300-410 Practice Test 37 — 15 Questions

Question 1

An engineer configures SNMPv2c with a read-only community string 'public' on a router. The NMS can poll interface statistics, but when trying to poll OSPF neighbor states, the NMS receives no response. Which is the most likely explanation?

Accepted Answer

The OSPF MIB is not supported or not loaded on the router.. SNMP view-based access control (VACM) can restrict which MIB objects are accessible. The default view for SNMPv2c includes many objects, but OSPF MIB objects may be excluded if the view is customized or if the OSPF MIB is not loaded.

Answer

The community string 'public' is not allowed to access the OSPF MIB due to a missing 'snmp-server view' command.

Answer

OSPF neighbor states are only available via SNMPv3 due to security restrictions.

Answer

The NMS must use the OSPF process ID in the OID to poll neighbor states.

Question 2

Given the following EIGRP configuration on Router R2:

router eigrp 200
 network 192.168.1.0
 network 10.0.0.0
 no auto-summary

Which statement is true about the operation of EIGRP?

Accepted Answer

EIGRP will advertise 192.168.1.0/24 and 10.0.0.0/8 as exact prefixes.. The no auto-summary command disables automatic summarization at classful boundaries, so EIGRP will advertise subnets exactly as configured under the network statements.

Answer

EIGRP will automatically summarize 192.168.1.0 to 192.168.0.0/16.

Answer

EIGRP will only advertise the classful networks 192.168.0.0/16 and 10.0.0.0/8.

Answer

EIGRP will not form neighbor adjacencies due to missing network mask.

Question 3

Which TWO commands would a network engineer use to verify that EIGRP is correctly forming neighbor adjacencies and exchanging routes on an interface? (Choose TWO.)

Accepted Answer

show ip eigrp neighbors. The 'show ip eigrp neighbors' command lists all established neighbors and their interface details, confirming adjacency. The 'show ip eigrp interfaces' command displays interfaces on which EIGRP is active and includes neighbor count, verifying that the interface is participating in EIGRP. The other commands either show routes (not neighbor state) or are not EIGRP-specific.

Answer

show ip route eigrp

Answer

show ip protocols

Answer

show ip ospf neighbor

Question 4

Examine the following EIGRP configuration on Router R3:

interface GigabitEthernet0/1
 ip bandwidth-percent eigrp 100 50

What is the effect of this command?

Accepted Answer

EIGRP will limit its control traffic to 50% of the interface bandwidth.. This command limits the EIGRP bandwidth usage on the interface to 50% of the configured interface bandwidth. It affects how much bandwidth EIGRP can use for control traffic.

Answer

EIGRP will use only 50% of the interface bandwidth for data traffic.

Answer

EIGRP will adjust the metric calculation to use 50% of the bandwidth.

Answer

EIGRP will form neighbor adjacencies only when bandwidth usage is below 50%.

Question 5

Which TWO statements about EIGRP stub routing are true when troubleshooting a hub-and-spoke topology? (Choose TWO.)

Accepted Answer

A stub router advertises only connected and summary routes to its neighbors.. EIGRP stub routers advertise only connected and summary routes to their neighbors, preventing them from being used as transit. The stub feature must be configured on the spoke router; the hub router does not need stub configuration. Options C and D are false because stub routers do not query for lost routes (they reply with 'Stub'), and they still advertise connected routes by default.

Answer

The stub feature is configured on the hub router to limit queries from spokes.

Answer

A stub router will send a query to its neighbors if it loses a route.

Answer

Stub routers do not advertise any connected routes unless specifically configured.

Answer

The hub router must have the stub command configured to accept stub advertisements.

Question 6

Examine the following EIGRP configuration on Router R6:

interface GigabitEthernet0/2
 ip hello-interval eigrp 100 15
 ip hold-time eigrp 100 45

What is the effect of these commands?

Accepted Answer

EIGRP will send hello packets every 15 seconds and wait 45 seconds before declaring a neighbor down.. These commands change the EIGRP hello interval to 15 seconds and hold time to 45 seconds on the interface for AS 100. The hold time is three times the hello interval by default, but here it is explicitly set.

Answer

EIGRP will send hello packets every 45 seconds and wait 15 seconds.

Answer

EIGRP will use the default hello interval of 5 seconds and hold time of 15 seconds.

Answer

EIGRP will not form neighbor adjacencies because the hold time is not a multiple of the hello interval.

Question 7

What is the default EIGRP hello interval on a point-to-point serial interface?

Accepted Answer

5 seconds. EIGRP uses a default hello interval of 5 seconds on most interfaces, including point-to-point serial links. On NBMA interfaces like Frame Relay, the default may be different, but for point-to-point it is 5 seconds.

Answer

10 seconds

Answer

30 seconds

Answer

60 seconds

Question 8

A network engineer configures SNMPv3 with authentication and privacy on a router. The NMS can poll the router successfully. After a router reload, the NMS fails to poll the router, but the SNMP configuration is unchanged. Which is the most likely explanation?

Accepted Answer

The SNMP engine ID changed after the reload because it was not explicitly configured, causing authentication keys to be recalculated.. The SNMP engine ID is generated based on the router's MAC address or a configured value. If the router's MAC address changes (e.g., due to a hardware change) or if the engine ID is not explicitly configured, the engine ID may change after reload, causing key mismatch.

Answer

The router lost its SNMP configuration due to a failed startup config.

Answer

The NMS's SNMPv3 credentials were deleted during the reload.

