nanog mailing list archives
Re: As-Path filtering based on ranges, not regex
From: "Andy Johnson" <andyjohnson () ij net>
Date: Fri, 17 Jan 2003 12:10:59 -0500
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.
Current thread:
- As-Path filtering based on ranges, not regex Vincent Gillet (Jan 17)
- Re: As-Path filtering based on ranges, not regex Andy Johnson (Jan 17)
- Re: As-Path filtering based on ranges, not regex Brett Frankenberger (Jan 17)
- Re: As-Path filtering based on ranges, not regex Andy Johnson (Jan 17)