Cisco Exam 300-410 Topic 11 Question 105 Discussion

Actual exam question for Cisco's 300-410 exam

Question #: 105
Topic #: 11

Refer to the exhibit.

R1 has a route map configured, which results in a loss of partial IPv6 prefixes for the BGP neighbor, resulting in service degradation. How can the full service be restored?

AThe neighbor requires a soft reconfiguration, and this will clear the policy without resetting the BGP TCP connection.

BThe prefix lit requires all prefixes that R1 is advertising to be added to it, and this will allow additional prefixes to be advertised.

CThe route map requires a deny 20 statement without set conditions, and this will allow additional prefixes to be advertised.

DThe route map requires a permit 20 statement without set conditions, and this will allow additional prefixes to be advertised.

Show Suggested Answer

Suggested Answer: A

In OSPF (Open Shortest Path First), the MTU (Maximum Transmission Unit) size must match on both sides of a link for OSPF neighbors to form an adjacency12.If the MTU sizes do not match, the OSPF adjacency will not form, and the routers will not become neighbors12.

In this case, R1 cannot establish a neighbor relationship with R2.One possible reason for this could be a mismatch in the MTU size on the interfaces of R1 and R212.

To resolve this issue, you can configure themtu ignorecommand on the interfaces of R1 and R2 (Option A).This command allows OSPF to ignore the MTU size when determining if it can form an adjacency with a neighbor12.This means that even if the MTU sizes do not match, OSPF will still form an adjacency, and R1 and R2 will become neighbors12.

OSPF MTU Mismatch - NetworkLessons.com

Understanding OSPF MTU Mismatch Conditions and Solutions - Cisco

by Alana at Jan 10, 2025, 05:52 AM

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29 days ago

The soft reconfiguration option seems like the quickest and cleanest way to restore full service without interrupting the BGP connection.

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Bettina

2 days ago

C) I think adding a deny statement to the route map without set conditions might also help.

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Ashley

5 days ago

A) That could work too, but the soft reconfiguration seems like the safer option.

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Breana

6 days ago

B) But wouldn't adding all prefixes that R1 is advertising to the prefix list also work?

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Annice

15 days ago

A) The neighbor requires a soft reconfiguration, and this will clear the policy without resetting the BGP TCP connection.

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