300-410 Route Summarization Practice Test 4 — 15 Questions

Question 1

A network engineer runs the following command to troubleshoot a Route Summarization issue:

R1# show ip route summary
IP routing table maximum-paths limit: 32
IP routing table entry count: 15
IP routing table active entry count: 15
Number of prefixes: 15
Number of /0: 0
Number of /8: 1
Number of /16: 2
Number of /24: 12
Number of /32: 0

What does this output indicate?

Accepted Answer

The routing table contains 2 /16 summary routes, likely summarizing the 12 /24 subnets, indicating successful route summarization.. This output shows a summary of the IP routing table. The prefix length distribution indicates that there are 2 /16 routes and 12 /24 routes. This suggests that route summarization is in effect, as the /16 routes likely summarize the /24 subnets.

Answer

The routing table has no summarization, as all routes are /24 or smaller.

Answer

The routing table is full and cannot accept more routes.

Answer

The summary routes are not being used because they are inactive.

Question 2

A network engineer runs the following command to troubleshoot a Route Summarization issue:

R1# debug ip routing
IP: route table change: 10.0.0.0/16 via 10.1.1.2, Serial0/0/0, distance 90, metric 128576
IP: route table change: 10.0.1.0/24 via 10.1.1.2, Serial0/0/0, distance 90, metric 128576
IP: route table change: 10.0.2.0/24 via 10.1.1.2, Serial0/0/0, distance 90, metric 128576

What does this output indicate?

Accepted Answer

Both the summary route 10.0.0.0/16 and more specific /24 routes are being installed, which could indicate that summarization is not properly filtering the specific routes.. The debug output shows that multiple routes (a /16 and two /24s) are being installed into the routing table via the same next hop. This indicates that both the summary route and more specific routes are present, which may be a sign of inconsistent summarization or a leak of more specific routes.

Answer

Only the summary route is being installed, and the /24 routes are being ignored.

Answer

The summary route is being replaced by the more specific routes.

Answer

The routes are being learned via different routing protocols.

Question 3

A network engineer runs the following command to troubleshoot a Route Summarization issue:

R1# show mpls ldp bindings 10.0.0.0/16
  tib entry: 10.0.0.0/16, rev 1
        local binding:  label: 16
        remote binding: lsr: 2.2.2.2:0, label: 17

What does this output indicate?

Accepted Answer

The summary route 10.0.0.0/16 has both a local and remote label binding, indicating MPLS LDP is operational for this prefix.. This output shows MPLS LDP label bindings for the prefix 10.0.0.0/16. There is a local label (16) and a remote label (17) from LSR 2.2.2.2. This indicates that the summary route is label-switched, and LDP has successfully assigned labels for it.

Answer

The summary route is not label-switched because no local binding exists.

Answer

The remote binding indicates that the route is not being summarized.

Answer

The label bindings are for the more specific /24 routes, not the summary.

Question 4

A network engineer runs the following command to troubleshoot a Route Summarization issue:

R1# show ip nhrp detail
10.0.0.0/16 via 10.1.1.2, Tunnel0 created 00:01:00, expire 01:59:00
  Type: summary, Flags: used
  NBMA address: 192.168.1.2
  Registration: never

What does this output indicate?

Accepted Answer

The summary route 10.0.0.0/16 is learned via NHRP and is active, with the next hop being 192.168.1.2 over Tunnel0.. This output shows an NHRP cache entry for the summary route 10.0.0.0/16. The type is 'summary', indicating that this is a summary route learned via NHRP. The 'used' flag and NBMA address show that the route is active and pointing to a specific tunnel destination.

Answer

The summary route is not being used because the 'used' flag is not set.

Answer

The summary route is learned via EIGRP, not NHRP.

Answer

The summary route is a static route configured on the router.

Question 5

A network engineer runs the following command to troubleshoot a Route Summarization issue:

R1# show ip access-lists CoPP-ACL
extended IP access list CoPP-ACL
    10 permit eigrp any any (100 matches)
    20 permit ospf any any (50 matches)
    30 permit bgp any any (200 matches)
    40 deny ip any any (0 matches)

What does this output indicate?

