.0.0.0 255.255.252.0

IP-EIGRP (AS 100): Topology entry for 10.0.0.0/22 State: Passive, Origin: Internal, Metric [90/2172416], Tag 0 Number of successors: 1 FD is 2172416, Serno: 5 Route is Summary Advertised by R2 (via Serial0/0/0) Reply status: 0

Based on this output, what is true about the route 10.0.0.0/22?

A
The route is a summary route generated by R1.
Why wrong: The route is advertised by R2, not generated by R1.
B
The route is a summary route learned from R2.
The output shows 'Advertised by R2' and 'Route is Summary', indicating it is a summary route received from neighbor R2.
C
The route is an external route redistributed into EIGRP.
Why wrong: The origin is Internal, not External.
D
The route is in active state and being queried.
Why wrong: The state is Passive, not Active.

Question 8hardmultiple choice

A network engineer is troubleshooting a route redistribution issue between OSPF and EIGRP. Routers R1 (OSPF) and R2 (EIGRP) are redistributing routes. The engineer notices that some OSPF routes are appearing in the EIGRP topology table on R2, but traffic to those destinations is being dropped. The show ip route command on R2 shows the redistributed routes with a next-hop of the R1 interface, but the route is not installed in the routing table. What is the most likely cause?

A
The redistribute ospf command under EIGRP is missing the default-metric configuration.
Correct: Without a default-metric, EIGRP may not install redistributed routes if the metric is not set properly.
B
OSPF has a higher administrative distance than EIGRP.
Why wrong: Administrative distance affects route selection, but the route is not installed at all.
C
The EIGRP process on R2 has a distribute-list blocking these routes.
Why wrong: If a distribute-list were blocking, the routes would not appear in the topology table.
D
The OSPF process on R1 has a route filter blocking these routes.
Why wrong: The issue is on R2, not R1.

Question 9easymultiple choice

A network engineer runs the following command to troubleshoot an Administrative Distance issue:

R1# show ip ospf interface detail GigabitEthernet0/0

GigabitEthernet0/0 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0, Attached via Network Statement Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1 Topology-MTID Cost Disabled Shutdown Topology Name 0 1 no no Base Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 1.1.1.1, Interface address 10.1.1.1 Backup Designated router (ID) 2.2.2.2, Interface address 10.1.1.2 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:03 Supports Link-local Signaling (LLS) Cisco NSF helper support enabled IETF NSF helper support enabled Can be protected by per-prefix Loop-Free Fast Reroute Can be used for per-prefix Loop-Free Fast Reroute remote-LFA tunnels Index 1/1/1, flood queue length 0 Next 0x0(0)/0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 2.2.2.2 (Backup Designated Router) Suppress hello for 0 neighbor(s)

What does this output indicate?

A
The interface is an OSPF broadcast interface with a cost of 1, and the router is the Designated Router.
The output clearly states State DR, indicating this router is the Designated Router on this segment.
B
The interface has an administrative distance of 110.
Why wrong: Administrative distance is not shown in this output; it is a per-protocol value.
C
The neighbor 2.2.2.2 is not fully adjacent because it is a backup designated router.
Why wrong: The neighbor is listed as Adjacent, meaning full adjacency.
D
The OSPF process ID is 100.
Why wrong: The process ID is 1, not 100.

Question 10hardmultiple choice

A DMVPN Phase 3 network with EIGRP as the routing protocol experiences intermittent connectivity between spokes. R1 (hub) has 'ip summary-address eigrp 100 10.0.0.0 255.255.0.0' configured on the tunnel interface. R2 (spoke) shows 'show ip eigrp topology all-links' listing 10.1.0.0/24 as reachable via R1, but traffic from R2 to 10.1.0.1 (another spoke) is forwarded to R1 instead of directly via the spoke-to-spoke tunnel. What is the root cause?

A
The summary route on the hub creates a less specific route that is preferred over the more specific /24 routes learned from other spokes, causing suboptimal routing.
Correct. EIGRP summary routes have administrative distance 5 by default, which is lower than the distance of learned routes (90/170). This causes spokes to prefer the summary route and forward traffic to the hub, even though more specific routes exist.
B
EIGRP stub configuration on spokes prevents them from learning routes from other spokes.
Why wrong: Incorrect. EIGRP stub configuration would limit route advertisement, but the issue is about route preference, not learning.
C
NHRP redirect is disabled on the hub, preventing spoke-to-spoke tunnel establishment.
Why wrong: Incorrect. NHRP redirect is required for Phase 3, but even if enabled, the summary route would still be preferred.
D
The spoke-to-spoke tunnel interface has a different MTU causing fragmentation.
Why wrong: Incorrect. MTU mismatch would cause packet drops, not suboptimal routing.

Question 11hardmultiple choice

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 10.10.10.0/24, 1 successors, FD is 28160 via 10.1.1.2 (28160/28160), GigabitEthernet0/0 P 10.20.20.0/24, 1 successors, FD is 28160 via 10.2.2.2 (28160/28160), GigabitEthernet0/1 P 10.30.30.0/24, 1 successors, FD is 28160 via 10.3.3.2 (28160/28160), GigabitEthernet0/2 A 10.40.40.0/24, 0 successors, FD is Infinity via 10.4.4.2 (Infinity/Infinity), GigabitEthernet0/3

Based on this output, what is the problem?

A
The route to 10.40.40.0/24 is stuck-in-active and may cause a network instability.
A route in Active state with no successor indicates that the router is querying neighbors and has not received a reply, which can lead to SIA.
B
The route to 10.40.40.0/24 is passive and stable.
Why wrong: The code 'A' indicates Active, not Passive.
C
The route to 10.30.30.0/24 has a feasible successor.
Why wrong: The output shows only one successor for 10.30.30.0/24; no feasible successor is listed.
D
All routes are in a stable passive state.
Why wrong: The route to 10.40.40.0/24 is Active, so not all routes are passive.

Question 12mediummultiple choice

A network engineer runs the following command to troubleshoot a Control Plane Policing (CoPP) issue:

R1# show ip ospf interface detail

FastEthernet0/0 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0.0.0.0, Attached via Network Statement Process ID 1, Router ID 10.1.1.1, Network Type BROADCAST, Cost: 1 Topology-MTID Cost Disabled Shutdown Topology Name 0 1 no no Base Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 10.1.1.1, Interface address 10.1.1.1 Backup Designated router (ID) 10.1.1.2, Interface address 10.1.1.2 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:03 Supports Link-local Signaling (LLS) Index 1/1, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 25 Last flood scan time is 0 msec, maximum is 4 msec

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 10.1.1.2 (Backup Designated Router) Suppress hello for 0 neighbor(s)

What does this output indicate?

A
OSPF is not forming adjacencies due to CoPP dropping Hello packets.
Why wrong: The output shows one adjacent neighbor, so adjacencies are formed.
B
OSPF is operating normally with one neighbor, suggesting CoPP is not impacting OSPF.
The interface is up, timers are normal, and an adjacency exists.
C
OSPF is experiencing DR/BDR election issues due to CoPP.
Why wrong: The router is DR, and the neighbor is BDR, indicating a successful election.
D
OSPF is not receiving Hello packets due to CoPP.
Why wrong: The neighbor count of 1 indicates Hello packets are being received.