COM-407: Exam 2021 Problem 2 Q6

Hi,

In the description of the network, it is said that the BGP routers do not redistribute external BGP routes into OSPF. However, in the solution of question 6, it is said that "OSPF at V3 computes the shortest path and finds that there are two equal-cost paths, namely V3 − V5 − V4 − S3 and V3 − V1 − V2 − S2.".

Considering that every BGP router injects its BGP routes into its forwarding table, at v3, 2614:9fca:1f7c:cd56:n:k:z:h should have a next-hop field equal to s3v4 or s2v2. Can this configuration work without recursive table lookup ?

Best regards,

Ali

Re: Exam 2021 Problem 2 Q6

by Stéphan Plassart - Monday, 3 January 2022, 10:01

Dear Ali,

In the previous question, question 5, the initial network is modified such that "all other routers in AS V redistribute external BGP routes into OSPF with distance at the point of redistribution equal to 21"

This is is also the case in question 6, that's why redistribution in AS V is allowed and so you can obtain such solution.

Hope this answer your question.

Best regards,
Stéphan.