300-410 Practice Test 47 — 15 Questions

Question 1

BGP attribute manipulation causes unexpected path selection. Router R1 and R2 are eBGP peers. R1 receives prefix 172.16.0.0/16 from R2 with MED 50 and from another peer R3 with MED 100. R1 has configuration: 'route-map SET-MED permit 10 set metric 200' applied to neighbor R2 inbound. R1 shows 'show ip bgp 172.16.0.0' output: 'BGP routing table entry for 172.16.0.0/16, version 2, Paths: (2 available, best #2) Path #1: from R2 with MED 200, Path #2: from R3 with MED 100'. The best path is via R3, but the network expects R2 to be preferred. What is the root cause?

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

Accepted Answer

The 'bgp always-compare-med' command is missing, causing MED to be ignored for paths from different ASes.. BGP best path selection uses MED only if paths are from the same AS (if 'bgp always-compare-med' is not configured). Since R2 and R3 are different ASes, MED is not compared; instead, the next tie-breaker (e.g., IGP metric to next-hop) selects R3. The route-map sets MED on R2's routes, but it does not affect the comparison because of AS path difference.

Answer

The route-map SET-MED should be applied outbound on R2, not inbound.

Answer

R2's next-hop is unreachable via IGP, causing R1 to ignore R2's path.

Answer

R1 has 'bgp bestpath med missing-as-worst' configured, causing missing MED to be treated as worst.

Question 2

A network engineer is troubleshooting a redistribution issue between OSPF and EIGRP. Router R3 is redistributing OSPF routes into EIGRP, but some OSPF external routes are not appearing in the EIGRP topology table. The engineer checks the redistribute command under EIGRP and sees a route-map named RM-OSPF that uses a prefix-list to match specific prefixes. The missing routes are permitted by the prefix-list. What is the most likely cause?

Accepted Answer

The route-map is missing a 'set metric' command; EIGRP requires a metric for redistributed routes.. The route-map may have a 'set metric' command that is misconfigured, or the route-map may be missing the 'set metric' command entirely, causing EIGRP to reject the route because it requires a metric for redistributed routes. Alternatively, the route-map might have a 'match route-type' that excludes external type-2 routes.

Answer

The prefix-list is using the wrong sequence number and is being overridden by a later deny statement.

Answer

The OSPF routes are type-5 LSAs, which cannot be redistributed into EIGRP.

Answer

The route-map is applied to the OSPF process instead of the EIGRP process.

Question 3

A network engineer runs the following command on Router R1:

R1# show snmp statistics

SNMP packets input: 150
    Bad SNMP version errors: 0
    Unknown community name: 25
    Illegal operation for community name: 0
    Encoding errors: 0
    Number of requested variables: 300
    Number of altered variables: 0
    Get-request PDUs: 120
    Get-next PDUs: 30
    Set-request PDUs: 0
SNMP packets output: 200
    Too big errors: 0
    No such name errors: 10
    Bad values errors: 0
    General errors: 0
    Response PDUs: 200
    Trap PDUs: 0

Based on this output, which statement is correct?

Accepted Answer

There are 25 SNMP requests with invalid community strings.. The 'Unknown community name: 25' counter indicates that 25 incoming SNMP packets contained a community string that did not match any configured community on Router R1. This means those requests were rejected due to invalid community strings, making option A correct.

Answer

The router has sent 150 trap PDUs.

Answer

There were 10 set requests that failed due to bad values.

Answer

The router received 200 SNMP packets.

Question 4

Examine this configuration on router R1:

crypto isakmp policy 10
 encryption aes 256
 authentication pre-share
 group 14
 lifetime 86400
!
crypto isakmp key cisco123 address 192.168.1.2
!
crypto ipsec transform-set TSET esp-aes 256 esp-sha-hmac
 mode tunnel
!
crypto map CMAP 10 ipsec-isakmp
 set peer 192.168.1.2
 set transform-set TSET
 match address 101
!
interface GigabitEthernet0/1
 ip address 192.168.1.1 255.255.255.0
 crypto map CMAP
!
access-list 101 permit ip 10.1.1.0 0.0.0.255 10.2.2.0 0.0.0.255

What is missing from this configuration to ensure the tunnel works correctly?

Accepted Answer

Nothing is missing; the configuration is correct.. The configuration is complete for a site-to-site IPsec VPN. ISAKMP policy 10 specifies AES-256 encryption, pre-shared key authentication, Diffie-Hellman group 14, and a lifetime of 86400 seconds (the default is 86400, so explicitly setting it is fine). The crypto map CMAP binds the transform set TSET (AES-256, SHA-HMAC) to peer 192.168.1.2 and matches interesting traffic via access-list 101 (10.1.1.0/24 to 10.2.2.0/24). The interface GigabitEthernet0/1 applies the crypto map. A route to the remote LAN is not required because IPsec encrypts traffic based on the crypto ACL; routing only needs to reach the peer's public IP (192.168.1.2), which is directly connected on the same subnet.

