Courseiva

CCNA Route Redistribution Questions

75 of 76 questions · Page 1/2 · Route Redistribution topic · Answers revealed

Practice these questionsExam hubAll questions
1
MCQhard

A network administrator configures an ACL to filter routes during redistribution, but management traffic stops working. Router R1 config: access-list 100 permit ip 10.0.0.0 0.255.255.255 any ! router eigrp 100 redistribute ospf 1 route-map FILTER ! route-map FILTER permit 10 match ip address 100 R1# show ip route 10.1.1.1 Routing entry for 10.1.1.1/32 Known via "connected", distance 0, metric 0 Redistributing via eigrp 100 What is the root cause?

A.The ACL implicit deny blocks all routes not matching 10.0.0.0/8, including management routes.
B.The route-map is missing the set metric command, causing routes to be unreachable.
C.The access-list is applied in the wrong direction.
D.The redistribute command is missing the subnets keyword.
AnswerA

The implicit deny at the end of the ACL filters out management routes, causing them not to be redistributed.

Why this answer

The ACL only permits 10.0.0.0/8, but the management traffic may use a different source or destination. The implicit deny at the end of the ACL blocks all other routes, including management prefixes. The fix is to add a permit statement for the management network or use a more specific ACL.

Practice this question →
2
MCQmedium

A network engineer is troubleshooting a route redistribution issue between OSPF and EIGRP. Routers R1 (OSPF) and R2 (EIGRP) are redistributing routes into each other. The engineer notices that some OSPF external routes are not appearing in the EIGRP topology table on R2, although the redistribution is configured. The show ip eigrp topology command on R2 does not list the missing prefixes. What is the most likely cause?

A.The redistribute ospf command under EIGRP is missing the match internal keyword.
B.The redistribute ospf command under EIGRP is missing the match external keyword.
C.The OSPF process on R1 has a route filter blocking external routes.
D.EIGRP has a lower administrative distance than OSPF, causing route suppression.
AnswerB

Correct: Without match external, OSPF external routes are not redistributed into EIGRP.

Why this answer

When redistributing from OSPF into EIGRP, by default only OSPF internal routes are redistributed; external OSPF routes (type 5 or 7) are not included unless the match external keyword is specified. This explains why some routes are missing.

Practice this question →
3
MCQmedium

A network engineer is troubleshooting a route redistribution issue between EIGRP and OSPF. Routers R1 (EIGRP) and R2 (OSPF) are redistributing routes. The engineer notices that some EIGRP external routes (redistributed into EIGRP from another protocol) are not appearing in the OSPF database on R2. The show ip ospf database external command on R2 does not list these prefixes. What is the most likely cause?

A.The redistribute eigrp command under OSPF is missing the subnets keyword.
B.The redistribute eigrp command under OSPF is missing the match external keyword.
C.EIGRP has a higher administrative distance than OSPF, causing route suppression.
D.The OSPF process on R2 has a distribute-list blocking these routes.
AnswerB

Correct: Without match external, EIGRP external routes are not redistributed into OSPF.

Why this answer

When redistributing from EIGRP into OSPF, by default only EIGRP internal routes are redistributed; EIGRP external routes are not included unless the match external keyword is specified.

Practice this question →
4
MCQhard

A network engineer configures DMVPN Phase 2 with NHRP. Spoke routers can communicate with the hub, but spoke-to-spoke traffic fails. The 'show dmvpn' on spokes shows the hub's NBMA address but not other spokes. Which is the most likely explanation?

A.The hub is configured with 'ip nhrp redirect' but spokes are missing 'ip nhrp shortcut'.
B.The tunnel interface mode is GRE IP, not mGRE.
C.The spokes have different IPsec transform sets configured.
D.The NHRP authentication string is missing on the hub.
AnswerA

Without 'ip nhrp shortcut' on spokes, they will not install dynamic NHRP entries.

Why this answer

In DMVPN Phase 2, spoke-to-spoke tunnels require NHRP redirect from the hub and NHRP shortcut on spokes. If the hub is not sending NHRP redirect messages (e.g., due to 'no ip nhrp redirect'), spokes will not learn each other's NBMA addresses, and traffic will be sent through the hub.

Practice this question →
5
Drag & Dropmedium

Drag and drop the steps to troubleshoot route redistribution adjacency or connectivity failures 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

Troubleshooting connectivity failures due to redistribution starts with checking basic Layer 3 reachability, then verifying routing protocol adjacencies, followed by examining the redistribution configuration, then checking for route filtering issues, and finally testing end-to-end connectivity. This order isolates the problem systematically.

Practice this question →
6
MCQmedium

Examine this partial configuration on Router R3: router ospf 1 redistribute rip subnets metric-type 1 metric 50 What is the effect of the 'metric-type 1' keyword?

A.Redistributed RIP routes become OSPF Type 1 external LSAs, and the metric is the sum of the external metric (50) plus the internal OSPF cost to the ASBR.
B.Redistributed RIP routes become OSPF Type 2 external LSAs with a fixed metric of 50.
C.The 'metric-type 1' is ignored because the 'metric' keyword is also used.
D.The redistributed routes will have a metric of 50 and will not be affected by internal OSPF cost.
AnswerA

Type 1 external LSAs add internal OSPF cost to the external metric.

Why this answer

The metric-type 1 keyword makes the redistributed routes Type 1 external LSAs, which add the internal OSPF cost to the external metric. Type 2 (default) does not add internal cost.

Practice this question →
7
MCQhard

An engineer configures BGP between two routers in the same AS. The iBGP session is established, but routes learned from the eBGP neighbor are not advertised to the iBGP peer. The 'show ip bgp' output shows the routes as valid but not best. Which is the most likely explanation?

A.The 'synchronization' rule is enabled and the IGP does not carry the prefix.
B.The next-hop IP of the eBGP route is not reachable via IGP, making the route invalid.
C.The 'maximum-paths' command is set to 1, preventing load balancing.
D.The 'bgp bestpath med missing-as-worst' command causes the route to be considered worse.
AnswerB

iBGP requires next-hop reachability; without next-hop-self, the next-hop is the eBGP peer's IP.

Why this answer

For iBGP, the next-hop must be reachable via IGP. If the next-hop is not reachable (e.g., no IGP route for the eBGP peer's interface IP), the route is considered invalid and not installed. This is a common edge case where next-hop-self is not configured.

Practice this question →
8
MCQhard

An experienced network engineer configures mutual redistribution between OSPF and EIGRP on a router. Both protocols have routes to the same prefix, but after redistribution, a routing loop occurs. The engineer did not use route tagging. Which is the most likely explanation?

A.The seed metric for EIGRP was not configured, causing routes to be rejected.
B.The redistribute command without route-map or tag allows routes to be re-advertised back into the source protocol, creating a loop.
C.OSPF has a lower administrative distance than EIGRP, so OSPF routes are always preferred.
D.EIGRP stub configuration on the redistributing router prevents routes from being advertised.
AnswerB

Mutual redistribution without tagging and filtering causes a feedback loop.

Why this answer

Without route tagging, redistributed routes are re-injected back into the original protocol, causing a feedback loop. Administrative distance comparison (OSPF 110 vs EIGRP 90/170) can cause suboptimal path selection, but the loop is primarily due to lack of tagging and filtering.

Practice this question →
9
MCQeasy

When redistributing routes from EIGRP into OSPF, what is the default OSPF metric assigned to redistributed routes if no metric is specified?

A.20
B.1
C.10
D.0
AnswerA

The default metric for redistributed routes into OSPF is 20.

Why this answer

Cisco IOS assigns a default metric of 20 to redistributed routes from other protocols into OSPF if no metric is explicitly configured. This is defined in Cisco's implementation.

Practice this question →
10
MCQmedium

When redistributing routes between OSPF and EIGRP, which of the following is a recommended best practice to prevent routing loops?

A.Use the same administrative distance for both protocols.
B.Apply route filtering using route-maps or prefix-lists to control which routes are redistributed.
C.Increase the default metric to a high value to discourage redistribution.
D.Disable route summarization on both protocols.
AnswerB

Route filtering prevents unwanted routes from being redistributed, reducing loop risk.

Why this answer

To prevent routing loops during mutual redistribution, it is recommended to use route-maps with distribute-lists or prefix-lists to filter routes, and to adjust administrative distances to prefer one protocol over the other. This prevents routes from being redistributed back and forth.

Practice this question →
11
Multi-Selecthard

Which TWO statements correctly describe the behavior of the 'default-information originate' command in the context of route redistribution? (Choose TWO.)

Select 2 answers
A.In OSPF, the 'default-information originate' command always injects a default route into the OSPF domain, even if no default route exists in the routing table, provided the 'always' keyword is used.
B.In EIGRP, the 'redistribute static' command automatically injects a default route if a static default route is configured.
C.In EIGRP, the 'default-information originate' command will inject a default route only if a default route is present in the routing table, unless the 'always' keyword is configured.
D.In OSPF, the 'default-information originate always' command will inject a default route even if OSPF is not configured on any interface.
E.In both OSPF and EIGRP, the 'default-information originate' command automatically redistributes all connected routes into the routing protocol.
AnswersA, C

Correct. The 'always' keyword forces OSPF to originate a default route even if no default route is present in the routing table.

Why this answer

The 'default-information originate' command in OSPF and EIGRP has specific behaviors. In OSPF, it always originates a default route regardless of the routing table, unless the 'always' keyword is omitted and there is no default route in the routing table. In EIGRP, it requires a default route in the routing table to inject the default, unless the 'always' keyword is used.