Accepted Answer

CoPP is permitting routing protocol traffic, including EIGRP, OSPF, and BGP, which are used for route summarization. No drops indicate CoPP is not blocking summarization.. This output shows an access list used for Control Plane Policing (CoPP). The match counts indicate that EIGRP, OSPF, and BGP traffic are being permitted. The absence of matches on the deny statement suggests that no traffic is being dropped, which could indicate that CoPP is not affecting route summarization traffic.

Answer

CoPP is dropping all routing protocol traffic, preventing route summarization.

Answer

CoPP is only allowing BGP traffic, blocking EIGRP and OSPF summarization.

Answer

CoPP is not configured because the access list is empty.

Question 6

In EIGRP, what is the default behavior of auto-summary in IOS-XE versions 15.0 and later?

Accepted Answer

Auto-summary is disabled by default.. Cisco IOS-XE 15.0 and later have auto-summary disabled by default for EIGRP, unlike older IOS versions where it was enabled by default.

Answer

Auto-summary is enabled by default.

Answer

Auto-summary is enabled only for EIGRP named mode.

Answer

Auto-summary is disabled only for EIGRP classic mode.

Question 7

What is the default OSPF reference bandwidth used in the cost calculation formula on Cisco IOS?

Accepted Answer

100 Mbps. The default reference bandwidth is 100 Mbps, meaning the cost is calculated as 100,000,000 / interface bandwidth in bps.

Answer

10 Mbps

Answer

1000 Mbps

Answer

1 Gbps

Question 8

Which BGP attribute is used as the first tie-breaker when selecting the best path for route summarization?

Accepted Answer

Weight. The highest weight (locally configured) is the first tie-breaker in BGP path selection, before local preference.

Answer

Local preference

Answer

AS path length

Answer

MED

Question 9

In OSPF, what is the default hello interval on a point-to-point network type?

Accepted Answer

10 seconds. The default hello interval for OSPF on point-to-point networks is 10 seconds, as per RFC 2328.

Answer

30 seconds

Answer

40 seconds

Answer

20 seconds

Question 10

Which EIGRP packet type is used to confirm receipt of a route update during reliable transport?

Accepted Answer

ACK. EIGRP uses ACK packets (which are Hello packets with no data) to acknowledge reliable updates.

Answer

Hello

Answer

Update

Answer

Query

Question 11

What is the maximum hop count for a route in RIPv2 by default?

Accepted Answer

15. RIP uses a maximum hop count of 15, with 16 considered unreachable, to prevent routing loops.

Answer

16

Answer

255

Answer

32

Question 12

Which OSPF LSA type is used to advertise a summary route for a network outside the area but within the same OSPF domain?

Accepted Answer

Type 3. Type 3 LSAs (Summary LSAs) are generated by Area Border Routers (ABRs) to advertise inter-area routes.

Answer

Type 1

Answer

Type 2

Answer

Type 5

Question 13

In BGP, what is the default administrative distance for routes learned from an eBGP peer?

Accepted Answer

20. The default administrative distance for eBGP is 20, while iBGP has a default of 200.

Answer

200

Answer

120

Answer

110

Question 14

Which OSPF network type defaults to a 30-second hello interval and requires a DR/BDR election?

Accepted Answer

Non-broadcast (NBMA). Non-broadcast (NBMA) network type uses a 30-second hello interval and elects a DR/BDR, as per RFC 2328.

Answer

Broadcast

Answer

Point-to-point

Answer

Point-to-multipoint

Question 15

Drag and drop the steps to configure OSPF inter-area summarization on an ABR into the correct order, from first to last.

Accepted Answer

Enter OSPF router configuration mode. First, enter OSPF configuration mode for the process. Then, configure the area where the routes originate. Next, apply the range command to summarize prefixes into that area. After that, verify the summary route is present in the routing table. Finally, check that the summary is advertised to neighboring areas.