300-410 Exam QuestionsBrowse all questions from this exam

300-410 Exam - Question 57


Refer to the exhibits. A company with autonomous system number AS65401 has obtained IP address block 209.165.200.224/27 from ARIN. The company needed more IP addresses and was assigned block 209.165.202.128/27 from ISP2. An engineer in ISP1 reports that they are receiving ISP2 routes from AS65401.

Which configuration on R1 resolves the issue?

A.

B.

C.

D.

Show Answer
Correct Answer:

The correct configuration on R1 to resolve the issue where ISP1 is receiving ISP2 routes from AS65401 is as follows: ``` access-list 10 deny 209.165.202.128 0.0.0.31 access-list 10 permit any ! router bgp 65401 neighbor 209.165.201.1 distribute-list 10 out ``` This configuration creates an access list denying the 209.165.202.128/27 IP block from being advertised to ISP1. The distribute-list is applied to outbound advertisements to ISP1, ensuring that these routes are filtered and not propagated. Using 'out' instead of 'in' is crucial since we are filtering the routes being advertised out to ISP1, not the routes being received.

Discussion

5 comments
Sign in to comment
examShark
Aug 4, 2021

Te given answer is correct

RTE
Jul 25, 2021

in answer invalid neighbour statement, but direction and access list are good

cakmamail
Aug 5, 2021

Ulan burada da mı çıktın karşıma!

Nhan
Sep 9, 2022

The given answer is correct, simple acl block the route coming in and redistribute to the ISP 1 from us

Pietjeplukgeluk
Jun 24, 2024

A seems inline with question, but the answer is not totally correct, the ACL does not permit the networks owned by as 65401, it actually permits way to much networks

SeMo0o0o0
Jul 17, 2024

A is correct