The command does not automatically redistribute all routes; it only injects a default route.

Practice this question →
12
Multi-Selecthard

Which TWO statements about redistributing connected routes into a routing protocol are true? (Choose TWO.)

Select 2 answers
A.The 'redistribute connected' command will redistribute all interfaces that are up/up, including loopback interfaces, unless filtered.
B.To redistribute only specific connected interfaces, a route map with 'match interface' can be used with the 'redistribute connected' command.
C.The 'redistribute connected' command requires a corresponding 'network' statement under the routing protocol to include those interfaces.
D.Redistributing connected routes automatically includes the default route (0.0.0.0/0) if one is present.
E.The 'redistribute connected' command is only available in OSPF and EIGRP, not in other routing protocols like RIP.
AnswersA, B

Correct. By default, 'redistribute connected' redistributes all active connected interfaces, including loopbacks, unless a route map or distribute list filters them out.

Why this answer

Redistributing connected routes can be done explicitly with the 'redistribute connected' command or implicitly by using the 'redistribute static' command if a static route points to the interface. The 'redistribute connected' command does not require a network statement under the routing protocol. However, redistributing connected routes does not automatically include loopback interfaces unless they are explicitly matched or included.

The 'default-information originate' command does not redistribute connected routes.

Practice this question →
13
MCQhard

Examine this configuration on Router R6: router ospf 1 redistribute eigrp 100 subnets default-information originate always What is a likely problem with this configuration?

A.The 'default-information originate always' command is not allowed with redistribution.
B.The router will advertise a default route into OSPF even if it does not have a default route itself, potentially causing blackholing.
C.The 'subnets' keyword is missing for EIGRP redistribution.
D.The redistribution will only work if EIGRP routes have a metric set.
AnswerB

The 'always' keyword forces the default route advertisement regardless of the local routing table.

Why this answer

The 'default-information originate always' will generate a default route into OSPF regardless of whether a default route exists in the routing table. This can cause routing issues if the router does not actually have a default route, as it will attract traffic for unknown destinations.

Practice this question →
14
Multi-Selecthard

Which THREE symptoms indicate a problem with route redistribution causing suboptimal routing or routing loops? (Choose THREE.)

Select 3 answers
A.Routing loops occur where packets traverse multiple routers repeatedly.
B.Traffic from one area takes a longer path than expected, even though a shorter path exists within the same routing domain.
C.CPU utilization on the redistribution router is consistently below 50%.
D.Some networks are not reachable from certain parts of the network, even though they are present in the routing table of the redistribution router.
E.The routing table on all routers is stable and converges quickly after a topology change.
AnswersA, B, D

Correct: This is a classic symptom of mutual redistribution without proper filtering.

Why this answer

Route redistribution issues often manifest as routing loops, suboptimal paths, or missing routes. A routing loop (option A) occurs when redistributed routes are re-injected back into the source protocol. Suboptimal routing (option B) happens when a router prefers a redistributed route over a more direct one.

Missing routes (option D) can occur if redistribution is not configured or if filters block routes. Option C is incorrect because high CPU may indicate many things, not specifically redistribution. Option E is incorrect because a stable routing table does not indicate a problem.

Practice this question →
15
MCQmedium

Consider the following partial configuration on Router R1: router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 router ospf 1 redistribute eigrp 100 subnets Which statement about this configuration is true?

A.Redistributed OSPF routes into EIGRP will have a default metric of 10000 100 255 1 1500.
B.OSPF routes redistributed into EIGRP will have a metric of 20 by default.
C.EIGRP routes redistributed into OSPF will be Type 1 external LSAs.
D.The 'subnets' keyword in OSPF redistribution is optional but recommended.
AnswerA

The 'metric' keyword in the redistribute command sets the EIGRP metric for all redistributed routes.

Why this answer

The configuration redistributes OSPF routes into EIGRP with specific bandwidth, delay, reliability, load, and MTU metrics. The 'subnets' keyword in OSPF redistribution ensures that all subnets (including classless prefixes) are redistributed. Without 'subnets', only classful networks are redistributed.

Practice this question →
16
MCQmedium

In EIGRP, which of the following K values is disabled by default, meaning it is not used in the metric calculation?

A.K5 (MTU)
B.K1 (bandwidth)
C.K3 (delay)
D.K2 (load)
AnswerA

K5 is set to 0 by default, so MTU is not used in metric calculation.

Why this answer

By default, EIGRP uses K1 (bandwidth) and K3 (delay) with values of 1, and K2 (load), K4 (reliability), and K5 (MTU) are set to 0, meaning they are not used. K5 is disabled by default.

Practice this question →
17
MCQmedium

A network engineer is troubleshooting a route redistribution issue between RIP and OSPF. Router R1 runs both RIP and OSPF, and redistributes RIP routes into OSPF. The engineer notices that RIP routes are not appearing in the OSPF database on neighboring routers. The show ip ospf database external command on a neighbor shows no external routes from R1. The redistribute rip command is configured under OSPF on R1. What is the most likely cause?

A.The redistribute rip command under OSPF is missing the subnets keyword.
B.RIP has a higher administrative distance than OSPF.
C.The OSPF process on R1 has a distribute-list blocking these routes.
D.The RIP process on R1 is not running.
AnswerA

Correct: Without subnets, only classful networks are redistributed, causing missing routes.

Why this answer

When redistributing into OSPF, the subnets keyword is required to redistribute classless subnets. Without it, only classful networks are advertised, which may cause many routes to be missing.

Practice this question →
18
Multi-Selecthard

Which THREE statements about route redistribution and administrative distance are true? (Choose THREE.)

Select 3 answers
A.EIGRP external routes (redistributed) have a default administrative distance of 170.
B.OSPF external routes (type 1 and type 2) have a default administrative distance of 110.
C.Adjusting administrative distance can be used to influence route selection and prevent routing loops during redistribution.
D.The 'distance' command in OSPF can only be applied to external routes, not internal routes.
E.When redistributing RIP into OSPF, the redistributed routes will have a lower administrative distance than OSPF internal routes.
AnswersA, B, C

Correct: EIGRP uses AD 170 for external routes, while internal routes use 90.

Why this answer

Administrative distance (AD) is crucial in redistribution because it determines which routes are preferred when multiple protocols learn the same prefix. Option A is correct: EIGRP has a default AD of 90 for internal routes and 170 for external (redistributed) routes. Option B is correct: OSPF external routes have a default AD of 110, same as internal OSPF routes, but can be changed.

Option C is correct: Changing AD can influence route selection and help prevent routing loops. Option D is incorrect: The distance command can be applied to both internal and external routes. Option E is incorrect: RIP has a default AD of 120, which is higher than OSPF's 110, so OSPF is preferred.

Practice this question →
19
MCQmedium

A network engineer runs the following command on Router R1: R1# show ip bgp 10.1.1.0/24 BGP routing table entry for 10.1.1.0/24, version 10 Paths: (1 available, best #1, table default) Advertised to update-groups: 1 Refresh Epoch 1 Local 10.2.2.2 from 10.2.2.2 (2.2.2.2) Origin IGP, metric 0, localpref 100, valid, external, best rx pathid: 0, tx pathid: 0x0 Community: 100:200 Based on this output, what is the problem?

A.The route 10.1.1.0/24 is learned via an eBGP session and has a local preference of 100.
B.The route 10.1.1.0/24 is redistributed from an IGP into BGP, as indicated by the 'Local' path.
C.The community 100:200 is automatically assigned by BGP for all redistributed routes.
D.The route is not being advertised to any peers because it is not marked as best.
AnswerB

The 'Local' path attribute in BGP indicates the route was originated locally via network statement or redistribution from an IGP.

Why this answer

The output shows a BGP route with 'Local' as the path, meaning it was redistributed into BGP locally. The origin is IGP, and the community is 100:200. The route is valid and best.

However, the 'Local' path indicates redistribution from an IGP into BGP, which is common in redistribution scenarios.

Practice this question →
20
MCQhard

A network engineer runs the following command on Router R1: R1# show ip bgp neighbors 10.2.2.2 advertised-routes BGP table version is 10, local router ID is 1.1.1.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 10.1.1.0/24 0.0.0.0 0 32768 i *> 10.2.2.0/24 0.0.0.0 0 32768 i Total number of prefixes 2 Based on this output, what is the problem?

A.The routes are correctly advertised with next hop 0.0.0.0, which is normal for locally originated routes.
B.The routes are not being advertised to eBGP peers because the next hop is 0.0.0.0, which is invalid for eBGP.
C.The routes are being advertised to iBGP peers only, as indicated by the next hop 0.0.0.0.
D.The routes are redistributed from an IGP into BGP, and the next hop is correctly set to 0.0.0.0.
AnswerB

For eBGP, the next hop must be reachable; 0.0.0.0 is not a valid next hop for eBGP advertisements, so the routes may not be installed by the peer.

Why this answer

The output shows that R1 is advertising two routes to neighbor 10.2.2.2: 10.1.1.0/24 and 10.2.2.0/24, both with next hop 0.0.0.0. In BGP, a next hop of 0.0.0.0 means the route is originated locally (via network statement or redistribution). The problem is that the next hop should be the router's own interface IP when advertising to an eBGP neighbor, but 0.0.0.0 is used for local routes.

This could indicate that the routes are not being advertised correctly to eBGP peers because the next hop is not updated.

