300-410 Mock Exam 74 — 25 Questions

Question 1

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 2

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

R1# show ip route 172.16.0.0 255.255.0.0
Routing entry for 172.16.0.0/16
  Known via "ospf 1", distance 110, metric 20, type intra area
  Last update from 10.1.1.2 on GigabitEthernet0/0, 00:00:05 ago
  Routing Descriptor Blocks:
  * 10.1.1.2, from 2.2.2.2, 00:00:05 ago, via GigabitEthernet0/0
      Route metric is 20, traffic share count is 1

What does this output indicate?

Accepted Answer

The route is an OSPF intra-area route with administrative distance 110, which is the default for OSPF.. The output shows an OSPF intra-area route with administrative distance 110, which is the default for OSPF. The metric is 20, and the route is learned from neighbor 2.2.2.2.

Answer

The route is an OSPF external route with administrative distance 110.

Answer

The route has an administrative distance of 20 because it is an OSPF route.

Answer

The route is preferred over an EIGRP route with AD 90.

Question 3

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 4

Which default administrative distance is assigned to a directly connected interface route?

Accepted Answer

0. Directly connected routes have a default administrative distance of 0, indicating the highest preference.

Answer

1

Answer

5

Answer

110

Question 5

An engineer configures IP SLA with an ICMP echo operation and tracks it with a static route. The IP SLA operation is configured with a source interface of Loopback0. The engineer notices that when the remote host becomes unreachable, the static route is removed, but when the remote host becomes reachable again, the static route is not reinstalled immediately. The show ip sla statistics shows the operation is 'Active' and 'Success'. Which is the most likely explanation?

Accepted Answer

The track object has a 'delay up' configured, causing a delay before the route is reinstalled.. When an IP SLA operation uses a source interface, the operation may fail if that interface is down, but more importantly, the track object may have a delay configured for up transitions. Additionally, the static route may have a higher administrative distance that prevents it from being reinstalled if another route to the same prefix exists. However, the most common edge case is that the track object has a 'delay up' configured, which delays the route installation after the operation recovers.

Answer

The static route has a higher administrative distance than the default route, so it is not installed.

Answer

The IP SLA operation uses a source interface that is not reachable from the remote host, causing asymmetric routing.

Answer

The IP SLA operation has a frequency that is too high, causing the router to ignore the results.

Question 6

A network engineer configures Flexible NetFlow to export traffic statistics for a VRF named CUSTOMER_A. The configuration includes 'flow exporter EXPORTER' with destination 10.10.10.10:2055 and 'vrf CUSTOMER_A' under the exporter. The flow monitor is applied to the VRF interface. However, 'show flow monitor name MONITOR cache' shows no entries for VRF traffic. What is the most likely cause?

Accepted Answer

The flow monitor is applied to the global routing table interface instead of the VRF interface.. For VRF-aware NetFlow, the flow monitor must be applied using the 'ip flow monitor MONITOR input' command under the VRF interface, and the exporter must reference the VRF. A common mistake is forgetting to apply the monitor to the interface in the VRF context.

Answer

The exporter is missing the 'source' interface command.

Answer

The VRF is not configured with 'ip flow-export' commands.

Answer

The flow record does not match any VRF-specific fields.

Question 7

Which TWO statements about route summarization in EIGRP are true? (Choose TWO.)

Accepted Answer

EIGRP automatic summarization is enabled by default for classful networks.. EIGRP supports manual summarization on any interface using the 'ip summary-address eigrp' command, and automatic summarization is enabled by default for classful networks. EIGRP does not support automatic summarization at the classful boundary for all networks; it is only for major network boundaries. Summarization in EIGRP does not require a route-map, and it can be configured on any interface, not just serial interfaces.

Answer

EIGRP supports automatic summarization for all types of networks, including discontiguous subnets.

Answer

Route summarization in EIGRP requires the use of a route-map to define the summary prefix.

Answer

Manual summarization can only be applied to serial interfaces.

Question 8

Which IP SLA operation type uses ICMP Echo Request/Reply packets to measure round-trip time?

Accepted Answer

ICMP Echo. The IP SLA ICMP Echo operation (type 1) uses ICMP Echo Request and Echo Reply messages to measure network latency and availability.

Answer

UDP Jitter

Answer

TCP Connect

Answer

HTTP

Question 9

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

R1# show ip bgp 10.0.0.0/16
BGP routing table entry for 10.0.0.0/16, version 2
Paths: (1 available, best #1, table default)
  Advertised to update-groups:
     1
  Refresh Epoch 1
  Local, (aggregated by 65000 1.1.1.1)
    10.1.1.2 from 10.1.1.2 (2.2.2.2)
      Origin IGP, metric 0, localpref 100, valid, external, best
      Atomic-aggregate

What does this output indicate?

Accepted Answer

The route 10.0.0.0/16 is an aggregate route, and the atomic-aggregate attribute indicates that the AS path may be incomplete.. This output shows the BGP table entry for prefix 10.0.0.0/16. The path is marked as 'aggregated', indicating it is a summary route. The 'Atomic-aggregate' attribute suggests that the route is an aggregate and may have lost some AS path information.

Answer

The route is a normal BGP learned route without summarization.

Answer

The route is suppressed and not advertised to neighbors.

Answer

The route is learned via redistribution from OSPF.

Question 10

Which default administrative distance is assigned to routes learned via the Open Shortest Path First (OSPF) protocol?

Accepted Answer

110. OSPF routes have a default administrative distance of 110, as defined by Cisco IOS.

Answer

90

Answer

115

Answer

120

Question 11

Drag and drop the steps to troubleshoot IP SLA adjacency or connectivity failures into the correct order, from first to last.

Accepted Answer

Verify IP SLA operation state with 'show ip sla statistics'. Start by verifying the IP SLA operation state to see if it is active or failed, then check reachability to the target using extended ping with the same source, inspect the IP SLA configuration for errors, review access lists or routing that may block probes, and finally adjust parameters like threshold or timeout as needed.

Question 12

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 13

Which IP SLA operation type uses ICMP to discover the path (hops) between source and destination?

Accepted Answer

ICMP Path Echo. The ICMP Path Echo operation (type 10) uses ICMP Echo requests with increasing TTL values to trace the path from source to destination, similar to traceroute.

Answer

ICMP Echo

Answer

UDP Jitter

Answer

TCP Connect

Question 14

A network engineer is troubleshooting BGP route summarization on a border router that advertises a summary route 172.16.0.0/16 to an ISP neighbor. The engineer notices that the ISP is receiving the summary route but also receiving the more specific routes (172.16.1.0/24, 172.16.2.0/24), causing suboptimal routing. What should the engineer do to ensure only the summary route is advertised?

Accepted Answer

Use the 'aggregate-address 172.16.0.0 255.255.0.0 summary-only' command under the BGP process.. In BGP, to suppress more specific routes when advertising a summary, the engineer must use the 'aggregate-address' command with the 'summary-only' keyword.

Answer

Configure the 'network' command for the summary route and remove the network statements for the specific subnets.

Answer

Apply a route-map to the neighbor to filter out the specific routes using an ACL.

Answer

Configure the 'summary-address' command under the BGP process.

Question 15

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

R1# show ip ospf database summary 10.0.0.0

OSPF Router with ID (1.1.1.1) (Process ID 1)

Summary Net Link States (Area 0)

LS age: 100
  Options: (No TOS-capability, DC)
  LS Type: Summary Links(Network)
  Link State ID: 10.0.0.0 (summary Network Number)
  Advertising Router: 2.2.2.2
  LS Seq Number: 80000001
  Checksum: 0x1234
  Length: 28
  Network Mask: /16
        TOS: 0  Metric: 20

What does this output indicate?

Accepted Answer

The summary route 10.0.0.0/16 is being advertised by router 2.2.2.2 as a Type 3 LSA into Area 0.. This output shows the OSPF database entry for a summary route 10.0.0.0/16. The LS Type is Summary Links, indicating it is a Type 3 LSA generated by an ABR (advertising router 2.2.2.2). The metric of 20 suggests it is a summary route injected into Area 0.

Answer

The summary route is a Type 5 external LSA from an ASBR.

Answer

The summary route is a Type 1 router LSA from router 2.2.2.2.

Answer

The summary route is not installed because the metric is too high.

Question 16

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 17

What is the default frequency (in seconds) for an IP SLA operation when no frequency is explicitly configured?

Accepted Answer

60 seconds. The default frequency for an IP SLA operation is 60 seconds. This means the probe is sent every 60 seconds unless a different frequency is configured under the IP SLA configuration.

Answer

10 seconds

Answer

30 seconds

Answer

120 seconds

Question 18

Examine this partial configuration on router R3:

flow record RECORD-2
 match ipv4 source address
 match ipv4 destination address
 match ipv4 protocol
 match transport source-port
 match transport destination-port
 collect counter bytes
 collect counter packets
!
flow monitor MONITOR-3
 record RECORD-2
 cache timeout active 60
 cache timeout inactive 15
!
interface GigabitEthernet0/3
 ip flow monitor MONITOR-3 input
 ip flow monitor MONITOR-3 output
!

Which statement is true about this configuration?

Accepted Answer

The router will create separate flow records for traffic entering and leaving GigabitEthernet0/3, doubling the cache entries.. This question tests understanding of bidirectional flow monitoring and cache timeout interaction.

Answer

The router will aggregate input and output flows into a single cache entry for each unique flow.

Answer

The inactive timeout of 15 seconds will cause flows to be exported only after 15 seconds of inactivity, overriding the active timeout.

Answer

The configuration is invalid because a flow monitor cannot be applied to both input and output on the same interface.

Question 19

Which TWO configuration steps are required to implement manual route summarization in OSPF on an ABR? (Choose TWO.)

Accepted Answer

Configure the 'area area-id range network mask' command under router OSPF configuration.. In OSPF, manual summarization on an ABR is done using the 'area range' command under router configuration mode, which summarizes routes from one area into another. The summary address must be within the range of networks in the area. The 'summary-address' command is used for external routes on ASBRs, not for inter-area summarization. 'network' commands define interfaces, not summarization. 'default-information originate' is for default routes.

Answer

Use the 'summary-address network mask' command under router OSPF configuration.

Answer

Apply the 'ip summary-address ospf' command under the interface connecting to the backbone.

Answer

Configure a 'network' statement that matches the summary address.

Question 20

An engineer configures Flexible NetFlow with a flow record that includes 'match ipv4 protocol' and 'collect counter packets'. The flow monitor is applied to an interface. 'show flow monitor name MONITOR cache' shows flows, but the packet counts are much lower than expected based on interface counters. What is the most likely cause?

Accepted Answer

The flow monitor is applied only in the ingress direction, missing egress traffic.. Flexible NetFlow uses sampled NetFlow by default unless 'sampler' is explicitly configured. However, the default sampling rate is 1 (no sampling). The issue might be that the monitor is applied only in one direction (ingress or egress) while traffic is bidirectional, so only half the traffic is captured.

Answer

The flow record does not include 'match ipv4 source address', causing flows to be aggregated incorrectly.

Answer

The router is using sampled NetFlow with a default sampling rate of 1:1000.

Answer

The flow exporter is rate-limiting the export, causing cache entries to be dropped before counting.