Follow me on twitter: https://twitter.com/CCNADailyTIPS
Prefix-lists are used to match on prefix and prefix-length pairs. Normal prefix-list syntax is as follows: ip prefix-list LIST permit w.x.y.z/len Where w.x.y.z is your exact prefix And where len is your exact prefix-length “ip prefix-list LIST permit 220.127.116.11/24” would be an exact match for the prefix 18.104.22.168 with a subnet mask of 255.255.255.0. This does not match 22.214.171.124/24, nor does it match 126.96.36.199/32, nor anything in between. When you add the keywords “GE” and “LE” to the prefix-list, the “len” value changes its meaning. When using GE and LE, the len value specifies how many bits of the prefix you are checking, starting with the most significant bit.
A distribute-list is used to control routing updates either coming TO your router or leaving FROM your router. Distribute-lists work on a variety of different IOS routing protocols. Because of that, learning how to use distribute-lists is very valuable.