Answer

The router's SNMP process failed to start after reload.

Question 9

Which of the following is a mandatory condition for a route to be considered a feasible successor in EIGRP?

Accepted Answer

The reported distance must be less than the feasible distance.. A feasible successor must have a reported distance (RD) less than the feasible distance (FD) of the successor. This ensures the path is loop-free.

Answer

The metric must be equal to the successor's metric.

Answer

The next-hop router must be directly connected.

Answer

The route must be learned from the same AS.

Question 10

An engineer configures SNMPv2c with a read-write community string 'private' on a router. The NMS can poll interface statistics and modify some objects, but when trying to shut down an interface via SNMP, the NMS receives an error. Which is the most likely explanation?

Accepted Answer

The interface is a loopback interface, which does not support the ifAdminStatus transition to down via SNMP.. SNMP write access to certain objects may be restricted by the MIB implementation or by the view. The ifAdminStatus object is writable, but some interfaces (e.g., loopback) may not support being shut down via SNMP, or the view may exclude that object.

Answer

The community string 'private' is read-only, not read-write.

Answer

The NMS is using the wrong OID for the interface.

Answer

The router requires SNMPv3 for write operations.

Question 11

Which TWO commands can be used to troubleshoot EIGRP route redistribution issues when routes are not appearing in the routing table? (Choose TWO.)

Accepted Answer

show ip protocols. The 'show ip protocols' command confirms redistribution configuration and route filters. The 'show ip eigrp topology all-links' displays all known routes, including those that may be suppressed by metrics or filters. The other options are either for OSPF or do not show redistribution-specific information.

Answer

show ip route

Answer

show ip ospf database

Answer

debug ip routing

Question 12

A network engineer configures SNMPv3 with authentication only (no privacy) on a router. The NMS can poll the router successfully. Later, the engineer adds the 'priv' option to the user configuration. The NMS now fails to poll the router. Which is the most likely explanation?

Accepted Answer

The NMS is still configured with the old credentials that do not include the privacy protocol and key.. When privacy is added to an SNMPv3 user, the NMS must be configured with the privacy protocol and key. If the NMS is still using the old credentials without privacy, authentication may succeed but privacy decryption fails, causing the response to be discarded.

Answer

The router's SNMP engine ID changed when the user was modified.

Answer

The privacy protocol (e.g., AES) is not supported on the router.

Answer

The NMS must restart to recognize the new security level.

Question 13

An enterprise network uses EIGRP with route summarization. Router R1 has the following configuration: interface GigabitEthernet0/0 ip summary-address eigrp 100 10.1.0.0 255.255.252.0. Router R2, connected to R1 via GigabitEthernet0/0, shows: 'show ip route eigrp' includes 10.1.0.0/22 but not the more specific route 10.1.1.0/24. Hosts in subnet 10.1.1.0/24 are unreachable from R2. What is the root cause?

Accepted Answer

R1's summary address 10.1.0.0/22 includes the 10.1.1.0/24 subnet, so R1 suppresses the more specific route, and R2 only learns the summary. This is expected behavior, but if the summary does not match the actual network, reachability fails.. The summary address 10.1.0.0/22 is being advertised by R1, which suppresses the more specific 10.1.1.0/24 route. This is a common issue when summarization is configured on an interface without proper null0 route or when the summary is too broad, causing loss of reachability to specific subnets.

Answer

R1 has a missing null0 route for the summary, causing it to not advertise the summary correctly.

Answer

The summary address 10.1.0.0/22 is configured on the wrong interface; it should be on the interface facing the internal network.

Answer

R2 has a route filter that blocks the 10.1.1.0/24 route.

Question 14

An engineer configures SNMPv2c with a community string 'public' and an ACL that permits only the NMS IP address. The NMS can poll the router successfully. Later, the engineer adds a second community string 'monitor' with a different ACL that permits a second NMS. The first NMS now fails to poll. Which is the most likely explanation?

Accepted Answer

The ACL for the 'public' community string was accidentally removed when the 'monitor' community string was added.. When multiple community strings are configured, the router matches the community string from the request. If the first NMS sends the community string 'public', it should still work. However, if the ACL for 'public' is inadvertently removed or modified, or if the second community string's ACL inadvertently blocks the first NMS, issues can arise.

Answer

The second community string 'monitor' has a higher priority and overrides the first.

Answer

The router can only support one community string at a time.

Answer

The first NMS must be reconfigured to use the 'monitor' community string.

Question 15

A network redistributes EIGRP into OSPF. Router R1 is a redistribution point with configuration: router eigrp 100 redistribute ospf 1 metric 10000 100 255 1 1500. Router R2, an OSPF router, shows: 'show ip route ospf' includes some EIGRP routes but with higher cost than expected. Traffic from R2 to those networks takes suboptimal paths. What is the root cause?

Accepted Answer

The redistributed metric values are too high, causing EIGRP to calculate a high composite metric, making these routes less preferred than other paths.. Redistribution metrics must match the destination routing protocol's metric structure. For EIGRP, the metric includes bandwidth, delay, reliability, load, and MTU. If the redistributed metric is too high (e.g., large bandwidth value), EIGRP may calculate a composite metric that is less preferred, leading to suboptimal routing.

Answer

OSPF is using a different metric type (E1 vs E2) that affects path selection.

Answer

R1 has a route-map that modifies the metric during redistribution, but it is not applied.

Answer

The redistribution is one-way; OSPF routes are not being redistributed back into EIGRP, causing asymmetry.