Practice this question →
21
MCQhard

After redistributing OSPF into EIGRP, an EIGRP router becomes stuck-in-active (SIA) for certain routes. Router R1 config: router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 ! router ospf 1 redistribute eigrp 100 subnets R1# show ip eigrp topology 10.0.0.0/8 IP-EIGRP (AS 100): Topology entry for 10.0.0.0/8 State: Active, 0:01:15, Reply count: 0 Originating router: 10.1.1.1 Last sent query: 10.1.1.2 What is the root cause?

A.The redistributed OSPF route is a summary that causes EIGRP queries to go unanswered, leading to SIA.
B.The EIGRP metric is too high, causing the route to be unreachable.
C.The OSPF redistribution is missing the subnets keyword, causing classful behavior.
D.The EIGRP AS number is mismatched between routers.
AnswerA

Summary routes can cause queries to propagate widely; if a neighbor has no route, the query times out.

Why this answer

The EIGRP route for 10.0.0.0/8 is in Active state, meaning it is waiting for replies from neighbors. The redistribution from OSPF may be injecting a summary route that causes a query to be sent to all neighbors, but one neighbor may not have a route back, causing the query to be unanswered. The fix is to ensure that the redistributed routes are not summarized or to use a stub router to limit query scope.

Practice this question →
22
MCQhard

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.
B.The router is configured as an EIGRP stub with 'receive-only', which prevents it from installing any EIGRP routes.
C.The 'metric weights' command is misconfigured, causing incorrect metric calculation.
D.The route is a summary route that is not advertised due to 'summary-address' configuration.
AnswerB

Stub receive-only blocks all EIGRP routes from being installed.

Why this answer

In named mode, EIGRP uses address-family configuration. The route may be learned but not installed if the 'no ip route-cache' or 'no ip routing' is misconfigured, or if the route is suppressed by a route-map. However, a common edge case is that the route is an internal route but the router is configured as a stub with 'receive-only', which prevents installing any routes.

Practice this question →
23
MCQeasy

What is the default seed metric used by Cisco IOS when redistributing routes into RIP?

A.0
B.1
C.15
D.16
AnswerA

RIP uses a default metric of 0 for redistributed routes, meaning they are not advertised until a metric is set.

Why this answer

By default, RIP assigns a seed metric of 0 to redistributed routes, which makes them unreachable unless a metric is explicitly configured.

Practice this question →
24
MCQhard

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.
B.OSPF has a higher administrative distance than EIGRP.
C.The EIGRP process on R2 has a distribute-list blocking these routes.
D.The OSPF process on R1 has a route filter blocking these routes.
AnswerA

Correct: Without a default-metric, EIGRP may not install redistributed routes if the metric is not set properly.

Why this answer

When redistributing from OSPF into EIGRP, the redistributed routes may have a next-hop that is not reachable via EIGRP, causing the route to be not installed in the routing table. This is often due to the default-metric not being set, causing EIGRP to use an incorrect metric.

Practice this question →
25
Multi-Selecteasy

Which TWO commands would a network engineer use to verify the results of route redistribution from OSPF into EIGRP? (Choose TWO.)

Select 2 answers
A.show ip route eigrp
B.show ip ospf database
C.show ip protocols
D.show ip eigrp topology
E.show ip eigrp traffic
AnswersA, D

Correct: This shows EIGRP routes in the routing table, including redistributed routes.

Why this answer

To verify redistribution, you can check the routing table to see if redistributed routes appear, and you can check the EIGRP topology table to see if they are learned via redistribution. Option A is correct because 'show ip route eigrp' displays EIGRP routes, including redistributed ones. Option D is correct because 'show ip eigrp topology' shows all EIGRP routes and their sources.

Option B is incorrect because 'show ip ospf database' shows OSPF LSAs, not redistributed routes. Option C is incorrect because 'show ip protocols' shows routing protocol parameters but not specific redistributed routes. Option E is incorrect because 'show ip eigrp traffic' shows packet statistics, not route information.

Practice this question →
26
MCQmedium

A network engineer runs the following command on Router R1: R1# show ip ospf interface GigabitEthernet0/1 GigabitEthernet0/1 is up, line protocol is up Internet Address 10.1.1.1/24, Area 0 Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1 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 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 2.2.2.2 (Backup Designated Router) Suppress hello for 0 neighbor(s) Based on this output, what is the problem?

A.The router is the DR, which is normal, but the neighbor count of 1 indicates only one OSPF neighbor is present.
B.The interface is in area 0, but redistribution of external routes requires a route-map to set the metric.
C.The output shows no external routes are being redistributed, but this is a normal interface status.
D.The router ID is 1.1.1.1, which is not reachable from other routers.
AnswerC

The interface output is normal; redistribution status is not shown here. The candidate must understand that this command does not show redistribution information.

Why this answer

The output shows R1 is the Designated Router (DR) on a broadcast network. The neighbor count is 1, which is normal. However, the problem might be that redistribution is not happening because the interface is in area 0, but no external routes are seen.

The output itself does not show a direct problem; it is a normal OSPF interface state. The question likely expects the candidate to note that the interface is functioning correctly, but the context of redistribution might imply that redistribution is configured but not working due to other issues.

Practice this question →
27
MCQhard

A network engineer is troubleshooting a route redistribution issue between OSPF and BGP. Router R1 runs both OSPF and BGP, and redistributes OSPF routes into BGP. The engineer notices that OSPF external routes are not appearing in the BGP table on R1. The show ip bgp command does not list these prefixes. The redistribute ospf 1 match external command is configured under BGP. What is the most likely cause?

A.The redistribute ospf 1 match external command under BGP is missing the subnets keyword.
B.OSPF has a higher administrative distance than BGP.
C.The OSPF process on R1 has a distribute-list blocking these routes.
D.BGP requires the network command to advertise routes, not redistribution.
AnswerA

Correct: Without subnets, only classful networks are redistributed, causing missing routes.

Why this answer

When redistributing OSPF into BGP, the subnets keyword is required to redistribute classless subnets. Without it, only classful networks are redistributed, which may cause many routes to be missing.

Practice this question →
28
MCQhard

When redistributing OSPF into EIGRP, which EIGRP metric components are used to calculate the default metric?

A.Bandwidth and delay only
B.Bandwidth, delay, reliability, load, and MTU
C.No default metric is assigned; redistribution fails unless a metric is configured.
D.The OSPF cost is converted to an EIGRP metric using a default formula.
AnswerC

EIGRP does not assign a default metric for redistributed routes; if no metric is specified, the route is not redistributed.

Why this answer

EIGRP requires all five K-values (bandwidth, delay, reliability, load, MTU) for metric calculation, but by default, only bandwidth and delay are used; the default metric for redistribution is not automatically derived and must be explicitly set.

Practice this question →
29
MCQhard

A network engineer is troubleshooting a route redistribution issue between EIGRP and BGP. Router R1 runs both EIGRP and BGP, and redistributes EIGRP routes into BGP. The engineer notices that some EIGRP routes are not appearing in the BGP table on R1. The show ip bgp command does not list these prefixes. The redistribute eigrp command is configured under BGP. What is the most likely cause?

A.The redistribute eigrp command under BGP is missing the subnets keyword.
B.The EIGRP routes are not present in the IP routing table on R1.
C.BGP has a higher administrative distance than EIGRP.
D.The EIGRP process on R1 has a route filter blocking these routes.
AnswerB

Correct: BGP only redistributes routes that are in the routing table; if they are missing, redistribution fails.

Why this answer

When redistributing into BGP, by default only classful networks are redistributed unless the subnets keyword is used. Additionally, BGP does not redistribute routes that are not in the routing table. However, a common cause is that the EIGRP routes are not in the global routing table due to administrative distance or other reasons.

Practice this question →
30
MCQhard

An MPLS network uses OSPF as the IGP. After redistributing BGP routes into OSPF, some LDP neighbors fail to establish. Router R1 config: router ospf 1 redistribute bgp 65001 subnets ! router bgp 65001 redistribute ospf 1 R1# show mpls ldp neighbor Peer LDP Ident: 10.1.1.2:0, Local LDP Ident: 10.1.1.1:0 TCP connection: 10.1.1.2.646 - 10.1.1.1.646 State: Oper, Msg sent: 100, Msg rcvd: 80 Downstream on demand R2# show mpls ldp neighbor Peer LDP Ident: 10.1.1.1:0, Local LDP Ident: 10.1.1.2:0 TCP connection: 10.1.1.1.646 - 10.1.1.2.646 State: Oper, Msg sent: 80, Msg rcvd: 100 What is the root cause?

A.The redistributed BGP routes have a higher administrative distance, causing them to not be installed in the routing table, breaking LDP label binding.
B.The LDP router-id is misconfigured, causing neighbor failure.
C.The OSPF process is missing the mpls ldp autoconfig command.
D.The BGP redistribution is missing the route-map to set the metric.
AnswerA

LDP uses the routing table; if the route is not installed, LDP cannot assign a label.

Why this answer

The redistribution of BGP into OSPF may cause OSPF routes to have a high metric or be external, which LDP may not use for label binding if the route is not in the routing table as an IGP route. LDP requires the route to be in the routing table with a next-hop that is reachable via an IGP. If the redistributed routes have a higher administrative distance or are not installed, LDP may fail to assign labels.

The fix is to ensure that the IGP routes are preferred or use route-target filtering.

Practice this question →
31
MCQhard

An engineer configures unicast Reverse Path Forwarding (uRPF) in strict mode on an interface facing the Internet. Legitimate traffic from a customer network is being dropped. The traffic has a source IP that belongs to the customer's prefix, which is reachable via a different interface on the router. Which is the most likely explanation?

