300-410 Practice Test 35 — 15 Questions

Question 1

An engineer is troubleshooting an EIGRP convergence issue. After a link failure, the network takes an unusually long time to converge. The engineer notices that the EIGRP hello and hold timers are set to the default values. The network has many routers in a hub-and-spoke topology. What is the most likely cause of the slow convergence?

Accepted Answer

The hub router has too many EIGRP neighbors, causing CPU overload and dropped hello packets.. In a hub-and-spoke topology, if the hub router has a large number of neighbors, the default EIGRP timers may cause slow convergence because the hub must process many updates. Increasing the hello and hold timers on the hub can help reduce the load, but the issue here is that the timers are default, which can be too fast for a large number of neighbors, causing the hub to drop packets and reset adjacencies.

Answer

The EIGRP stub feature is not enabled on the spoke routers.

Answer

The EIGRP variance command is configured, causing unequal-cost load balancing.

Answer

The EIGRP router ID is not configured, so it defaults to the highest loopback IP.

Question 2

When an SNMP agent sends an InformRequest, what is the default behavior regarding acknowledgment?

Accepted Answer

The agent expects a Response PDU from the manager; if not received, it retransmits.. InformRequest requires the manager to send a Response; if no response is received, the agent retransmits.

Answer

The agent does not expect any acknowledgment; it is fire-and-forget.

Answer

The manager sends an acknowledgment at the transport layer only.

Answer

The agent sends the inform multiple times by default regardless of acknowledgment.

Question 3

A network engineer is troubleshooting an EIGRP issue where a route is flapping in and out of the routing table. The engineer checks the logs and sees messages indicating that the route is being learned from two different neighbors, but the metric keeps changing. The route is a summary route. What is the most likely cause of the flapping?

Accepted Answer

The summary route is being advertised by multiple routers with different metrics.. If a summary route is being learned from two different neighbors, and the metric changes, it could be because one of the neighbors is advertising the summary route with a different metric, causing the router to constantly switch between the two paths. However, the most common cause is that the summary route is being originated by multiple routers, and the metric is not consistent, leading to instability.

Answer

The EIGRP stub feature is configured on one of the neighbors.

Answer

The passive-interface command is applied to the interface receiving the summary route.

Answer

The EIGRP router ID is the same on both neighbors.

Question 4

What is the default retransmission timeout for SNMP informs on a Cisco IOS device?

Accepted Answer

30 seconds. The default timeout is 30 seconds; this is the time the agent waits for a Response before retransmitting.

Answer

5 seconds

Answer

60 seconds

Answer

10 seconds

Question 5

An engineer is troubleshooting an EIGRP issue where a router is not learning any routes from a neighbor, but the neighbor adjacency is up. The engineer checks the EIGRP topology table on the local router and sees that the neighbor is listed, but no routes from that neighbor are present. The engineer also verifies that the neighbor has routes to advertise. What is the most likely cause?

Accepted Answer

The neighbor is configured as an EIGRP stub router.. If the adjacency is up but no routes are received, the issue is likely that a distribute-list is filtering incoming routes, or the neighbor is configured as a stub router. In this case, the most common cause is that the neighbor is configured as a stub router, which restricts the routes it advertises.

Answer

The local router has a distribute-list out applied to the neighbor.

Answer

The EIGRP metric weights are different on the two routers.

Answer

The local router has a route-map applied to the EIGRP process that is filtering all routes.

Question 6

Which TWO statements correctly describe the behavior of SNMPv3 when using the 'noAuthNoPriv' security level? (Choose TWO.)

Accepted Answer

The SNMP engine ID is still used for message processing and identification.. SNMPv3 'noAuthNoPriv' provides no authentication and no encryption. The engine ID is still used for message processing, and the community string is replaced by the username. The security level is configured per user, not per group. The 'auth' and 'priv' keywords are omitted from the 'snmp-server user' command. The engine ID is automatically generated based on the router's MAC address or manually configured.

Answer

The username and password are sent in clear text.

Answer

The 'snmp-server user' command must include the 'auth' and 'priv' keywords set to 'md5' and 'des' respectively.

