Route Filtering with prefix list.

cms819

I am a little confused with this topic.

If you're matching a 10.0.0.0/16 le 22

does this mean any network address in between those subnetmaks??

so any network address range from the/16 through /22 will be matched?
example from the /22 network address 10.0.0.0, 10.0.4.0, etc will be matched?
example from the /17 network 10.0.0.0, 10.0.128.0 will be matched?

fredrikjj

Yes. The first 16 bits of the prefix must be 10.0 and the mask must be 16,17,18,19,21 or 22.

networker050184

The first 16 bits must match. So anything with 10.0 in the first two octets. Now you say the length must be less than or equal to /22.

So let's take 10.0.1.0/21 for example. The first 16 bits match good to go. No is it less than or equal to /22? Yep! It's a match.

10.1.1.0/21? Nope first 16 bits don't match. 10.0.1.0/23? Nope, first 16 buts match but prefix length is not less than or equal to /22.