A.The 'ip verify unicast source reachable-via any' command was used instead of 'rx'.
B.The router has a default route pointing out the same interface, causing uRPF to pass all traffic.
C.The customer traffic is arriving on an interface where the return path to the source is via a different interface, violating strict uRPF.
D.The 'ip urpf allow-default' command is missing, causing default routes to be ignored.
AnswerC

Strict uRPF requires symmetric routing; asymmetric routing causes drops.

Why this answer

Strict uRPF checks that the source IP of incoming packets has a route back out the same interface. If the best path to the source IP is via a different interface (asymmetric routing), the packet is dropped. This is a classic edge case with strict uRPF in asymmetric routing scenarios.

Practice this question →
33
MCQhard

A DMVPN network uses EIGRP as the routing protocol. After redistributing a static route into EIGRP on the hub, spoke-to-spoke tunnels fail to form. Hub configuration: router eigrp 100 redistribute static metric 10000 100 255 1 1500 ! ip route 10.0.0.0 255.0.0.0 Null0 Spoke1# show dmvpn Interface: Tunnel0, IPv4 NHRP Details Type:Spoke, NHRP Peers:2, # Ent Peer NBMA Addr Peer Tunnel Addr State UpDn Tm Attrb 1 192.168.1.1 10.1.1.1 UP 00:01:00 D 2 192.168.1.2 10.1.1.2 UP 00:00:30 D What is the root cause?

A.The static Null0 route is redistributed, causing spokes to send traffic to the hub instead of directly to other spokes.
B.The EIGRP metric is too low, causing the route to be preferred over NHRP.
C.The DMVPN tunnel is misconfigured with mismatched authentication.
D.The redistribute static command is missing the route-map to set the next-hop.
AnswerA

The Null0 route blackholes traffic, preventing spoke-to-spoke communication.

Why this answer

The static route to Null0 for 10.0.0.0/8 is redistributed into EIGRP, causing all spokes to learn a summary route pointing to Null0 on the hub. This blackholes traffic destined to other spokes, preventing dynamic spoke-to-spoke tunnel establishment. The fix is to use a more specific static route or filter the Null0 route from redistribution.

Practice this question →
34
MCQmedium

Given this configuration on Router R5: route-map OSPF-to-EIGRP permit 10 match ip address prefix-list EIGRP-ONLY set metric 10000 100 255 1 1500 ! router eigrp 100 redistribute ospf 1 route-map OSPF-to-EIGRP What is the purpose of the route-map in this configuration?

A.The route-map sets the metric for all redistributed OSPF routes, but does not filter any routes.
B.The route-map filters OSPF routes based on the prefix-list and sets the metric for matching routes.
C.The route-map is applied to inbound EIGRP updates, not to redistribution.
D.The route-map will deny all routes because there is no 'permit' statement for the prefix-list.
AnswerB

The match ip address prefix-list filters, and the set metric assigns the metric.

Why this answer

The route-map is used to filter which OSPF routes are redistributed into EIGRP (via the prefix-list) and to set the metric for those routes. Only routes matching the prefix-list will be redistributed.

Practice this question →
35
MCQeasy

When redistributing routes into OSPF, which OSPF metric value is assigned by default if none is specified?

A.1
B.10
C.20
D.100
AnswerC

The default OSPF metric for redistributed routes is 20, as per Cisco IOS default behavior.

Why this answer

Cisco IOS assigns a default metric of 20 to redistributed routes into OSPF, except for BGP routes which default to 1.

Practice this question →
36
MCQhard

Which loop prevention mechanism is used by default when redistributing between two OSPF processes?

A.Split horizon
B.Route tagging with default tag 0
C.Poison reverse
D.Hold-down timers
AnswerB

Route tagging allows an OSPF process to identify and filter routes it originated, preventing loops; the default tag is 0.

Why this answer

When redistributing between OSPF processes, Cisco IOS uses route tagging (tag field in the OSPF external LSA) to prevent loops, but the default tag value is 0 unless explicitly set.

Practice this question →
37
MCQmedium

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# debug ip routing And sees the following output: *Mar 1 00:12:34.567: RT: add 192.168.10.0/24 via 10.1.1.2, ospf metric [110/20] *Mar 1 00:12:34.568: RT: add 192.168.10.0/24 via 10.2.2.2, eigrp metric [90/156160] *Mar 1 00:12:34.569: RT: better route for 192.168.10.0/24 via 10.1.1.2, ospf metric [110/20] *Mar 1 00:12:34.570: RT: add 192.168.10.0/24 to rib via 10.1.1.2, ospf metric [110/20] What does this output indicate?

A.OSPF route is preferred over EIGRP because OSPF has a lower metric.
B.EIGRP route is preferred because it has a lower administrative distance.
C.OSPF route is being installed in the routing table because the EIGRP route may have been withdrawn or not learned.
D.Both routes are installed in the routing table for load balancing.
AnswerC

The debug shows OSPF route being added to RIB. The EIGRP route is considered but not installed, likely because it was withdrawn or not valid. The router compares and selects the OSPF route.

Why this answer

The debug ip routing output shows the routing table process comparing routes from different sources. OSPF has administrative distance 110 and EIGRP has 90, so EIGRP is preferred by default. However, the output shows OSPF being chosen, indicating that the EIGRP route might have been removed or the OSPF route is being redistributed with a lower distance or the EIGRP route is not installed due to other reasons.

Practice this question →
38
MCQhard

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# show ip eigrp topology 192.168.10.0/24 And sees the following output: IP-EIGRP (AS 100): Topology entry for 192.168.10.0/24 State: Passive, Originating, 1 successors, FD is 128256 Routing Descriptor Blocks: 0.0.0.0 (Null0), from 0.0.0.0, Send flag 0x0 Composite metric is (128256/0), Route is Internal Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 5000 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 What does this output indicate?

A.The route 192.168.10.0/24 is learned from an EIGRP neighbor.
B.The route is a summary route configured on this router.
C.The route is redistributed into EIGRP from another protocol, such as OSPF or BGP.
D.The route is a connected interface that is advertised in EIGRP.
AnswerC

The route is in Passive state, originating, with next hop 0.0.0.0, indicating it is locally injected into EIGRP, typically via redistribution.

Why this answer

The show ip eigrp topology command shows a route that is in Passive state and marked as Originating, with the next hop as 0.0.0.0 (Null0). This indicates that the route is a summary route or a redistributed route that is being originated by this router. The metric 128256 and hop count 0 suggest it is a directly connected or redistributed route.

Practice this question →
39
Multi-Selectmedium

Which TWO configuration steps are required to successfully redistribute OSPF routes into EIGRP on a Cisco router? (Choose TWO.)

Select 2 answers
A.Enter EIGRP router configuration mode using the 'router eigrp <as-number>' command.
B.Configure a route-map under OSPF to match OSPF routes for redistribution.
C.Use the 'redistribute eigrp <as-number>' command under OSPF router configuration mode.
D.Set a seed metric for EIGRP using the 'default-metric' command or specify metric in the redistribute command.
E.Issue the 'default-information originate' command under OSPF to advertise redistributed routes.
AnswersA, D

Correct: You must be in EIGRP configuration mode to issue the redistribute command.

Why this answer

To redistribute OSPF into EIGRP, you must enter EIGRP configuration mode and use the redistribute command. Additionally, you must set a seed metric for EIGRP because EIGRP does not have a default metric for redistributed routes. Option A is correct because you need to enter EIGRP router configuration.

Option D is correct because you must set a metric (e.g., bandwidth, delay) for the redistributed routes. Option B is incorrect because you do not need to explicitly match routes in OSPF; you can redistribute all OSPF routes. Option C is incorrect because the redistribute command is under EIGRP, not OSPF.

Option E is incorrect because the default-information originate command is for OSPF to inject a default route, not for redistribution.

Practice this question →
40
Drag & Dropmedium

Drag and drop the steps to verify and validate route redistribution operational state 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

Verification of redistribution starts with checking the routing table for redistributed routes, then examining the specific protocol database, followed by verifying the redistribution configuration, then checking for administrative distance issues, and finally using traceroute to validate the path. This order confirms routes are present, correctly sourced, and reachable.

Practice this question →
41
MCQmedium

Given the following configuration on Router R2: router eigrp 200 redistribute ospf 1 metric 10000 100 255 1 1500 default-metric 10000 100 255 1 1500 What is the effect of having both the 'metric' keyword in the redistribute command and the 'default-metric' command?

A.The 'metric' keyword is ignored; the default-metric is used for all redistributed routes.
B.Both metrics are applied, causing a conflict and potential routing issues.
C.The 'metric' keyword overrides the default-metric for routes redistributed from OSPF into EIGRP.
D.The default-metric command is not needed and can be removed without any effect.
AnswerC

The explicit metric in the redistribute command takes precedence over the default-metric.

Why this answer

The 'metric' keyword in the redistribute command overrides the default-metric for that specific redistribution. The default-metric applies to all other redistribution without an explicit metric.

Practice this question →
42
Multi-Selecthard

An engineer is troubleshooting a route redistribution issue between EIGRP and OSPF. Which TWO actions will prevent routing loops in a mutual redistribution scenario? (Choose TWO.)

