300-410 Layer 3 Technologies Practice Test 2 — 15 Questions

Question 1

A network technician is configuring a Cisco router with a static route to a remote network. The technician wants the static route to be used only if the primary route learned via OSPF fails. Which command should be used?

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

Accepted Answer

ip route 192.168.2.0 255.255.255.0 10.0.0.2 200. A floating static route is created by assigning an administrative distance higher than that of the dynamic routing protocol. Here, setting the distance to 200 ensures the static route is only used when the OSPF route (distance 110) is unavailable. The other options either make the static route primary or set an equal distance.

Answer

ip route 192.168.2.0 255.255.255.0 10.0.0.2 90

Answer

ip route 192.168.2.0 255.255.255.0 10.0.0.2 110

Answer

ip route 192.168.2.0 255.255.255.0 10.0.0.2

Question 2

A network engineer is implementing policy-based routing (PBR) on a Cisco router. The engineer wants to route traffic from a specific subnet to a next-hop that is not in the routing table. Which action must be taken to ensure that PBR works correctly?

Accepted Answer

Configure a static route for the next-hop address.. PBR uses route-maps to forward traffic to a specified next-hop. For the next-hop to be used, it must be reachable via the routing table. If it is not, the router cannot forward the packet. Therefore, a static route for the next-hop address is necessary. This ensures that the next-hop is resolvable and the PBR policy can be applied. Without it, the route-map may be ignored or packets dropped.

Answer

Enable recursive routing for the next-hop.

Answer

Set the next-hop to the default gateway.

Answer

Configure the next-hop as a directly connected interface.

Question 3

A network engineer is configuring BGP on a Cisco IOS XE router. The engineer wants to ensure that the router prefers routes learned from a specific eBGP peer over routes learned from another eBGP peer. Which two BGP attributes can be manipulated to influence this decision? (Choose two.)

Accepted Answer

Local Preference. Weight and local preference are the first two attributes in the BGP best path selection process. Weight is Cisco-proprietary and local to the router, while local preference is shared within an AS. Both can be set on a per-neighbor basis to prefer routes from a specific eBGP peer. MED, AS_PATH, and Origin are evaluated later and are less suitable for this specific requirement.

Answer

Origin

Answer

AS_PATH

Answer

MED

Question 4

A network engineer is configuring OSPFv3 on an IPv6 network. R1 and R2 are directly connected on the same segment with the same area ID and same OSPFv3 process ID. However, they are not forming an adjacency. The engineer verifies that IPv6 unicast routing is enabled, but the neighbor state remains down. What is the most likely cause?

Accepted Answer

The OSPFv3 process is not configured with a router ID and no IPv4 addresses are present on the routers.. OSPFv3 uses a 32-bit router ID that must be unique. Unlike OSPFv2, it does not automatically use an IPv4 interface address if none exists. In an IPv6-only environment, if no IPv4 addresses are configured, the router ID must be manually set. Without a router ID, OSPFv3 does not initialize, preventing adjacency formation.

Answer

The OSPFv3 area ID is configured as a decimal value instead of dotted decimal.

Answer

The OSPFv3 network type is mismatched between the two routers.

Answer

A router ID conflict exists because OSPFv3 does not automatically select a router ID.

Question 5

A network engineer is configuring OSPFv3 on a Cisco IOS router. The engineer wants to enable OSPFv3 on an interface and ensure that it participates in the OSPFv3 process. Which command is required on the interface?

Accepted Answer

ipv6 ospf 1 area 0. In OSPFv3, interfaces are enabled for OSPFv3 using the interface command 'ipv6 ospf process-id area area-id'. This command is required for the interface to participate in the OSPFv3 process. The other options are either global commands or incorrect for OSPFv3.

Answer

ospfv3 1 ipv6 area 0

Answer

ipv6 router ospf 1

Answer

network 2001:db8::/32 area 0

Question 6

A network engineer is configuring OSPFv3 on a dual-stack router. The router has two interfaces: GigabitEthernet0/0 with IPv6 address 2001:DB8:1::1/64 and GigabitEthernet0/1 with IPv6 address 2001:DB8:2::1/64. The engineer enters the commands:

ipv6 unicast-routing
ipv6 router ospf 1
 router-id 1.1.1.1
interface GigabitEthernet0/0
 ipv6 ospf 1 area 0
interface GigabitEthernet0/1
 ipv6 ospf 1 area 0

After configuration, the router does not form any OSPFv3 neighbor adjacencies. Which action is most likely to resolve the problem?

