[afnog] Private IP Filters in bgp

[Mark Tinka]

On Saturday, May 26, 2012 08:38:38 AM Mohamed Faye wrote:

> ip prefix-list bgp-sanity-filter
> permit 0.0.0.0/0 le 32

Mohamed, the final filter in this prefix list example is too 
generous. If you keep it this way, your provider could send 
you address space longer than a /24 and you'd end up 
accepting it.

Suggest you make this "0.0.0.0/0 le 24", as a /24 is the 
"unofficial" maximum prefix length most operators are 
willing to accept, given the ever-growing DFZ, e.t.c.

You'd be surprised how many (so-called top-level) upstream 
providers aren't doing basic filtering in their own 
networks, both in the control and data planes.

Mark.