Select 2 answers
A.Configure a higher administrative distance for routes learned via redistribution (e.g., distance 200 for OSPF external routes) to prefer the original protocol's routes.
B.Use the 'default-metric' command to set a consistent seed metric for redistributed routes, ensuring all routes have the same metric.
C.Apply route tags to redistributed routes and use distribute lists or route maps to prevent re-redistribution of tagged routes back into the original protocol.
D.Enable 'auto-summary' on both routing protocols to summarize routes at classful boundaries, reducing the number of routes and loop potential.
E.Configure 'passive-interface' on all interfaces where redistribution is performed to prevent routing updates from being sent.
AnswersA, C

Correct. By increasing the administrative distance for redistributed routes, you ensure that the original protocol's routes (with lower AD) are preferred, reducing the chance of a loop where a redistributed route is preferred over the original.

Why this answer

To prevent routing loops during mutual redistribution, you must ensure that routes redistributed from one protocol are not re-injected back into the source protocol. Common methods include setting administrative distance values (e.g., using 'distance' command) or using route tagging with distribute lists or route maps to filter. Simply increasing the metric for redistributed routes does not prevent loops, and disabling auto-summary is unrelated to loop prevention.

Practice this question →
43
MCQmedium

Which statement correctly describes the behavior of the 'default-information originate' command in OSPF?

A.It always injects a default route into OSPF regardless of the routing table.
B.It injects a default route as a Type 3 LSA.
C.It injects a default route as a Type 5 LSA only if a default route exists in the routing table.
D.It injects a default route as a Type 7 LSA in all OSPF areas.
AnswerC

By default, OSPF requires an existing default route to originate a Type 5 LSA for 0.0.0.0/0.

Why this answer

The 'default-information originate' command in OSPF generates a default route (0.0.0.0/0) as a Type 5 LSA, but only if a default route exists in the routing table, unless the 'always' keyword is used.

Practice this question →
44
MCQeasy

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# show ip route summary And sees the following output: Route Source Networks Subnets Replicates Overhead Memory (bytes) connected 2 0 0 0 512 static 1 0 0 0 256 ospf 1 5 0 0 0 1280 eigrp 100 3 0 0 0 768 bgp 65000 2 0 0 0 512 internal 1 0 0 0 256 Total 14 0 0 0 3584 What does this output indicate?

A.The router has 14 routes total, with OSPF contributing the most routes.
B.The router is not redistributing any routes because the counts are low.
C.BGP is the only protocol with external routes.
D.EIGRP has 3 routes, all of which are redistributed from OSPF.
AnswerA

The output shows OSPF has 5 routes, which is the highest count. This indicates OSPF is learning many routes, possibly via redistribution.

Why this answer

The show ip route summary output provides a count of routes from each source. It shows that OSPF has 5 routes, EIGRP has 3, BGP has 2, and static has 1. This can help identify if redistribution is working by comparing expected routes.

Practice this question →
45
MCQhard

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# show ip bgp vpnv4 vrf CUSTOMER routes And sees the following output: Network Next Hop Metric LocPrf Weight Path Route Distinguisher: 100:1 (default for vrf CUSTOMER) *> 192.168.10.0/24 10.1.1.2 0 100 0 65001 i *> 192.168.20.0/24 10.1.1.2 0 100 0 65001 i What does this output indicate?

A.The VRF CUSTOMER has two routes learned via BGP from AS 65001.
B.The routes are redistributed from OSPF into BGP within the VRF.
C.The VRF is not receiving any routes because of a redistribution issue.
D.The routes are locally originated within the VRF.
AnswerA

The output shows two routes with next hop 10.1.1.2 and AS path 65001.

Why this answer

The show ip bgp vpnv4 vrf output shows routes in a VRF. The routes are learned from neighbor 10.1.1.2 with AS path 65001. This indicates that the VRF is receiving routes via BGP, possibly from a PE router.

If redistribution is expected from another protocol into BGP within the VRF, these routes may be the result.

Practice this question →
46
MCQmedium

Which statement correctly describes the behavior of the 'subnets' keyword when redistributing into OSPF?

A.It causes OSPF to redistribute only classful network routes.
B.It allows OSPF to redistribute subnetted routes in addition to classful networks.
C.It changes the metric of redistributed routes to the interface cost.
D.It is required only when redistributing BGP routes into OSPF.
AnswerB

The 'subnets' keyword enables redistribution of routes with subnet masks, ensuring all prefixes are advertised.

Why this answer

Without the 'subnets' keyword, OSPF redistributes only classful network routes; the 'subnets' keyword allows redistribution of subnetted routes, which is essential for proper routing.

Practice this question →
47
MCQhard

An engineer applies a Control Plane Policing (CoPP) policy to a router. After applying, OSPF adjacencies go down. The policy has a class that matches OSPF traffic with a police rate of 1000 pps. The 'show policy-map control-plane' shows no drops. Which is the most likely explanation?

A.The CoPP policy uses 'match protocol ospf' but the router runs OSPFv3, which is not matched by that statement.
B.The police rate is configured in bps instead of pps, causing OSPF hellos to be dropped.
C.The 'class class-default' is configured with a police rate that drops all traffic.
D.The CoPP policy is applied to the input direction, but OSPF packets are sent from the router.
AnswerA

OSPFv3 uses IPv6; 'match protocol ospf' matches OSPFv2 only.

Why this answer

CoPP policies have an implicit 'deny all' at the end. If the OSPF traffic is not matched by any class, it will be dropped by the implicit deny. However, the engineer may have configured a class that matches OSPF but the police rate is in bps, not pps, causing OSPF hellos to be dropped if they exceed the rate.

But the question states no drops, so the issue is likely that the OSPF class is not matching due to incorrect match criteria (e.g., match protocol ospf vs match access-group).

Practice this question →
48
MCQhard

A network engineer configures CoPP to protect the control plane, but after redistributing routes, some legitimate routing updates are dropped. Router R1 config: control-plane service-policy input COPP ! class-map match-all ROUTING match access-group name ROUTING ! policy-map COPP class ROUTING police 100000 15000 15000 conform-action transmit exceed-action drop ! access-list ROUTING permit tcp any any eq bgp access-list ROUTING permit udp any any eq 520 access-list ROUTING permit ospf any any R1# show policy-map control-plane input Class-map: ROUTING (match-all) 100 packets, 10000 bytes 5 minute offered rate 0 bps drop rate 0 bps Match: access-group name ROUTING police: cir 100000 bps, bc 15000 bytes, be 15000 bytes conformed 90 packets, 9000 bytes; actions: transmit exceeded 10 packets, 1000 bytes; actions: drop What is the root cause?

A.The CoPP police rate is too low for the volume of routing updates during redistribution, causing drops.
B.The access-list is missing EIGRP protocol, causing EIGRP packets to be dropped.
C.The class-map is match-all, which requires all conditions to match, but only one ACL is present.
D.The policy-map is applied to the input of the control-plane, but redistribution uses output.
AnswerA

Redistribution generates many routing updates; the police rate is insufficient, leading to drops.

Why this answer

The CoPP policy is policing routing protocol traffic at 100 kbps, which may be insufficient during redistribution bursts. The exceeded drops indicate that some packets are being dropped, likely due to the burst size being too small. The fix is to increase the police rate or burst size to accommodate the redistribution traffic.

Practice this question →
49
MCQmedium

A network engineer runs the following command on Router R1: R1# show ip ospf database external 10.1.1.0 OSPF Router with ID (1.1.1.1) (Process ID 1) Type-5 AS External Link States (Area 0) LS age: 120 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 10.1.1.0 (External Network Number) Advertising Router: 2.2.2.2 LS Seq Number: 80000001 Checksum: 0x1234 Length: 36 Network Mask: /24 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 20 Forward Address: 0.0.0.0 External Route Tag: 100 Based on this output, which statement is correct?

A.The route 10.1.1.0/24 is redistributed into OSPF from another protocol with a route-map setting the tag to 100.
B.The route 10.1.1.0/24 is an OSPF inter-area route from area 0.
C.The metric of 20 indicates the route is redistributed with a default metric of 20, which is correct for Type 1 external routes.
D.The forward address of 0.0.0.0 indicates that the next hop is the advertising router 2.2.2.2.
AnswerA

The External Route Tag of 100 is a common indicator that a route-map was used during redistribution to set the tag.

Why this answer

The output shows an OSPF Type-5 external LSA for 10.1.1.0/24 with Metric Type 2 and Metric 20. The default metric for redistributed routes in OSPF is 20 for Type 2. The External Route Tag of 100 indicates a redistribution tag, often used for filtering or route-maps.

Practice this question →
50
MCQmedium

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# debug ip bgp updates And sees the following output: *Mar 1 00:25:44.789: BGP(0): 10.1.1.2 UPDATE out about 192.168.10.0/24, NEXT_HOP 10.1.1.1, LOCAL_PREF 100, MED 0, origin i, path 65000 65001 *Mar 1 00:25:44.790: BGP(0): 10.1.1.2 UPDATE run, update sent *Mar 1 00:25:44.791: BGP(0): 10.1.1.2 UPDATE in about 10.2.2.0/24, NEXT_HOP 10.1.1.2, LOCAL_PREF 100, MED 0, origin i, path 65002 What does this output indicate?

A.BGP is redistributing routes from OSPF into BGP, as shown by the AS path.
B.R1 is advertising 192.168.10.0/24 to neighbor 10.1.1.2 and learning 10.2.2.0/24 from the same neighbor.
C.The route 192.168.10.0/24 is being filtered due to AS path length.
D.BGP is not receiving any routes because of a redistribution issue.
AnswerB

The output shows outbound update for 192.168.10.0/24 and inbound update for 10.2.2.0/24, indicating BGP peering is working.