Accepted Answer

Configure the router-id under the OSPFv3 process using the 'router-id' command.. OSPFv3 requires a router ID to form adjacencies. If no IPv4 address is configured on any interface, the router ID defaults to 0.0.0.0, and OSPFv3 will not function. Manually setting the router ID under the OSPFv3 process resolves this. The other options either are already configured or do not address the missing router ID.

Answer

Enable OSPFv3 on the interfaces using the 'ipv6 ospf 1 area 0' command under each interface.

Answer

Enable IPv6 unicast routing globally with the 'ipv6 unicast-routing' command.

Answer

Assign IPv4 addresses to the interfaces to allow OSPFv3 to use them for router ID selection.

Question 7

A network administrator is troubleshooting an EIGRP adjacency that is stuck in the ACTIVE state. The adjacency is between two routers on a LAN segment. Which two actions should the administrator take to resolve this issue? (Choose two.)

Accepted Answer

Verify that the K values configured for EIGRP match on both routers.. EIGRP adjacency issues often stem from mismatched K values or blocked multicast traffic. The K values must match for routers to become neighbors, and ACLs blocking 224.0.0.10 will prevent hello exchange. Both are common causes of adjacency problems that can lead to routes stuck in ACTIVE. The other options are either incorrect (AS number must match, timers can differ) or would prevent any adjacency rather than cause ACTIVE state.

Answer

Confirm that the hello and hold timers are mismatched.

Answer

Ensure that the autonomous system number is different on each router.

Answer

Verify that the interface is configured as passive.

Question 8

A network engineer is troubleshooting a DMVPN Phase 3 network using OSPF as the routing protocol. Spoke routers are not learning routes from other spokes via the hub. The hub is configured with 'ip nhrp redirect' and spokes with 'ip nhrp shortcut'. The engineer notices that spoke-to-spoke traffic is flowing through the hub, but OSPF adjacencies are only formed between each spoke and the hub. What is the primary reason for this behavior?

Accepted Answer

The spokes are not receiving NHRP resolution replies because the hub is not configured to redirect spoke-to-spoke traffic.. DMVPN Phase 3 enables spoke-to-spoke communication via NHRP shortcuts. The hub must be configured with 'ip nhrp redirect' to send redirect messages when it receives traffic from a spoke destined to another spoke. Spokes with 'ip nhrp shortcut' then initiate NHRP resolution to the destination spoke and install a shortcut route. Without the hub's redirect, spokes keep using the hub path.

Answer

The hub is not configured as a route reflector for OSPF, so spokes cannot exchange routes directly.

Answer

OSPF is a link-state protocol and requires full mesh adjacencies to exchange routes between spokes.

Answer

OSPF network type is set to broadcast on the tunnel interfaces, preventing spoke-to-spoke adjacencies.

Question 9

A network engineer is configuring EIGRP on a Cisco IOS XE router. The engineer wants to ensure that the router does not advertise a specific prefix to any EIGRP neighbor. Which configuration should be used?

Accepted Answer

Configure an outbound distribute-list on all EIGRP interfaces using an ACL that denies the specific prefix.. To prevent EIGRP from advertising a specific prefix, an outbound distribute-list can be applied to all EIGRP interfaces. The ACL denies the prefix and permits all others. This filters the prefix from EIGRP updates. Other methods like passive-interface or route-maps are either ineffective or more complex for this simple requirement.

Answer

Configure the 'passive-interface' command on the interface associated with the prefix.

Answer

Configure a distribute-list with an ACL that denies the prefix in the outbound direction on all EIGRP interfaces.

Answer

Configure a route-map and apply it with the 'distribute-list route-map' command in EIGRP address-family configuration mode, denying the prefix.

Question 10

A network engineer is deploying MPLS Layer 3 VPNs. The engineer needs to configure the provider edge (PE) routers to support multiple VRFs. Which two statements about VRF configuration on Cisco IOS routers are true? (Choose two.)

Accepted Answer

Each VRF maintains a separate routing table and forwarding table.. VRFs provide separate routing and forwarding tables, enabling network virtualization. Route targets control the import and export of routes between VRFs, facilitating MPLS L3VPN functionality. These two statements are true. The other options are false: VRF interfaces can have overlapping IP addresses, a VRF has a single RD, and VRF-aware services require explicit VRF specification in commands.

Answer

VRF-aware services such as ping and traceroute require the use of the 'vrf' keyword in commands.

Answer

VRF interfaces must be configured with the same IP address as the global routing table.

Answer

A single VRF can be associated with multiple route distinguishers (RDs).

