Vincent, I'm fairly certain it can match a range, just as you yourself posted you could do. There is no difference between using a range to find 0-9, than there is finding 64512-65535. So your line would look something like this: ip as-path access-list 150 permit _[64512-65535]$ -Andy ----- Original Message ----- From: "Vincent Gillet" <vgi@zoreil.com> To: <nanog@merit.edu> Sent: Friday, January 17, 2003 10:45 AM Subject: As-Path filtering based on ranges, not regex

Hi,

I would like to filter bgp updates based on AS origin.

I know that i can match origin with regex as :

_1239$

In fact, i would like to match as-path that originate from ASes from 856 to 1239.

pseudo regex would be something like : _[856..1239]$

Juniper has this feature. Cisco does not AFAIK. Purpose is try matching AS originated from Ripe/Apnic blocks. The only way to do that would be to use many as-path that match each digits :-((

This is the way i already do to match bogus ASes :

ip as-path access-list 150 permit

_(6451[2-9]|645[2-9][0-9]|64[6-9][0-9][0-9])_

ip as-path access-list 150 permit _(65[0-4][0-9][0-9]|655[0-2][0-9]|6553[0-5])_

This is not very nice.

For Juniper :

as-path PRIVATE-DENY ".* (64512-65535) .*";

This is much clearer.

Does anybody heard about "as-range" feature on Cisco box ?

Thanks

Vincent.