Why this answer

The debug ip bgp updates output shows BGP updates being sent and received. R1 sends an update for 192.168.10.0/24 with AS path 65000 65001 and receives an update for 10.2.2.0/24 with AS path 65002. This indicates BGP is exchanging routes, but if redistribution is expected, the AS path may indicate the route origin.

Practice this question →
51
Multi-Selecthard

Which TWO statements are true regarding the use of route maps for route redistribution? (Choose TWO.)

Select 3 answers
A.A route map used in redistribution can match on a prefix list to selectively redistribute only specific networks.
B.If a route map is applied to a redistribution command and no 'permit' statement matches, all routes are denied by default.
C.The 'set metric' command within a route map can only be used to increase the metric of redistributed routes, not decrease it.
D.Route maps can change the administrative distance of redistributed routes by using the 'set distance' command.
E.Route maps can match on the route tag using the 'match tag' command, allowing filtering based on manually assigned tags.
AnswersA, B, E

Correct. Route maps can use 'match ip address prefix-list' to filter routes based on prefix lists, allowing selective redistribution.

Why this answer

Route maps in redistribution allow granular control. They can match on various attributes like prefix lists, tags, or metrics. The 'set' command can modify metrics or tags.

However, route maps do not automatically permit all routes; a 'permit' statement is required for routes to be redistributed. Also, route maps cannot change the administrative distance of redistributed routes; that is done with the 'distance' command.

Practice this question →
52
MCQmedium

A network engineer runs the following command on Router R1: R1# show ip eigrp interfaces detail GigabitEthernet0/1 IP-EIGRP interfaces for process 100 Xmit Queue Mean Pacing Time Multicast Pending Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes Gi0/1 1 0/0 10 0/10 50 0 Hello interval is 5 sec Next xmit serial <none> Un/reliable mcasts: 0/0 Un/reliable ucasts: 0/0 Mcast exceptions: 0 CR packets: 0 ACKs suppressed: 0 Retransmissions: 0 Out of sequence: 0 Authentication mode: none Redistribution: redistributed Based on this output, what is the problem?

A.The interface is configured for redistribution, which is correct for EIGRP.
B.The 'redistributed' flag indicates that routes are being redistributed into EIGRP on this interface, which is not a standard EIGRP feature.
C.The interface has one EIGRP neighbor, and redistribution is working correctly.
D.The output shows that redistribution is enabled, but the interface is not sending hellos.
AnswerB

EIGRP does not have per-interface redistribution; this output is likely from a different context or a misinterpretation.

Why this answer

The output shows 'Redistribution: redistributed' under the interface details, indicating that redistribution is enabled on this interface. However, this is not a standard field in 'show ip eigrp interfaces detail' output; it is likely a custom or misinterpreted output. The problem is that redistribution is applied per interface, but EIGRP redistribution is a global process, not interface-specific.

This could cause confusion or misconfiguration.

Practice this question →
53
MCQhard

An engineer configures IPsec site-to-site VPN between two routers. The tunnel establishes, but traffic does not pass. The 'show crypto ipsec sa' shows packets being encapsulated but no decapsulation. Which is the most likely explanation?

A.The transform set on the remote peer is missing ESP encryption.
B.The crypto ACL on the local router permits traffic, but the remote router's crypto ACL does not match the decrypted traffic.
C.The IKE policy uses aggressive mode, which is incompatible with main mode.
D.The 'crypto isakmp key' command uses a different pre-shared key on each side.
AnswerB

Mismatched interesting traffic ACLs cause the remote peer to not recognize the traffic as IPsec-protected.

Why this answer

If packets are encapsulated but not decapsulated, the remote peer is likely not receiving the encrypted traffic or cannot decrypt it. A common edge case is that the interesting traffic ACL on one side does not match the actual traffic (e.g., mismatched source/destination), causing the remote peer to receive packets that do not match its crypto map ACL, so it drops them.

Practice this question →
54
MCQmedium

A network engineer runs the following command on Router R1: R1# show ip eigrp topology 10.1.1.0/24 IP-EIGRP (AS 100): Topology entry for 10.1.1.0/24 State: Passive, Originating reply status: 0 Routing Descriptor Blocks: 0.0.0.0 (Null0), from 0.0.0.0, Send flag: 0x0 Composite metric is (2560000000/0), Route is Internal Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 0 10.2.2.2 (GigabitEthernet0/1), from 10.2.2.2, Send flag: 0x0 Composite metric is (2688000000/2560000000), Route is Internal Vector metric: Minimum bandwidth is 100000 Kbit Total delay is 200 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1 Based on this output, what is the problem?

A.The route 10.1.1.0/24 is redistributed from another protocol into EIGRP.
B.A manual summary route is configured on R1 for 10.1.1.0/24, causing a local Null0 entry.
C.The route 10.1.1.0/24 is flapping between Passive and Active states.
D.The neighbor 10.2.2.2 is not reachable, so the route is installed via Null0.
AnswerB

The Null0 entry with metric 2560000000/0 indicates a summary route; the 'ip summary-address eigrp' command creates this entry to prevent loops.

Why this answer

The output shows a Null0 entry with a metric of 2560000000/0, which is characteristic of a summary route. The problem is that an EIGRP summary route is being advertised, but the route is also learned from another neighbor (10.2.2.2) with a higher metric, indicating potential suboptimal routing or a missing 'no auto-summary' command.

Practice this question →
55
MCQhard

A network engineer configures redistribution between OSPF and EIGRP on a multi-access link. After configuration, OSPF neighbors keep flapping. Router R1 config: interface GigabitEthernet0/0 ip ospf network broadcast ip ospf hello-interval 10 ! router ospf 1 redistribute eigrp 100 subnets ! router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 R1# show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 192.168.1.2 1 FULL/DR 00:00:35 10.1.1.2 GigabitEthernet0/0 192.168.1.3 1 2WAY/DROTHER 00:00:31 10.1.1.3 GigabitEthernet0/0 What is the root cause?

A.The OSPF hello interval is too low, causing neighbor flapping under load from redistribution.
B.The EIGRP metric is misconfigured, causing route inconsistency.
C.The OSPF network type broadcast requires a DR/BDR election, causing instability.
D.The redistribute command under OSPF is missing the metric type.
AnswerA

Redistribution increases CPU load, causing hello packets to be delayed and neighbors to time out.

Why this answer

The OSPF network type is broadcast, but the EIGRP redistribution may be causing OSPF LSAs to be flooded with high CPU load, leading to neighbor flapping. Additionally, the hello interval is set to 10 seconds, but the dead interval is not explicitly set, defaulting to 40 seconds. If the router is overloaded, hello packets may be missed.

The fix is to increase the dead interval or adjust the network type to point-to-point.

Practice this question →
56
MCQhard

What is the default metric value assigned to redistributed routes into IS-IS when no metric is specified?

A.0
B.10
C.20
D.63
AnswerA

IS-IS uses a default metric of 0 for redistributed routes, requiring manual configuration to set a meaningful metric.

Why this answer

By default, Cisco IOS assigns a metric of 0 to routes redistributed into IS-IS, which can cause suboptimal routing if not modified.

Practice this question →
57
MCQhard

A network engineer is troubleshooting a route redistribution issue between two OSPF processes. Router R1 runs OSPF process 1 and OSPF process 2, and redistributes routes between them. The engineer notices that routes from OSPF process 1 are not appearing in the OSPF database of process 2, even though the redistribute command is configured. The show ip ospf database command on R1 for process 2 shows no external routes. What is the most likely cause?

A.The redistribute ospf 1 command under OSPF process 2 is missing the subnets keyword.
B.OSPF process 1 has a higher administrative distance than OSPF process 2.
C.The redistribute ospf 1 command under OSPF process 2 is missing the match internal keyword.
D.OSPF process 2 has a route map applied that is filtering all routes.
AnswerA

Correct: Without subnets, only classful networks are redistributed, causing many missing routes.

Why this answer

When redistributing between OSPF processes, the redistribute command must include the subnets keyword to redistribute classless subnets. Without it, only classful networks are redistributed, which may cause many routes to be missing.

Practice this question →
58
MCQhard

A large enterprise network is experiencing intermittent reachability to a subnet 10.1.1.0/24 from the rest of the network. Router R1 has the following relevant configuration: router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 ! router ospf 1 redistribute eigrp 100 subnets summary-address 10.0.0.0 255.255.0.0 ! interface GigabitEthernet0/0 ip summary-address eigrp 100 10.0.0.0 255.255.0.0 5 Router R2 shows: R2# show ip route 10.1.1.0 Routing entry for 10.0.0.0/16, supernet Known via "eigrp 100", distance 90, metric 128256 Redistributing via eigrp 100 Last update from 10.10.10.1 on GigabitEthernet0/1 What is the root cause?

A.The OSPF summary-address command on R1 is blocking the redistribution of the specific /24 route.
B.The EIGRP metric values are too high, causing the route to be unreachable.
C.The redistribute ospf command under EIGRP is missing the subnets keyword.
D.The route is being filtered by a distribute-list on R2.
AnswerA

The OSPF summary-address creates an aggregate route, and combined with the EIGRP interface summary, the specific /24 is suppressed.

Why this answer

The issue is that R1 has both an OSPF summary-address and an EIGRP interface summary-address, causing the more specific /24 route to be suppressed by the /16 summary. The EIGRP summary-address command on the interface creates a null0 summary route, and the OSPF redistribution of the EIGRP summary further aggregates, losing the specific prefix. The fix is to remove the interface summary-address or adjust the summary to include the specific subnet.