Question 11

A network engineer is troubleshooting an OSPFv3 network. Router R1 is configured with `ipv6 unicast-routing` and OSPFv3 is enabled on all interfaces. R1's neighbor table shows a neighbor in EXSTART state, but the adjacency never progresses to FULL. What is the most likely cause?

Accepted Answer

Mismatched MTU on the interfaces.. In OSPFv3, the EXSTART state is part of the database exchange process where routers negotiate master/slave roles using DBD packets. If the MTU values on the interfaces differ, the routers cannot successfully exchange these packets, and the adjacency remains in EXSTART. Ensuring MTU consistency resolves this issue. Other mismatches like area ID or authentication would prevent the adjacency from reaching EXSTART in the first place.

Answer

Authentication mismatch.

Answer

Mismatched OSPFv3 area IDs.

Answer

Duplicate router IDs on the two routers.

Question 12

A network engineer is configuring OSPFv2 on a Cisco router. The router is connected to a broadcast network via GigabitEthernet0/0 and to a point-to-point serial link via Serial0/0/0. The engineer wants to minimize OSPF neighbor formation time and ensure that DR/BDR election does not occur on either interface. Which configuration should be applied?

Accepted Answer

Configure ip ospf network point-to-point on both interfaces.. Changing the OSPF network type to point-to-point on both interfaces eliminates DR/BDR election and reduces neighbor formation time because no wait timer for DR election is needed. On a broadcast interface with only two routers, this is a valid optimization. On a serial link, it aligns with the default behavior, ensuring consistent operation.

Answer

Configure ip ospf network non-broadcast on both interfaces.

Answer

Configure ip ospf priority 0 on both interfaces.

Answer

Configure ip ospf network broadcast on both interfaces.

Question 13

A network administrator is configuring a route-map to control redistribution from OSPF into EIGRP. The goal is to redistribute only routes with a tag of 100 and set their metric to bandwidth 1000, delay 100, reliability 255, loading 1, and MTU 1500. Which route-map configuration accomplishes this?

Accepted Answer

route-map REDIST permit 10
 match tag 100
 set metric 1000 100 255 1 1500. The set metric command for EIGRP takes five parameters: bandwidth, delay, reliability, loading, and MTU. The correct order is bandwidth, delay, reliability, loading, MTU. The route-map must match the tag and then set these five values. The other options either have too many parameters or use an incorrect command (metric-type) that is not valid for EIGRP.

Answer

route-map REDIST permit 10
 match tag 100
 set metric 1000 100 255 1 1500 0 0

Answer

route-map REDIST permit 10
 match tag 100
 set metric-type internal

Answer

route-map REDIST permit 10
 match tag 100
 set metric 1000 100 255 1 1500 1

Question 14

A network engineer is configuring OSPF on a Cisco IOS-XE router. The router has two interfaces in Area 0: GigabitEthernet0/0 (10.1.1.1/24) and GigabitEthernet0/1 (10.2.2.1/24). The engineer wants to ensure that OSPF uses the highest IP address of a loopback interface as the router ID, but no loopback is currently configured. Which command should the engineer use to explicitly set the OSPF router ID to 10.255.255.1?

Accepted Answer

router ospf 1
 router-id 10.255.255.1. The OSPF router ID is a 32-bit value that uniquely identifies the router within the OSPF domain. By default, it is chosen as the highest IP address among loopback interfaces, or if none, the highest IP address among active physical interfaces. To explicitly set it, the 'router-id' command under the OSPF process is used. This command is straightforward and does not require additional network statements. The other options either use invalid syntax or unnecessary commands.

Answer

router ospf 1
 router-id 10.255.255.1
 network 10.0.0.0 0.255.255.255 area 0

Answer

interface GigabitEthernet0/0
 ip ospf router-id 10.255.255.1

Answer

router ospf 1
 network 10.255.255.1 0.0.0.0 area 0

Question 15

A network engineer is troubleshooting OSPFv3 adjacency issues on a Cisco IOS XE router. The engineer suspects that OSPFv3 is not forming an adjacency because of mismatched parameters. Which two parameters must match for an OSPFv3 adjacency to form? (Choose two.)

Accepted Answer

Hello interval and dead interval. For OSPFv3 adjacencies to form, the hello interval, dead interval, and area ID must match. These parameters are included in hello packets and are checked before adjacency is established. Router priority only affects DR election and does not need to match. Authentication is only required if configured, and MTU mismatch is detected later during DBD exchange, not a hello parameter. Therefore, the two correct parameters are hello/dead intervals and area ID.

Answer

MTU

Answer

Router priority

Answer

Authentication type and key