Answer

The security level is configured per user, not per group.

Question 7

A network engineer is troubleshooting an EIGRP issue where a router is not installing a route in the routing table, even though the route is present in the EIGRP topology table. The route is a feasible successor, but it is not being used. What is the most likely reason for this?

Accepted Answer

The feasible successor has a higher metric than the current successor.. EIGRP only installs the best route (successor) into the routing table. If a route is in the topology table as a feasible successor but not installed, it means that the feasible distance for that route is higher than the current successor's metric, so it is not the best path.

Answer

The route is a summary route that is being suppressed.

Answer

The route is being filtered by a distribute-list in.

Answer

The EIGRP variance command is set to 1, preventing unequal-cost load balancing.

Question 8

Which TWO actions will prevent an SNMPv2c NMS from receiving traps from a Cisco router? (Choose TWO.)

Accepted Answer

The NMS is configured with a community string that does not match the community string used in the 'snmp-server host' command on the router.. To receive traps, the NMS must be configured as a trap receiver with the correct community string, and the router must send traps to the correct IP and UDP port 162. If the community string on the NMS does not match the router's trap community, traps are discarded. If the router is configured to send traps to a different IP than the NMS, the NMS never receives them. The 'snmp-server enable traps' command enables trap generation; without it, no traps are sent. The 'snmp-server host' command specifies the destination; if omitted, traps are not sent. ACLs applied to the router's VTY lines do not affect SNMP trap traffic, which uses UDP port 162.

Answer

The router has an ACL applied to its VTY lines that denies UDP port 162.

Answer

The NMS is listening on UDP port 161 instead of UDP port 162.

Question 9

An engineer is troubleshooting an EIGRP issue where a router is not forming an adjacency with a neighbor over a Frame Relay point-to-point subinterface. The physical interface is up/up, and the subinterface is configured with an IP address. The engineer checks the EIGRP configuration and sees that the network statement includes the subnet of the subinterface. What is the most likely cause of the adjacency failure?

Accepted Answer

The subinterface is configured as multipoint instead of point-to-point.. On Frame Relay point-to-point subinterfaces, the default interface type is non-broadcast, and EIGRP by default uses multicast hellos. If the interface is not configured as a point-to-point type, or if the multicast capability is not enabled, EIGRP will not send hellos, and adjacency will not form.

Answer

The subinterface is not configured with the 'frame-relay interface-dlci' command.

Answer

The EIGRP hello timer is set to 0 on the subinterface.

Answer

The IP address on the subinterface is not in the same subnet as the neighbor.

Question 10

An engineer is troubleshooting an issue where an SNMPv2c NMS cannot poll interface counters on a Cisco router. Which THREE commands can be used to verify the SNMP configuration and connectivity? (Choose THREE.)

Accepted Answer

show snmp. To verify SNMP configuration, 'show snmp' displays community strings, trap receivers, and statistics. 'show snmp mib ifmib ifindex' shows interface indices used by SNMP. 'show snmp community' displays configured community strings and their access (RO/RW). 'show ip snmp' is not a valid command. 'debug snmp packet' shows SNMP packets in real time but is not a verification command; it is a troubleshooting tool that can impact performance.

Answer

show ip snmp

Answer

debug snmp packet

Question 11

A network engineer is troubleshooting an EIGRP issue where a router is not learning any routes from a neighbor, but the neighbor adjacency is up. The engineer checks the EIGRP topology table and sees that the neighbor is listed, but no routes are present. The engineer also checks the interface configuration and sees that the interface is configured as a passive interface under the EIGRP process. What is the most likely cause of the issue?

Accepted Answer

The neighbor is configured with a distribute-list that filters all routes.. If an interface is configured as passive under EIGRP, the router will not send or receive hello packets on that interface, which prevents adjacency formation. However, if the adjacency is up, the passive-interface command is not the issue. In this case, the adjacency is up, so passive-interface is not the cause.

Answer

The passive-interface command is preventing the router from sending updates, but not receiving them.

Answer

The EIGRP process is configured with the 'no auto-summary' command.

