300-410 Route Redistribution Practice Test 2 — 15 Questions

Question 1

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?

Accepted Answer

The routes are not being advertised to eBGP peers because the next hop is 0.0.0.0, which is invalid for eBGP.. 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.

Answer

The routes are correctly advertised with next hop 0.0.0.0, which is normal for locally originated routes.

Answer

The routes are being advertised to iBGP peers only, as indicated by the next hop 0.0.0.0.

Answer

The routes are redistributed from an IGP into BGP, and the next hop is correctly set to 0.0.0.0.

Question 2

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?

Accepted Answer

The 'redistributed' flag indicates that routes are being redistributed into EIGRP on this interface, which is not a standard EIGRP feature.. 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.

Answer

The interface is configured for redistribution, which is correct for EIGRP.

Answer

The interface has one EIGRP neighbor, and redistribution is working correctly.

Answer

The output shows that redistribution is enabled, but the interface is not sending hellos.

Question 3

A network engineer runs the following command on Router R1:

R1# show ip route 192.168.1.0
Routing entry for 192.168.1.0/24
  Known via "ospf 1", distance 110, metric 20, type extern 2, forward metric 100
  Redistributing via ospf 1
  Last update from 10.1.1.2 on GigabitEthernet0/1, 00:00:05 ago
  Routing Descriptor Blocks:
  * 10.1.1.2, from 10.1.1.2, 00:00:05 ago, via GigabitEthernet0/1
      Route metric is 20, traffic share count is 1

Based on this output, what is the problem?

Accepted Answer

The route is being redistributed back into OSPF, which could cause a routing loop if not filtered.. The output shows a route learned via OSPF with type extern 2 and metric 20. The route is also 'Redistributing via ospf 1', meaning this router is redistributing this route back into OSPF. This could cause a routing loop if the route is redistributed back into the same OSPF process from which it was learned. The problem is that the route is being redistributed without filtering, potentially causing loops.

Answer

The route is an external OSPF route with metric 20, which is the default for Type 2 external routes.

Answer

The forward metric is 100, which is the metric to the ASBR.

Answer

The route is learned from neighbor 10.1.1.2, which is the next hop.

Question 4

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?

Accepted Answer

Redistributed OSPF routes into EIGRP will have a default metric of 10000 100 255 1 1500.. 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.

Answer

OSPF routes redistributed into EIGRP will have a metric of 20 by default.

Answer

EIGRP routes redistributed into OSPF will be Type 1 external LSAs.

Answer

The 'subnets' keyword in OSPF redistribution is optional but recommended.

Question 5

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?

Accepted Answer

The 'metric' keyword overrides the default-metric for routes redistributed from OSPF into EIGRP.. 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.

Answer

The 'metric' keyword is ignored; the default-metric is used for all redistributed routes.

Answer

Both metrics are applied, causing a conflict and potential routing issues.

Answer

The default-metric command is not needed and can be removed without any effect.

Question 6

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?

Accepted Answer

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.. 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.

Answer

Redistributed RIP routes become OSPF Type 2 external LSAs with a fixed metric of 50.

Answer

The 'metric-type 1' is ignored because the 'metric' keyword is also used.

Answer

The redistributed routes will have a metric of 50 and will not be affected by internal OSPF cost.

Question 7

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?

Accepted Answer

Mutual redistribution without route filtering can cause routing loops or suboptimal routing.. 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.

Answer

The configuration is correct and will work without issues.

Answer

The 'metric-type 1' in OSPF redistribution may cause EIGRP routes to be preferred over OSPF routes.

Answer

The EIGRP metric values are invalid because load must be between 1 and 255.

Question 8

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?

Accepted Answer

The route-map filters OSPF routes based on the prefix-list and sets the metric for matching routes.. 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.

Answer

The route-map sets the metric for all redistributed OSPF routes, but does not filter any routes.

Answer

The route-map is applied to inbound EIGRP updates, not to redistribution.

Answer

The route-map will deny all routes because there is no 'permit' statement for the prefix-list.

Question 9

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?

Accepted Answer

The router will advertise a default route into OSPF even if it does not have a default route itself, potentially causing blackholing.. 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.

Answer

The 'default-information originate always' command is not allowed with redistribution.

Answer

The 'subnets' keyword is missing for EIGRP redistribution.

Answer

The redistribution will only work if EIGRP routes have a metric set.

Question 10

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

Accepted Answer

20. 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.

Answer

1

Answer

10

Answer

0

Question 11

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

Accepted Answer

K5 (MTU). 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.

Answer

K1 (bandwidth)

Answer

K3 (delay)

Answer

K2 (load)

Question 12

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

Accepted Answer

Apply route filtering using route-maps or prefix-lists to control which routes are redistributed.. 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.

Answer

Use the same administrative distance for both protocols.

Answer

Increase the default metric to a high value to discourage redistribution.

Answer

Disable route summarization on both protocols.

Question 13

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

Accepted Answer

When redistributing EIGRP into OSPF, the OSPF metric must be explicitly configured if the default metric of 20 is not desired.. 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.

Answer

When redistributing OSPF into EIGRP, the default EIGRP metric is 1.

Answer

When redistributing OSPF into EIGRP, the default EIGRP metric is 100.

Answer

Route-maps cannot be used to filter routes during redistribution between EIGRP and OSPF.

Question 14

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

Accepted Answer

Routing loops occur where packets traverse multiple routers repeatedly.. 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.

Answer

CPU utilization on the redistribution router is consistently below 50%.

Answer

The routing table on all routers is stable and converges quickly after a topology change.

Question 15

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

Accepted Answer

Enter EIGRP router configuration mode using the 'router eigrp <as-number>' command.. 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.

Answer

Configure a route-map under OSPF to match OSPF routes for redistribution.

Answer

Use the 'redistribute eigrp <as-number>' command under OSPF router configuration mode.

Answer

Issue the 'default-information originate' command under OSPF to advertise redistributed routes.