Hard — 350-401 Practice Quiz

Question 1

Two directly connected routers, R1 (AS 65010) and R2 (AS 65020), are configured for eBGP peering using their physical interface IP addresses. The link is up and both routers can ping each other's interface, but the BGP session cycles between Idle and Active and never reaches Established. On R1 you see the neighbor configured with 'neighbor 10.0.0.2 update-source Loopback0'. R1's Loopback0 is 1.1.1.1/32 and R2 is peering to 10.0.0.1 (R1's physical interface). What is the most likely cause of the session failure?

Accepted Answer

R1 is sourcing BGP packets from Loopback0 (1.1.1.1), but R2 expects the session from 10.0.0.1, so the incoming packets do not match R2's configured neighbor address

Answer

eBGP requires the 'ebgp-multihop 2' command whenever routers are directly connected on the same subnet

Answer

The two routers are in different autonomous systems, which prevents any eBGP session from forming without a route reflector

Answer

BGP synchronization is enabled by default and must be disabled before the neighbor can reach Established

Question 2

An engineer configures eBGP between two directly connected routers, R1 (AS 100) and R2 (AS 200), using the interface IP addresses on the shared 10.1.1.0/30 link. R2 advertises 192.168.50.0/24 to R1. On R1, the BGP table shows the 192.168.50.0/24 prefix as valid but with a status of 'inaccessible' and it is not installed in the routing table. The neighbor is in the Established state and other prefixes are learned fine. What is the MOST likely cause?

Accepted Answer

R1 has no route to reach the BGP next-hop address advertised for 192.168.50.0/24, so the recursive lookup fails

Answer

The eBGP session requires the 'ebgp-multihop' command because the routers are directly connected

Answer

R2 must be configured with 'next-hop-self' for the eBGP session to install the prefix

Answer

The prefix is being filtered by an inbound distribute-list on R1

Question 3

A network engineer wants R1 to load-balance traffic across two paths toward 10.20.0.0/24. The successor route has a feasible distance of 3072000, and a feasible successor exists with a reported distance of 2560000 and a feasible distance of 4096000. Currently only the successor path is installed in the routing table. Which action will cause EIGRP to install BOTH paths for unequal-cost load balancing?

Accepted Answer

Configure 'variance 2' under the EIGRP process on R1

Answer

Configure 'maximum-paths 2' under the EIGRP process on R1

Answer

Configure 'variance 1' under the EIGRP process on R1

Answer

Lower the EIGRP hello and hold timers on both interfaces

Question 4

A network engineer manages an OSPF network with a backbone (area 0) and two normal areas (area 10 and area 20). The 10.50.0.0/24 subnet exists in area 10. Management wants to prevent this specific inter-area route from being advertised into area 20, while all other inter-area routes must continue to flow normally. On which device and using which mechanism should the engineer implement this filter?

Accepted Answer

On the ABR between area 0 and area 20, apply an area 20 filter-list using a prefix-list in the 'in' direction

Answer

On the ABR between area 0 and area 10, apply a distribute-list with an access-list on the LSA Type 1 flooding

Answer

On any internal router in area 20, apply a distribute-list in the inbound direction to drop the route from the routing table

Answer

Convert area 20 to a totally stubby area so that only a default route is injected

Question 5

An enterprise OSPF domain has an ABR connecting the backbone (area 0) to a stub-like area (area 20) that contains an ASBR redistributing static routes from a partner network. The design team wants area 20 to allow its locally originated external routes to be advertised into the rest of the OSPF domain, but block Type 5 LSAs from other ASBRs from entering area 20. Which area type must be configured on area 20 to meet both requirements?

Accepted Answer

Not-so-stubby area (NSSA)

Answer

Totally stubby area

Answer

Standard stub area

Answer

Backbone area

Question 6

A network engineer is reviewing the QoS policy on a branch router WAN interface. Voice traffic is marked EF, and the following policy-map is applied outbound:

policy-map WAN-EDGE
 class VOICE
  priority percent 20
 class VIDEO
  bandwidth percent 30
 class class-default
  fair-queue

During periods of severe WAN congestion, users report that voice quality is acceptable but a new bulk backup application (which falls into class-default) is being starved of throughput at times, while at other times video streams experience delay. What is the correct interpretation of how this policy handles traffic under congestion?

Accepted Answer

The VOICE class uses a low-latency (priority) queue that is policed to 20% of link bandwidth during congestion, guaranteeing low delay for EF traffic while capping its maximum usage.

Answer

The VOICE class is guaranteed a minimum of 20% bandwidth but can burst without limit, which is why class-default is being starved.

Answer

The VIDEO class receives strict priority over VOICE because bandwidth statements are serviced before priority statements.

Answer

All three classes share bandwidth equally through fair-queue, so the priority and bandwidth percentages are ignored under congestion.

Question 7

A network engineer has deployed VRF-lite on a Cisco IOS-XE router to separate GUEST and CORP traffic. Both VRFs must reach a shared DNS server located in a SHARED-SVCS VRF, but GUEST and CORP must remain isolated from each other. Using MP-BGP with route-target import/export on the router, which configuration approach correctly enables the shared services access while preserving isolation between GUEST and CORP?

Accepted Answer

Configure the SHARED-SVCS VRF to export its route-target and have both GUEST and CORP import it, while SHARED-SVCS imports the route-targets of both GUEST and CORP.

Answer

Configure GUEST and CORP to export the same route-target value so all three VRFs can exchange the DNS route.

Answer

Merge GUEST, CORP, and SHARED-SVCS into a single VRF and rely on ACLs to keep GUEST and CORP separated.

Answer

Configure GUEST to import CORP's route-target and CORP to import GUEST's route-target so both can reach the shared DNS server transitively.