Answer

A route to the remote LAN 10.2.2.0/24 is missing.

Answer

The ISAKMP policy needs a 'lifetime' value.

Answer

The transform set should include 'mode transport' for site-to-site.

Question 5

A router has CoPP configured with a class-map that matches OSPF traffic and polices it to 2000 pps. The router is also configured with an OSPF distribute-list in to filter routes. After applying CoPP, OSPF neighbors form, but routes from a specific neighbor are missing. The distribute-list permits all routes. Which is the most likely explanation?

Accepted Answer

CoPP drops OSPF LSU packets, preventing route installation, while hello packets still form the adjacency.. OSPF uses Hello packets to establish and maintain neighbor adjacencies, but route information is exchanged via Link State Update (LSU) packets. The CoPP policy matches OSPF traffic and polices it to 2000 pps, which can drop LSU packets if the rate is exceeded, preventing route installation while allowing enough Hello packets to keep the adjacency up. The distribute-list permits all routes, so it is not the cause of the missing routes.

Answer

The distribute-list is applied incorrectly and blocks all routes.

Answer

OSPF uses TCP, and CoPP only polices UDP.

Answer

The CoPP policy is applied to the wrong control plane subinterface.

Question 6

An engineer configures iBGP between two routers in the same AS. The routes learned via iBGP are not being installed in the routing table, even though the next-hop is reachable. The IGP is OSPF and the routes are present in the BGP table. Which is the most likely explanation?

Accepted Answer

The BGP synchronization rule is enabled, and the IGP does not have a route for the same prefix.. BGP synchronization rule (disabled by default in modern IOS) requires that for a route learned via iBGP to be considered valid, the same prefix must be present in the IGP routing table. If synchronization is enabled and the IGP does not carry the prefix, the route is not installed.

Answer

The next-hop-self command is missing on the iBGP neighbor configuration.

Answer

The administrative distance of iBGP (200) is higher than OSPF (110), so OSPF routes are preferred.

Answer

The BGP table indicates the route is valid but the best path selection fails due to missing MED.

Question 7

An engineer configures route summarization in OSPF using the 'area range' command. After configuration, some routes are missing from the routing table of other routers. Which is the most likely explanation?

Accepted Answer

The 'area range' command is configured with the 'not-advertise' keyword, suppressing the summary.. The 'area range' command in OSPF creates a summary route that is advertised as a Type 3 LSA. However, if the 'not-advertise' keyword is used, the summary route is suppressed. Additionally, if the summary route is more specific than the component routes, it may be rejected by the receiving router due to OSPF's route selection rules. Another edge case is that the summary route may be created but the component routes are still advertised individually if the 'advertise' keyword is not explicitly used (default is advertise).

Answer

The summary route is being filtered by a distribute-list on the receiving router.

Answer

The component routes are not present in the OSPF database.

Answer

The summary route is being advertised with a metric that is too high.

Question 8

snmp-server enable traps
snmp-server host 192.168.1.100 traps version 2c public
snmp-server host 192.168.1.200 informs version 2c public

What is the effect of this configuration?

Accepted Answer

Traps are sent to 192.168.1.100 and informs are sent to 192.168.1.200.. The configuration explicitly uses the 'traps' keyword for 192.168.1.100 and the 'informs' keyword for 192.168.1.200. In SNMP, the 'snmp-server host' command defines the destination and type of notification; 'traps' are unacknowledged UDP messages, while 'informs' are acknowledged (requiring a response from the receiver). Therefore, traps are sent to 192.168.1.100 and informs to 192.168.1.200, making option A correct.

Answer

Both hosts receive traps.

Answer

Both hosts receive informs.

Answer

Only traps are enabled; informs require SNMPv3.

Question 9

Which TWO commands can be used to verify the configured logging destinations on a Cisco IOS-XE device? (Choose TWO.)

Accepted Answer

show logging. The 'show logging' command displays the current state of logging, including configured logging destinations such as console, monitor, buffer, and syslog server addresses. The 'show running-config | include logging' command filters the running configuration to show only lines containing 'logging', which explicitly lists all logging destination configurations, including server IPs and logging levels. Both commands are valid for verifying configured logging destinations on Cisco IOS-XE devices.

