300-410 Question 80

Community Discussion

Written by other learners. Comments can disagree with the marked answer — check the official documentation when in doubt.

• Chose B1

  Way too much discussion on this one. Masks are lower or higher, highest being 32 bits. The requirement is to filter inbound routes lower than 23 bits. ge defines the minimum prefix length (i.e., more specific) le defines the maximum prefix length (i.e., less specific) ip prefix-list PL-1 deny 172.16.0.0/16 le 23 ip prefix-list PL-1 permit 0.0.0.0/0 le 32 router bgp 100 neighbor 192.168.100.2 remote-as 200 neighbor 192.168.100.2 prefix-list PL-1 in Answer B does exactly what the requirement states.

• Chose A1

  This is so poorly worded - I'd assume the question means more specific subnets if the goal is to improve convergence time.

• Chose B1

  Option B blocks any BGP routes coming from R2 that fall under the 172.16.0.0/16 network with a prefix length smaller than or equal to 23. As a result, R1 will not accept routes for subnets like 172.16.16.0/24, 172.16.3.0/24, and 172.16.4.0/24, but will accept routes for 172.16.0.0/16 with a prefix length of 23 or greater.