300-410 Practice Test 35 — 15 Questions

Question 1

A network engineer configured IP SLA 70 to monitor a remote site's LAN gateway (172.16.1.1) using ICMP echo. The IP SLA is linked to a track object that is used in a static route for a backup link. The engineer notices that the IP SLA state is 'Active', but the backup static route is installed in the routing table even when the primary route is available. What is the most likely cause?

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

Accepted Answer

The static route is configured without the 'track' keyword, so it is always installed regardless of the IP SLA state.. If the static route is configured without the 'track' keyword, the track object has no effect on that route — the route is installed unconditionally whenever its administrative distance is lower than competing routes. The IP SLA being 'Active' only confirms the probe is running, not that the route is bound to it. The most likely cause is that the track was never attached to the static route statement.

Answer

The IP SLA probe is failing intermittently, causing the track object to flap.

Answer

The primary route has a higher administrative distance than the static route.

Answer

The track object is configured with a delay that causes the static route to be installed prematurely.

Question 2

A network engineer runs the following command on Router R5:

R5# show logging | include %LINEPROTO-5-UPDOWN

*Mar  1 00:00:10.123: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up
*Mar  1 00:00:20.456: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down
*Mar  1 00:00:30.789: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up
*Mar  1 00:00:40.012: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down
*Mar  1 00:00:50.345: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up
*Mar  1 00:01:00.678: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down

Based on this output, what is the most likely problem?

Accepted Answer

There is a physical layer issue causing the interface to flap.. The output shows the line protocol on GigabitEthernet0/0 repeatedly changing between up and down, which indicates interface flapping. This is typically caused by a physical layer issue such as a faulty cable, bad port, or duplex mismatch. The other options are not supported by the output: administratively down would show a different message, high bandwidth delay product does not cause flapping, and high CPU load would not directly cause line protocol state changes.

Answer

The interface is administratively down.

Answer

The interface is configured with a high bandwidth delay product.

Answer

The router is experiencing a high CPU load due to routing updates.

Question 3

A network engineer configured the following:

monitor session 3 type erspan-source
 source interface GigabitEthernet0/0/2 rx
 destination
  erspan-id 2
  ip address 10.0.0.2
  origin ip address 10.0.0.1

What traffic will be mirrored?

Accepted Answer

Only traffic received on GigabitEthernet0/0/2.. The command 'source interface GigabitEthernet0/0/2 rx' specifies that only traffic received (rx) on GigabitEthernet0/0/2 will be mirrored. The 'rx' keyword indicates ingress traffic, so only incoming packets are copied to the ERSPAN destination.

Answer

Only traffic transmitted on GigabitEthernet0/0/2.

Answer

Both received and transmitted traffic on GigabitEthernet0/0/2.

Answer

All traffic on the router, regardless of interface.

Question 4

In BGP, what is the effect of using a route-map with a set community command but without the additive keyword?

Accepted Answer

The existing communities are overwritten by the specified community.. When set community is used without the additive keyword, it replaces any existing community attributes on the route with the specified community. With the additive keyword, the specified community is added to the existing communities.

Answer

The specified community is added to the existing communities.

Answer

The community attribute is not modified; the set command is ignored.

Answer

The route is denied if it already has communities.

Question 5

What is the default administrative distance for routes learned via OSPF in Cisco IOS?

Accepted Answer

110. OSPF has a default administrative distance of 110, as defined in Cisco IOS. This is used for route selection when multiple routing protocols provide the same prefix.

Answer

90

Answer

100

Answer

120

Question 6

In a VRF-Lite scenario with OSPF, what is the default network type on a physical Ethernet interface?

Accepted Answer

Broadcast. By default, OSPF sets the network type to broadcast on Ethernet interfaces, which enables DR/BDR election.

Answer

Point-to-point

Answer

Non-broadcast

Answer

Point-to-multipoint

Question 7

A network uses PBR to load-balance traffic from two subnets (10.1.1.0/24 and 10.2.2.0/24) across two ISPs (next-hops 100.64.1.1 and 100.64.2.2). After a routing change, traffic from 10.1.1.0/24 is being sent to both ISPs intermittently. Router R1 shows: 'show route-map' shows the route-map with two match clauses, 'debug ip policy' shows traffic from 10.1.1.0/24 being sent to both next-hops. What is the root cause?

Accepted Answer

The route-map has a match clause that matches both subnets, causing traffic to be load-balanced across both next-hops. Use specific ACLs or separate route-map entries.. PBR route-maps can have multiple match clauses, but if the route-map does not have a 'sequence' number or if the match clauses are not mutually exclusive, traffic can match multiple clauses. In this case, the route-map likely has a match clause that matches both subnets (e.g., using a less specific ACL), causing traffic from 10.1.1.0/24 to match both clauses and be load-balanced. The solution is to ensure the ACLs in the route-map are mutually exclusive or use separate route-map entries with sequence numbers.

Answer

The 'set ip next-hop' command is missing the 'load-balance' keyword, causing PBR to use both next-hops by default.

Answer

The routing table on R1 has equal-cost routes to both ISPs, causing PBR to be overridden by the routing table.

Answer

The interface where PBR is applied is in a VRF, causing the route-map to be applied incorrectly.

Question 8

Which of the following EEM event types can be used to trigger an applet based on a specific IOS command being entered?

Accepted Answer

event cli. The 'event cli' event type in EEM triggers an applet when a specific CLI command is entered. This allows automation based on command execution, such as running a script when a particular show command is issued. The other event types trigger on different conditions: syslog patterns, SNMP OIDs, or timers.

Answer

event syslog

Answer

event snmp

Answer

event timer

Question 9

Which THREE symptoms indicate that NAT is misconfigured or failing on a Cisco router? (Choose THREE.)

Accepted Answer

Inside hosts can ping the outside interface IP but cannot reach hosts beyond it.. Option A is correct because when inside hosts can ping the outside interface IP but cannot reach hosts beyond it, the router's interface is reachable but address translation is not occurring, so packets sourced from inside local addresses are not being translated to an inside global address and are dropped or unroutable on the outside. Option B is correct because NAT failures commonly produce asymmetric behavior: outbound packets may be translated and forwarded, but if the translation entry is missing, incorrect, or the return traffic cannot be mapped back to the inside local address, the reply is dropped, so only one direction of the flow succeeds. Option C is correct because seeing many translations sharing the same inside global address with different ports indicates PAT overload, and if new connections fail, the router has likely exhausted the available port range or the translation table, which is a classic NAT/PAT misconfiguration or capacity failure symptom. Option D is not correct because high CPU from the BGP process is a routing protocol issue, not a direct NAT misconfiguration or failure symptom. Option E is not correct because a default route pointing to the ISP next hop is a normal, expected routing configuration and does not by itself indicate NAT is misconfigured or failing.

Answer

The router's CPU utilization is high due to BGP process.

Answer

The show ip route command shows a default route pointing to the ISP next hop.

Question 10

Which THREE symptoms indicate that an administrative distance misconfiguration might be causing routing issues? (Choose THREE.)

Accepted Answer

The router prefers a route learned via a less reliable protocol over a more reliable one.. When AD is misconfigured, the router may prefer a less reliable route, causing suboptimal or intermittent connectivity. Common symptoms include incorrect route selection, flapping routes, and traffic taking unexpected paths. These are all signs that the AD values should be reviewed.

Answer

Routes are flapping in the routing table due to metric changes.

Answer

The routing table shows two routes to the same network with different AD values.

Question 11

A network engineer runs the following command on Router R9:

R9# show ip route 192.168.50.0
Routing entry for 192.168.50.0/24
  Known via "ospf 1", distance 110, metric 20
  Redistributing via ospf 1
  Last update from 10.0.0.1 on GigabitEthernet0/0, 00:00:10 ago
  Routing Descriptor Blocks:
  * 10.0.0.1, from 10.0.0.1, 00:00:10 ago, via GigabitEthernet0/0
      Route metric is 20, traffic share count is 1

R9 also has an EIGRP route for the same prefix with distance 90 and metric 28160. Which route will be installed?

Accepted Answer

The EIGRP route will be installed because it has a lower administrative distance.. EIGRP internal routes have a default administrative distance of 90, which is lower than OSPF's default distance of 110. Therefore, the EIGRP route will be preferred and installed in the routing table.

Answer

The OSPF route will be installed because it has a lower metric.

Answer

Both routes will be installed for load balancing.

Answer

Neither route will be installed due to a conflict.

Question 12

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 13

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 14

A network engineer runs the following command on Router R3:

R3# show logging | include %OSPF-5-ADJCHG

*Mar  1 00:05:10.123: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done
*Mar  1 00:06:20.456: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired
*Mar  1 00:07:30.789: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from DOWN to INIT, Received Hello
*Mar  1 00:08:40.012: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from INIT to EXSTART, Event: start
*Mar  1 00:09:50.345: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from EXSTART to EXCHANGE, Event: Negotiation Done
*Mar  1 00:10:00.678: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from EXCHANGE to LOADING, Event: Exchange Done
*Mar  1 00:11:10.901: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done
*Mar  1 00:12:20.234: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired

Based on this output, what is the most likely problem?

Accepted Answer

There is a Layer 1 or Layer 2 issue causing intermittent connectivity on GigabitEthernet0/0.. The log shows the OSPF neighbor repeatedly reaching FULL and then dropping with 'Dead timer expired,' which means the router stopped receiving Hello packets from the neighbor within the dead interval (default 40 seconds, 4× the 10-second Hello). This pattern — adjacency forms, then dies, then re-forms — is characteristic of intermittent Layer 1 or Layer 2 connectivity (flapping link, bad cable, duplex mismatch, or a flaky switch port) rather than a configuration mismatch. A config mismatch would prevent the adjacency from reaching FULL in the first place.

Answer

The OSPF process is misconfigured with mismatched area IDs.

Answer

The OSPF dead timer is set too high, causing slow convergence.

Answer

The router is running out of memory, causing OSPF process restarts.

Question 15

An engineer configures OSPF on two routers connected via a serial link. The MTU on one side is 1500 and on the other is 1400. The OSPF adjacency forms but stays stuck in EXSTART state. Which is the most likely explanation?

Accepted Answer

The router with the smaller MTU rejects DBD packets that exceed its MTU, preventing the exchange of LSAs.. OSPF uses the interface MTU to determine the maximum size of Database Description (DBD) packets. If the MTU mismatches, the router with the smaller MTU will reject DBD packets from the neighbor, causing the adjacency to remain in EXSTART state.

Answer

The router with the larger MTU cannot process OSPF hello packets from the neighbor.

Answer

The OSPF network type must be point-to-point for serial links; otherwise, the adjacency fails.

Answer

The OSPF process ID must match on both routers for adjacency to form.