Comments on: Understanding BGP Regular Expressions

By: Brian McGahan, CCIE #8593

Brian McGahan, CCIE #8593 — Tue, 10 Jun 2008 16:30:42 +0000

It should match the same thing. