300-410 Mock Exam 73 — 25 Questions

Question 1

A large enterprise network is experiencing intermittent connectivity between Site A (R1) and Site B (R2) over an MPLS L3VPN. R1 has the following relevant configuration: route-map RMAP-IN permit 10 match ip address prefix-list PL-ALLOW set extcommunity rt 100:1. Router R2 shows: 'show bgp vpnv4 unicast all neighbors 10.1.1.1 received-routes' lists only the default route, but 'show ip route vrf CUSTOMER' shows no default route. What is the root cause?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The route-map RMAP-IN is missing a permit statement for other prefixes, causing implicit deny of all routes except the default.. The route-map RMAP-IN on R1 is configured to set the route-target extended community (RT) on incoming BGP VPNv4 routes. However, the route-map is applied inbound on the BGP session, which means it modifies routes received from R2. The match condition uses prefix-list PL-ALLOW, which likely permits only the default route. The set extcommunity rt 100:1 command overwrites or adds the RT, but if the route-map does not explicitly permit other routes (e.g., via a subsequent permit statement), those routes are denied by the implicit deny at the end of the route-map. This causes R1 to reject all routes except the default, but the default route may not be installed in the VRF due to missing RT matching or other VRF configuration issues. The correct fix is to add a permit statement for all necessary prefixes or remove the route-map from the neighbor statement.

Answer

The prefix-list PL-ALLOW is misconfigured and does not match the default route correctly.

Answer

The VRF CUSTOMER on R1 is missing the route-target import 100:1 command.

Answer

The BGP session between R1 and R2 is flapping due to a mismatch in the BGP update-source.

Question 2

In Cisco IOS-XE, what is the default behavior of the 'route-map' command when no 'match' or 'set' clauses are configured?

Accepted Answer

It permits all routes and applies no changes.. A route-map without any match or set clauses is a permit statement that matches all routes and performs no modifications. This is a common source of unintended route filtering.

Answer

It denies all routes by default.

Answer

It permits all routes and sets the metric to 0.

Answer

It denies all routes and logs the action.

Question 3

A network engineer is troubleshooting NAT for a VoIP phone that uses SIP. The phone is at 192.168.2.10, and the router performs PAT to the outside interface 198.51.100.1. The phone can register with the SIP server, but calls fail after 30 seconds. The engineer notices that the SIP signaling includes the phone's private IP in the SDP body. What is the most likely cause?

Accepted Answer

The router's SIP ALG is disabled, so the private IP in the SDP is not translated.. The SIP signaling includes the phone's private IP in the SDP body, which is used for media negotiation. When the router's SIP Application Layer Gateway (ALG) is disabled, it does not inspect and translate the private IP addresses embedded in the SDP payload. As a result, the SIP server sends media (RTP) to the private IP 192.168.2.10, which is unreachable from outside, causing the call to fail after the initial registration and signaling succeed.

Answer

The PAT port range is exhausted.

Answer

The phone's default gateway is misconfigured.

Answer

The outside interface has a firewall blocking UDP ports.

Question 4

What is the default frequency (in seconds) for an IP SLA operation if not explicitly configured?

Accepted Answer

60 seconds. The default frequency for IP SLA operations is 60 seconds. This means probes are sent every 60 seconds unless overridden with the frequency command.

Answer

10 seconds

Answer

30 seconds

Answer

120 seconds

Question 5

Drag and drop the steps to apply a route-map to filter BGP prefix advertisements into the correct order, from first to last.

Accepted Answer

Define route-map with permit/deny and match conditions. First, define the route-map with a permit or deny clause and match criteria. Second, configure the set actions to modify attributes. Third, apply the route-map to the BGP neighbor using the neighbor route-map command. Fourth, clear the BGP session to activate the filter. Finally, verify the filtered prefixes using show ip bgp.

Question 6

Which TWO commands are used to configure an IP SLA ICMP echo operation on a Cisco IOS device? (Choose TWO.)

Accepted Answer

ip sla 1. To configure an IP SLA ICMP echo operation, you start with 'ip sla ' to enter IP SLA configuration mode, then use 'icmp-echo [source-ip ]' to define the probe. The 'frequency' command sets how often the probe is sent. The 'ip sla schedule' is used to start the operation, not to configure it. The 'track' command is used separately to monitor the operation. The 'ip sla monitor' is legacy.

Answer

ip sla schedule 1 life forever start-time now

Answer

track 1 ip sla 1 reachability

Answer

ip sla monitor 1

Question 7

Consider this IP SLA configuration on router R6:

ip sla 60
 udp-echo 203.0.113.1 2000 source-ip 198.51.100.1
 frequency 20
ip sla schedule 60 life forever start-time now

What is the purpose of this configuration?

Accepted Answer

It tests UDP connectivity by sending a UDP packet and expecting a response.. The configuration sends UDP packets to destination 203.0.113.1 on port 2000, sourced from 198.51.100.1, every 20 seconds. It tests UDP connectivity and response time.

Answer

It tests ICMP echo instead of UDP.

Answer

It measures jitter and packet loss.

Answer

It will only work if the destination is a Cisco router.

Question 8

Which TWO commands can be used to verify the administrative distance of a route in a Cisco IOS router? (Choose TWO.)

Accepted Answer

show ip route. The show ip route command displays the routing table including the administrative distance for each route. The show ip protocols command displays routing protocol parameters including the default and any configured administrative distances. The other options either do not show administrative distance or are incorrect commands.

Answer

show ip interface brief

Answer

show running-config | include distance

Answer

show ip ospf interface

Question 9

Examine this configuration snippet:
```
router rip
 distance 120
```
Which statement is true about the effect of this command?

Accepted Answer

It changes the administrative distance for RIP routes to 120, which is the same as the default, so no change occurs.. The `distance` command under RIP sets the administrative distance for all RIP routes to 120, overriding the default of 120? Actually default is 120, so this command would have no effect if set to the same value.

Answer

It changes the administrative distance for RIP routes to 120, which is lower than the default of 130.

Answer

It changes the administrative distance for RIP routes to 120, but only for routes learned from RIP neighbors.

Answer

It changes the administrative distance for RIP routes to 120, but only for routes with a hop count greater than 1.

Question 10

Which TWO commands can be used to verify the effect of a route-map applied to a BGP neighbor? (Choose TWO.)

Accepted Answer

show ip bgp neighbors x.x.x.x advertised-routes. The commands 'show ip bgp neighbors x.x.x.x advertised-routes' and 'show ip bgp neighbors x.x.x.x routes' directly show the routes being sent or received after route-map filtering. 'show route-map' only displays the route-map definition, not its effect on a specific neighbor. 'show ip bgp' displays the BGP table without neighbor-specific filtering context. 'show ip bgp neighbors' alone does not show the filtered routes.

Answer

show route-map

Answer

show ip bgp

Answer

show ip bgp neighbors x.x.x.x

Question 11

Consider the following configuration on a router running BGP and OSPF:
```
router bgp 65000
 distance bgp 20 200 200
```
What is the effect of this command?

Accepted Answer

It sets the administrative distance for eBGP routes to 20, iBGP routes to 200, and local BGP routes to 200.. The `distance bgp` command sets AD for BGP routes: external (eBGP) to 20, internal (iBGP) to 200, and local to 200.

Answer

It sets the administrative distance for all BGP routes to 20.

Answer

It sets the administrative distance for eBGP routes to 200 and iBGP routes to 20.

Answer

It sets the administrative distance for BGP routes to 20 for routes learned from AS 65000.

Question 12

A network engineer runs the following command to troubleshoot an IP SLA issue:

R1# show ip sla history 10

Point by Point History
Entry = 10
   Life = 1
   Time of Event = 12:34:56.789 UTC Mon Mar 1 2021
   Start Time = 12:34:56.789 UTC Mon Mar 1 2021
   Completion Time = 12:34:57.001 UTC Mon Mar 1 2021
   Return Code = OK
   RTT = 12 ms

Life = 2
   Time of Event = 12:35:56.789 UTC Mon Mar 1 2021
   Start Time = 12:35:56.789 UTC Mon Mar 1 2021
   Completion Time = 12:35:57.001 UTC Mon Mar 1 2021
   Return Code = OK
   RTT = 14 ms

Life = 3
   Time of Event = 12:36:56.789 UTC Mon Mar 1 2021
   Start Time = 12:36:56.789 UTC Mon Mar 1 2021
   Completion Time = 12:36:57.001 UTC Mon Mar 1 2021
   Return Code = OK
   RTT = 11 ms

What does this output indicate?

Accepted Answer

The IP SLA operation shows a history of successful probes with low RTT values.. This output shows historical data for IP SLA operation 10. Each entry shows a successful probe with RTT around 11-14 ms, indicating consistent performance over time.

Answer

The IP SLA operation has experienced multiple timeouts.

Answer

The IP SLA operation has failed because the RTT values are inconsistent.

Answer

The IP SLA operation is not configured because no history is shown.

Question 13

In EIGRP, what is the default administrative distance of a summary route created with the 'ip summary-address eigrp' command?

Accepted Answer

5. By default, EIGRP summary routes have an administrative distance of 5, which is lower than the default distance of 90 for internal EIGRP routes.

Answer

90

Answer

170

Answer

1

Question 14

A network engineer configured IP SLA to track a BGP next-hop for a backup path. Router R1 has:

ip sla 2
 icmp-echo 192.168.2.2 source-ip 192.168.1.1
 frequency 5
ip sla schedule 2 life forever start-time now

track 2 ip sla 2 reachability

router bgp 65001
 bgp log-neighbor-changes
 neighbor 192.168.2.2 remote-as 65002
 neighbor 192.168.2.2 fall-over bfd
 neighbor 192.168.2.2 track 2

However, when the link to 192.168.2.2 goes down, the BGP session does not reset immediately. What is the root cause?

Accepted Answer

The BGP fall-over bfd command takes precedence over the track, and since BFD is not fully operational, the session does not reset.. The BGP fall-over bfd command overrides the track 2 behavior. BFD provides faster detection, but if BFD is not configured on the neighbor or if the BFD session is not established, the track might not take effect. The correct answer is that the track 2 is ignored because BGP fall-over bfd takes precedence, and BFD is not actually operational.

Answer

The IP SLA frequency is too low, so the track does not detect the failure quickly enough.

Answer

The source IP in the IP SLA must match the BGP update-source; otherwise, the track is ignored.

Answer

The track 2 is not applied to the BGP neighbor correctly; it should be under the address-family.

Question 15

Which TWO statements about the behavior of route-map sequence numbers and the "continue" clause in Cisco IOS are true? (Choose TWO.)

Accepted Answer

A route-map sequence with no match command matches all routes and applies any set commands.. The continue clause allows a route-map to jump to a later sequence after a match, but not to an earlier one. If a sequence does not have a match statement, it matches all routes by default. The default action for an unmatched route is to deny (implicit deny). The continue clause is processed only if the current sequence matches and the set actions are applied; it does not skip the current sequence's processing. Sequence numbers are evaluated in ascending order, and the first match wins.

Answer

The continue clause can cause evaluation to jump to a lower sequence number.

Answer

If a route does not match any sequence, it is permitted by default.

Answer

When a route matches a sequence with a continue clause, the continue is processed before any set commands in that sequence.

Question 16

Consider this IP SLA configuration on router R3:

ip sla 30
 icmp-echo 192.168.2.1
 frequency 5
ip sla schedule 30 life forever start-time now

What is missing from this configuration?

Accepted Answer

A source IP address is missing; the router will use the outgoing interface IP.. The configuration lacks a source IP address. While optional, without a source-ip, the router uses the outgoing interface IP, which may not be desired for tracking specific paths.

Answer

The frequency is too low; it should be at least 60 seconds.

Answer

The destination IP is invalid; it must be a multicast address.

Answer

The operation type is wrong; it should be udp-echo.

Question 17

Which TWO commands would a network engineer use to verify the status of local authentication and authorization for device access control on a Cisco IOS router? (Choose TWO.)

Accepted Answer

show aaa local user lockout. 'show aaa local user lockout' displays whether local users have been locked out due to failed authentication attempts, which is directly relevant to verifying local authentication and authorization status. Option B is correct because 'show running-config | include aaa authentication login' shows the configured AAA authentication method lists for login, allowing verification of local authentication policies.

Answer

show aaa servers

Answer

debug aaa authentication

Answer

show ip local policy

Question 18

An engineer configures IP SLA to track a route to a server that is reachable via a GRE tunnel. Router R1 has:

ip sla 9
 icmp-echo 172.16.0.1 source-ip 10.0.0.1
 frequency 10
ip sla schedule 9 life forever start-time now

track 9 ip sla 9 reachability

ip route 192.168.2.0 255.255.255.0 Tunnel0 track 9

The GRE tunnel is up, but the route is flapping. Show output on R1:

show interface Tunnel0
Tunnel0 is up, line protocol is up

show track 9
Track 9
  IP SLA 9 reachability
  Reachability is Up
  10 changes, last change 00:00:05

What is the root cause?

Accepted Answer

The GRE tunnel has a path MTU issue that causes ICMP packets to be fragmented or dropped, leading to intermittent probe failures.. The IP SLA probe is successful, but the track is flapping. This could be due to the IP SLA probe itself being intermittent, perhaps because the GRE tunnel is using a path that has high latency or packet loss. The correct answer is that the IP SLA probe is being affected by the GRE tunnel's path MTU or fragmentation issues, causing some probes to be dropped.

Answer

The IP SLA frequency is too high, causing the router to overload.

Answer

The source IP 10.0.0.1 is not reachable from the tunnel destination.

Answer

The track 9 is not correctly associated with the route.

Question 19

Which TWO statements about administrative distance are true? (Choose TWO.)

Accepted Answer

A lower administrative distance is preferred over a higher one.. Administrative distance is used to select the best route when multiple routing protocols provide routes to the same destination. A lower administrative distance is preferred. The default administrative distance for OSPF is 110, and for EIGRP it is 90 (internal) or 170 (external).

Answer

The default administrative distance for OSPF is 90.

Answer

Administrative distance is used to compare routes within the same routing protocol.

Answer

The default administrative distance for EIGRP internal routes is 170.

Question 20

Examine this configuration:
```
router ospf 1
 distance ospf intra-area 150 inter-area 160 external 170
```
What is the effect of this command?

Accepted Answer

It sets the administrative distance for intra-area OSPF routes to 150, inter-area to 160, and external to 170.. This command sets different administrative distances for different OSPF route types: intra-area to 150, inter-area to 160, external to 170.

Answer

It sets the administrative distance for all OSPF routes to 150.

Answer

It sets the administrative distance for OSPF routes to 150, but only for routes learned from area 1.

Answer

It sets the administrative distance for OSPF external routes to 170 and leaves intra-area and inter-area at default.