Answer

show log

Answer

show syslog

Answer

show debug

Question 10

Which TWO commands would a network engineer use to verify OSPFv2 neighbor state and adjacency issues on a Cisco IOS router? (Choose TWO.)

Accepted Answer

show ip ospf neighbor. The 'show ip ospf neighbor' command displays the state of all OSPF neighbors, while 'debug ip ospf adj' provides real-time adjacency events. 'show ip route ospf' shows routes, not neighbor states; 'show ip ospf interface' shows per-interface details but not neighbor states directly; 'show ip protocols' displays routing process info, not neighbor states.

Answer

show ip route ospf

Answer

show ip ospf interface

Answer

show ip protocols

Question 11

An engineer configures uRPF strict mode on an interface that is part of an IPv6 BGP multihoming setup with two upstream providers. The router receives BGP routes from both providers and has equal-cost paths to some destinations. Traffic from the router to those destinations is intermittently dropped. Which is the most likely explanation?

Accepted Answer

ECMP causes asymmetric routing where packets from the same source may arrive on different interfaces, violating uRPF strict mode's single-interface check.. With uRPF strict mode enabled, the router checks that the source address of an incoming packet matches a route in the FIB and that the incoming interface is the same as the interface used to reach that source. In an ECMP scenario with two upstream providers, traffic from the router to a destination may be load-balanced across both links, but return traffic from that destination may arrive on a different interface than the one uRPF expects. This asymmetric routing causes uRPF strict mode to drop the packets, as they fail the single-interface check.

Answer

BGP routes are not installed in the routing table, so uRPF has no entry to check.

Answer

The router has 'ipv6 cef' disabled, causing uRPF to fail.

Answer

The upstream providers are using different AS paths, causing BGP to not install equal-cost paths.

Question 12

What is the default administrative distance for a route learned via the Routing Information Protocol next generation (RIPng)?

Accepted Answer

120. RIPng, the IPv6 version of RIP, uses the same default administrative distance as RIPv2, which is 120.

Answer

110

Answer

100

Answer

170

Question 13

Router R7 is part of an MPLS VPN network. It has multiple VRFs. The NMS is in the global routing table and needs to poll SNMP from devices in VRF BLUE. The configuration includes: snmp-server community public RO, snmp-server vrf BLUE community public RO. However, the NMS cannot poll the loopback interface of a router in VRF BLUE. The NMS can poll R7's global interfaces. What is the root cause?

Accepted Answer

The NMS is trying to poll a device in VRF BLUE, but the SNMP agent on R7 is not configured to respond to SNMP requests for that VRF because the 'snmp-server vrf' command is missing the 'community' keyword or the VRF is not properly associated with the SNMP process.. The NMS can poll global interfaces but not VRF BLUE interfaces because the SNMP agent on R7 is not properly configured to respond to SNMP requests for that VRF. The command 'snmp-server vrf BLUE community public RO' is correct, but the root cause is that the 'snmp-server vrf' command must be associated with the SNMP process, and if the VRF is not properly linked (e.g., missing the 'community' keyword or the VRF is not defined in the SNMP context), the agent will not process SNMP requests for that VRF. This isolates the VRF from SNMP polling, while global interfaces remain accessible.

Answer

The loopback interface of the device in VRF BLUE is not advertised into the VRF's routing table.

Answer

The SNMP community string 'public' is not allowed in VRF BLUE due to an ACL.

Answer

The NMS is using SNMPv3, but the VRF configuration only supports v2c.

Question 14

Which TWO configuration steps are required to use IP SLA for tracking an object in a routing protocol like EIGRP? (Choose TWO.)

Accepted Answer

Configure an IP SLA operation (e.g., icmp-echo).. To use IP SLA for routing protocol tracking, you must first configure an IP SLA operation (e.g., ICMP echo) and then create a tracking object that references the IP SLA operation. The tracking object is then used in the routing protocol configuration (e.g., 'track 1 ip sla 1 reachability'). Configuring a static route or a prefix-list is not required for tracking itself. The 'ip sla schedule' is needed to start the operation, but the question asks for steps to use it for tracking, so the tracking object and its reference are key.

Answer

Configure a static route pointing to the tracked interface.

Answer

Apply a prefix-list to filter routes based on the tracking object.

Answer

Schedule the IP SLA operation with the 'ip sla schedule' command.

Question 15

What is the maximum number of source ports that can be monitored in a single SPAN session on a typical Cisco Catalyst switch?

Accepted Answer

64. A single SPAN session can monitor up to 64 source ports (or source VLANs, but not both in the same session). This is a hardware limitation on most Catalyst switches.

Answer

16

Answer

32

Answer

128