Practice this question →
59
Multi-Selectmedium

Which TWO statements about route redistribution between EIGRP and OSPF are true? (Choose TWO.)

Select 2 answers
A.When redistributing EIGRP into OSPF, the OSPF metric must be explicitly configured if the default metric of 20 is not desired.
B.When redistributing OSPF into EIGRP, the default EIGRP metric is 1.
C.When redistributing OSPF into EIGRP, the default EIGRP metric is 100.
D.When redistributing OSPF into EIGRP, a seed metric must be configured for EIGRP to advertise the redistributed routes.
E.Route-maps cannot be used to filter routes during redistribution between EIGRP and OSPF.
AnswersA, D

Correct: OSPF uses a default metric of 20 for redistributed routes, so explicit configuration is needed to change it.

Why this answer

When redistributing between EIGRP and OSPF, the seed metric must be explicitly set for the receiving protocol. EIGRP uses a composite metric (bandwidth, delay, reliability, load, MTU) and OSPF uses a metric of type 1 or type 2. By default, OSPF assigns a metric of 20 to redistributed routes unless specified otherwise.

Option A is correct because OSPF requires a seed metric for redistributed routes. Option D is correct because EIGRP redistributed routes default to an infinite metric (effectively not advertised) unless a seed metric is provided. Option B is incorrect because OSPF default metric is 20, not 1.

Option C is incorrect because the default metric for EIGRP is not 100. Option E is incorrect because route-maps can be used to filter redistributed routes.

Practice this question →
60
MCQmedium

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# show ip ospf database external And sees the following output: OSPF Router with ID (1.1.1.1) (Process ID 1) Type-5 AS External Link States LS age: 360 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 192.168.10.0 (External Network Number ) Advertising Router: 2.2.2.2 LS Seq Number: 80000001 Checksum: 0x1234 Length: 36 Network Mask: /24 Metric Type: 2 (Larger than any link state path) TOS: 0 Metric: 20 Forward Address: 0.0.0.0 External Route Tag: 100 What does this output indicate?

A.The route 192.168.10.0/24 is an OSPF internal route.
B.The route is redistributed into OSPF with a metric of 20 and a route tag of 100.
C.The forward address is 0.0.0.0, meaning the route is not reachable.
D.The route is a default route redistributed into OSPF.
AnswerB

The LSA shows metric type 2, metric 20, and tag 100, typical for redistributed routes.

Why this answer

The show ip ospf database external output shows a Type 5 LSA for 192.168.10.0/24, with metric type 2 and metric 20, and external route tag 100. This indicates that the route is redistributed into OSPF from another protocol (likely EIGRP or BGP) by router 2.2.2.2. The tag 100 can be used for filtering.

Practice this question →
61
MCQmedium

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# debug eigrp packets And sees the following output: *Mar 1 00:15:22.123: EIGRP: Received UPDATE on Serial0/0/0 nbr 10.1.1.2 *Mar 1 00:15:22.124: AS 100, Flags 0x1, Seq 45/0 idbQ 0/0 iidbQ un/rely 0/0 *Mar 1 00:15:22.125: Ext: 192.168.10.0/255.255.255.0, metric 156160, tag 0 *Mar 1 00:15:22.126: EIGRP: Enqueueing UPDATE on Serial0/0/0 nbr 10.1.1.2 iidbQ un/rely 0/1 peerQ un/rely 0/0 serno 12-12 *Mar 1 00:15:22.127: EIGRP: Sending UPDATE on Serial0/0/0 nbr 10.1.1.2, retry 0, R=1 *Mar 1 00:15:22.128: Ext: 10.2.2.0/255.255.255.0, metric 128256, tag 0 What does this output indicate?

A.EIGRP is redistributing routes from another protocol into EIGRP, as indicated by the tag 0.
B.R1 is learning 192.168.10.0/24 via EIGRP and advertising 10.2.2.0/24 back to the same neighbor, which could indicate a routing loop.
C.R1 is receiving an EIGRP update and sending an update in response, which is normal EIGRP behavior.
D.The metric of 156160 indicates that the route 192.168.10.0/24 is redistributed from OSPF.
AnswerC

The output shows standard EIGRP update exchange. No redistribution issue is visible.

Why this answer

The debug eigrp packets output shows EIGRP update packets being exchanged. R1 receives an update for 192.168.10.0/24 from neighbor 10.1.1.2 and then sends an update for 10.2.2.0/24. This indicates normal EIGRP operation; no redistribution issue is apparent from this output.

Practice this question →
62
MCQmedium

A network engineer is troubleshooting a route redistribution issue between EIGRP and OSPF. Routers R1 (EIGRP) and R2 (OSPF) are redistributing routes. The engineer notices that some EIGRP routes are appearing in the OSPF database on R2, but traffic to those destinations is not being forwarded correctly. The show ip route command on R2 shows the redistributed routes with a next-hop of 0.0.0.0. What is the most likely cause?

A.The redistribute eigrp command under OSPF is missing the subnets keyword.
B.The OSPF process on R2 has a route map that is changing the next-hop.
C.EIGRP has a lower administrative distance than OSPF.
D.The EIGRP routes are not in the routing table on R2.
AnswerA

Correct: Without subnets, the next-hop may be set to 0.0.0.0 for classless routes.

Why this answer

When redistributing into OSPF, if the redistributed routes are not directly connected to the redistributing router, the next-hop may be set to 0.0.0.0 (self) if the subnets keyword is missing or if the route is not in the routing table. However, a common cause is that the redistribute command is missing the subnets keyword, causing classful behavior.

Practice this question →
63
MCQeasy

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# debug ip ospf adj And sees the following output: *Mar 1 00:20:11.456: OSPF: Rcv pkt from 10.1.1.2, Serial0/0/0 : Mismatch Authentication type. Input packet specified type 0, we use type 1 *Mar 1 00:20:11.457: OSPF: Rcv pkt from 10.1.1.2, Serial0/0/0 : Mismatch Authentication type. Input packet specified type 0, we use type 1 What does this output indicate?

A.OSPF adjacency is forming successfully with authentication.
B.OSPF authentication is misconfigured; the neighbor is not using authentication while this router is.
C.OSPF is redistributing routes correctly but authentication is failing.
D.The OSPF process is using MD5 authentication and the neighbor is using plaintext.
AnswerB

The router expects authentication type 1, but the neighbor sends type 0, indicating a configuration mismatch.

Why this answer

The debug ip ospf adj output shows authentication type mismatch. The router expects type 1 (plaintext authentication) but the received packet has type 0 (no authentication). This prevents the OSPF adjacency from forming, which would affect route redistribution if OSPF is not learning routes.

Practice this question →
64
MCQhard

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.
B.The EIGRP neighbor is stuck-in-active because a query was sent but no reply was received due to a unidirectional link.
C.The OSPF routes are external type 2, which are not redistributed by default.
D.The 'route-map' used for redistribution has a 'match ip address' that does not match the OSPF routes.
AnswerB

Active state indicates a query is outstanding, often due to a unidirectional link.

Why this answer

When redistributing into EIGRP, a seed metric must be specified. If not, the routes are redistributed with an infinite metric (e.g., 4294967295) and are not installed. However, the question says the route is in active state, which indicates a query is pending.

This is an edge case where the route is redistributed with a valid metric but the EIGRP process is stuck-in-active due to a unidirectional link or a neighbor not replying to queries.

Practice this question →
65
MCQhard

A network engineer runs the following command to troubleshoot a Route Redistribution issue: R1# show bgp ipv4 unicast 192.168.10.0/24 And sees the following output: BGP routing table entry for 192.168.10.0/24, version 2 Paths: (1 available, best #1, table default) Advertised to update-groups: 1 Refresh Epoch 1 Local 0.0.0.0 from 0.0.0.0 (1.1.1.1) Origin incomplete, metric 0, localpref 100, weight 32768, valid, sourced, best rx pathid: 0, tx pathid: 0x0 What does this output indicate?

A.The route 192.168.10.0/24 is learned from an EBGP neighbor.
B.The route is injected into BGP via the network command, as shown by origin incomplete.
C.The route is redistributed into BGP from another protocol, as indicated by origin incomplete and weight 32768.
D.The route is a default route injected into BGP.
AnswerC

Origin incomplete and weight 32768 are typical for redistributed routes.

Why this answer

The show bgp ipv4 unicast output shows a route with next hop 0.0.0.0, origin incomplete, and weight 32768. This indicates the route is locally originated, likely via redistribution or network command. Origin incomplete (incomplete) suggests the route was redistributed from another protocol.

Practice this question →
66
Drag & Dropmedium

Drag and drop the steps to perform mutual redistribution between OSPF and EIGRP 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 route filtering is applied before redistribution to prevent routing loops, and that redistribution is configured on both protocols symmetrically. First, identify the routing domains and interfaces. Second, configure route filtering using distribute-lists or route-maps to control which routes are exchanged.

Third, configure redistribution of EIGRP into OSPF. Fourth, configure redistribution of OSPF into EIGRP. Finally, verify the redistribution using show commands to confirm routes are exchanged correctly.

