Prefix List Quiz

Ok, so, think you are a prefix list wiz?

1. ip prefix-list MatchList permit 192.168.0.0/16
192.168.0.0/8 NOT A MATCH
192.168.0.0/24 NOT A MATCH
192.168.0.0/16 MATCH (MUST MATCH SUBNET LENGTH EXACTLY)

2. ip prefix-list MatchListGreater permit 10.0.0.0/8 ge 24
10.0.0.0/8 NOT A MATCH
10.9.9.0/24 MATCH (matches the first 8 bits, matches the subnet length)
10.0.0.0/22 NOT A MATCH
10.0.0.0/28 MATCH
10.0.0.0/24 MATCH

3. ip prefix-list MatchListBetween permit 172.18.0.0/16 ge 20 le 24
172.18.0.0/16 NOT A MATCH
172.18.0.0/30 NOT A MATCH
172.18.1.0/24 MATCH
172.18.1.0/23 MATCH
172.18.0.0/20 MATCH



Remember -
1. If there is no ge or le, the / notation MUST MATCH the subnet mask. (basically must match your route exactly)

2. If there is a ge or le, the / notation only tells you what bits to match in the address, the le and or ge tells you what to look at for the mask.


Need to read the explanation again? Click Here