Answer

The router ID is not configured, so EIGRP is using the highest loopback IP.

Question 12

An engineer is troubleshooting an EIGRP issue where a router is not learning a specific route from a neighbor, but other routes from the same neighbor are being learned. The engineer checks the EIGRP topology table and sees that the route is not present. The engineer also checks the neighbor's routing table and confirms that the route exists. What is the most likely cause?

Accepted Answer

A distribute-list in is applied on the local router that filters the specific route.. If only one route is missing from a neighbor, the issue is likely that the route is being filtered by a distribute-list or route-map on the receiving router. Since other routes are received, the filter is specific to that route.

Answer

The neighbor is configured as a stub router.

Answer

The route is a summary route that is being suppressed by the 'summary-address' command.

Answer

The EIGRP metric for the route is too high, so it is not considered feasible.

Question 13

Which TWO statements about SNMPv3 engine ID configuration are true? (Choose TWO.)

Accepted Answer

If the engine ID is changed, all existing SNMPv3 users must be reconfigured.. The SNMP engine ID uniquely identifies an SNMPv3 entity. It can be manually configured with the 'snmp-server engine-id' command. If not configured, it is automatically generated based on the router's MAC address. The engine ID must be unique within a management domain. Changing the engine ID invalidates existing SNMPv3 users (keys are re-derived). The engine ID is used for message processing and key generation.

Answer

The engine ID must be manually configured for SNMPv3 to function.

Answer

The engine ID can be up to 64 octets in length.

Answer

The engine ID is automatically generated based on the router's serial number.

Question 14

A network engineer runs the following command on Router R1:

R1# show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(100)
H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq
                                           (sec)         (ms)       Cnt Num
0   10.1.1.2                Gi0/0            13 00:12:34   12   200  0  45
1   10.2.2.2                Gi0/1            12 00:10:20   15   200  0  32
2   10.3.3.2                Gi0/2            14 00:08:15   18   200  0  28
3   10.4.4.2                Gi0/3            13 00:06:10   20   200  0  22

Based on this output, which statement is correct?

Accepted Answer

All four EIGRP neighbors are in the established state and exchanging routes.. The show ip eigrp neighbors command displays all EIGRP neighbors. The 'H' column shows the order in which neighbors were learned. The 'Hold' column shows the remaining hold time in seconds. All neighbors are in a stable state with low SRTT and RTO values, and no outstanding packets (Q Cnt = 0). The output indicates that all four neighbors are fully operational.

Answer

Neighbor 10.4.4.2 has a high SRTT of 20 ms, indicating a slow link.

Answer

The Q Cnt of 0 means that there are 0 packets queued for retransmission, but this could indicate a problem.

Answer

The neighbor on Gi0/3 has the lowest uptime, so it may be flapping.

Question 15

A network engineer runs the following command on Router R1:

R1# show ip eigrp topology all-links
EIGRP-IPv4 Topology Table for AS(100)/ID(192.168.1.1)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status

P 10.10.10.0/24, 1 successors, FD is 28160, Qos: 0
     via 10.1.1.2 (28160/28160), GigabitEthernet0/0
     via 10.2.2.2 (28672/28160), GigabitEthernet0/1
P 10.20.20.0/24, 1 successors, FD is 28160, Qos: 0
     via 10.2.2.2 (28160/28160), GigabitEthernet0/1
     via 10.3.3.2 (28672/28160), GigabitEthernet0/2

Based on this output, which statement is correct?

Accepted Answer

The network has redundant paths with feasible successors for both routes.. The all-links output shows all known routes, including feasible successors. For 10.10.10.0/24, there is a successor via 10.1.1.2 and a feasible successor via 10.2.2.2 (since its reported distance of 28160 is less than the FD of 28160). For 10.20.20.0/24, there is a successor via 10.2.2.2 and a feasible successor via 10.3.3.2. This indicates good redundancy.

Answer

The route to 10.20.20.0/24 has no feasible successor.

Answer

The FD for 10.10.10.0/24 is 28672.

Answer

The route to 10.10.10.0/24 is in Active state.