Practice this question →
67
MCQhard

A network engineer runs the following command on Router R1: R1# show route-map REDISTRIBUTE route-map REDISTRIBUTE, permit, sequence 10 Match clauses: ip address prefix-list EIGRP_ROUTES Set clauses: metric 100 metric-type type-1 tag 200 Policy routing matches: 0 packets, 0 bytes route-map REDISTRIBUTE, deny, sequence 20 Match clauses: ip address prefix-list DENY_ALL Set clauses: Policy routing matches: 0 packets, 0 bytes Based on this output, what is the problem?

A.The route-map will redistribute all routes that match prefix-list EIGRP_ROUTES with metric 100 and type-1.
B.The route-map has a deny sequence that may block all routes if prefix-list DENY_ALL is configured to permit all.
C.The route-map will only redistribute routes with tag 200.
D.The route-map is not applied to any redistribution command, so it has no effect.
AnswerB

If DENY_ALL is a catch-all prefix-list (e.g., permit 0.0.0.0/0 le 32), then sequence 20 will deny all routes, overriding sequence 10.

Why this answer

The route-map has a deny sequence 20 that matches prefix-list DENY_ALL. If DENY_ALL is configured to permit all (e.g., permit 0.0.0.0/0 le 32), then all routes will be denied after sequence 10, effectively blocking redistribution. The problem is that the deny sequence may unintentionally block routes that should be redistributed.

Practice this question →
68
MCQmedium

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.
B.EIGRP AS 100 has a higher administrative distance than EIGRP AS 200.
C.The redistribute eigrp 100 command under EIGRP AS 200 is missing the subnets keyword.
D.EIGRP AS 200 has a route map that is filtering all routes.
AnswerA

Correct: Without a metric, EIGRP does not accept redistributed routes.

Why this answer

When redistributing between EIGRP processes, the redistribute command must include the metric values (bandwidth, delay, reliability, load, MTU) or a default-metric must be configured. Without a metric, the redistributed routes are not accepted.

Practice this question →
69
MCQmedium

What is the default administrative distance for routes redistributed into EIGRP from another protocol?

A.90
B.110
C.170
D.200
AnswerC

Cisco IOS assigns a default administrative distance of 170 to all routes redistributed into EIGRP, matching the distance of external EIGRP routes.

Why this answer

By default, EIGRP assigns an administrative distance of 170 to routes learned via redistribution, distinguishing them from internal EIGRP routes (AD 90) and external EIGRP routes (AD 170).

Practice this question →
70
Multi-Selecthard

An engineer is redistributing OSPF routes into EIGRP. Which TWO commands can be used to verify that the redistribution is working correctly? (Choose TWO.)

Select 2 answers
A.show ip route eigrp
B.show ip eigrp topology
C.show ip ospf database
D.show ip protocols
E.show ip route ospf
AnswersA, B

Correct. This command displays EIGRP routes in the routing table. If OSPF routes are successfully redistributed into EIGRP, they will appear as EIGRP routes (usually marked with 'D EX' for external).

Why this answer

To verify redistribution, you can check the routing table of the receiving protocol (EIGRP) to see if the redistributed routes appear. Additionally, 'show ip eigrp topology' shows the EIGRP topology table, which includes redistributed routes. 'show ip ospf database' is for OSPF LSDB and does not show redistributed routes into EIGRP. 'show ip protocols' shows redistribution configuration but not active routes. 'show ip route eigrp' shows only EIGRP routes, but if redistribution is working, those routes should appear there.

Practice this question →
71
MCQhard

A network engineer configures OSPF on two routers connected via Ethernet. The adjacency forms but remains stuck in EXSTART state. Both routers have identical OSPF configuration except for MTU. Which is the most likely explanation?

A.The OSPF network type is point-to-point on one side and broadcast on the other.
B.The MTU on the interfaces is mismatched, causing DBD packet rejection.
C.The OSPF router ID is identical on both routers.
D.The 'ip ospf authentication' is configured only on one side.
AnswerB

MTU mismatch is a classic cause of EXSTART state.

Why this answer

OSPF uses the interface MTU in Database Description (DBD) packets. If MTU values differ, the neighbor will reject DBD packets larger than its own MTU, causing the adjacency to stall in EXSTART. The fix is to use 'ip ospf mtu-ignore' or match MTU.

Practice this question →
72
MCQhard

A network engineer notices that after redistributing EIGRP into OSPF, a routing loop occurs between two routers. Router R1 config: router ospf 1 redistribute eigrp 100 subnets ! router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 R1# show ip route 192.168.1.0 Routing entry for 192.168.1.0/24 Known via "eigrp 100", distance 90, metric 128256 Redistributing via eigrp 100 Last update from 10.1.1.2 on GigabitEthernet0/0 R2# show ip route 192.168.1.0 Routing entry for 192.168.1.0/24 Known via "ospf 1", distance 110, metric 20 Redistributing via ospf 1 Last update from 10.1.1.1 on GigabitEthernet0/0 What is the root cause?

A.The redistribute commands are missing route-map filters, causing mutual redistribution and a loop.
B.The EIGRP metric is too low, causing OSPF to prefer the redistributed route.
C.The OSPF administrative distance is higher than EIGRP, causing suboptimal path selection.
D.The subnets keyword under OSPF redistribution is causing classful behavior.
AnswerA

Without filtering, routes learned from one protocol are redistributed back, creating a loop.

Why this answer

Mutual redistribution between EIGRP and OSPF without route filtering causes a routing loop. R1 learns the route via EIGRP and redistributes into OSPF; R2 learns via OSPF and redistributes back into EIGRP, creating a loop. The fix is to use route-maps to filter redistributed routes or set administrative distance to prefer one source.

Practice this question →
73
MCQhard

An enterprise uses BGP to exchange routes with a service provider. After redistributing OSPF into BGP, some prefixes are missing. Router R1 config: router bgp 65001 redistribute ospf 1 match internal external 1 external 2 ! router ospf 1 redistribute bgp 65001 subnets R1# show ip bgp 10.10.10.0 % Network not in table R1# show ip ospf database external 10.10.10.0 Type-5 AS External Link States LS age: 360 Options: (No TOS-capability, DC) LS Type: AS External Link Link State ID: 10.10.10.0 (External Network Number) Advertising Router: 192.168.1.2 LS Seq Number: 80000001 Checksum: 0x1234 Length: 36 Network Mask: /24 Metric Type: 2 (Larger than any link state path) Metric: 20 Forward Address: 0.0.0.0 External Route Tag: 0 What is the root cause?

A.The OSPF external route is not installed in the routing table because of a mismatched metric type or LSA filtering.
B.The BGP redistribute command is missing the route-map to set the metric.
C.The OSPF process is not configured with the default-information originate command.
D.The BGP table is full and cannot accept more routes.
AnswerA

The route appears in the database but not in the routing table, so BGP cannot redistribute it.

Why this answer

The OSPF external route 10.10.10.0/24 has a Forward Address of 0.0.0.0, which means it is reachable via the advertising router. However, BGP redistribution of OSPF requires the route to be in the OSPF routing table, not just the database. The route may be missing due to an OSPF LSA filtering or a mismatched area.

The correct fix is to ensure the OSPF route is fully installed and not filtered.

Practice this question →
74
MCQhard

Consider the following configuration on Router R4: router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500 router ospf 1 redistribute eigrp 100 metric 20 metric-type 1 subnets What is a potential issue with this configuration?

A.The configuration is correct and will work without issues.
B.The 'metric-type 1' in OSPF redistribution may cause EIGRP routes to be preferred over OSPF routes.
C.Mutual redistribution without route filtering can cause routing loops or suboptimal routing.
D.The EIGRP metric values are invalid because load must be between 1 and 255.
AnswerC

Without filtering, routes can be redistributed back and forth, causing loops.

Why this answer

Mutual redistribution without route filtering or administrative distance adjustments can cause routing loops or suboptimal routing. The configuration does not include any route-maps or distribute-lists to control which routes are redistributed, which is a common pitfall.

Practice this question →
75
MCQmedium

A network engineer runs the following command on Router R1: R1# show ip route 10.1.1.0 Routing entry for 10.1.1.0/24 Known via "eigrp 100", distance 170, metric 2560000 Redistributing via eigrp 100 Advertised by eigrp 100 (self originated) Last update from 10.2.2.2 on GigabitEthernet0/1, 00:00:10 ago Routing Descriptor Blocks: * 10.2.2.2, from 10.2.2.2, 00:00:10 ago, via GigabitEthernet0/1 Route metric is 2560000, traffic share count is 1 Total delay is 100 microseconds, minimum bandwidth is 100000 Kbit Reliability 255/255, minimum MTU 1500 Loading 1/255, Hops 1 Based on this output, what is the problem?

A.The route 10.1.1.0/24 is an internal EIGRP route because the administrative distance is 90.
B.The route is redistributed into EIGRP from another protocol, as indicated by the distance of 170 and the 'self originated' message.
C.The route is learned from a neighbor with a metric of 2560000, which is the default for redistributed routes.
D.The route is not being advertised to any EIGRP neighbors because it is marked as 'self originated'.
AnswerB

The distance of 170 and the 'self originated' flag indicate redistribution into EIGRP.

Why this answer

The output shows a route learned via EIGRP with an administrative distance of 170, which is the default for external EIGRP routes. The route is marked as 'Redistributing via eigrp 100' and 'Advertised by eigrp 100 (self originated)', indicating that this route was redistributed into EIGRP from another protocol. The problem is that the route is both learned and redistributed by the same router, which could cause a routing loop if not filtered.

Practice this question →
Page 1 of 2 · 76 questions totalNext →

Ready to test yourself?

Try a timed practice session using only Route Redistribution questions.

Start 20-question session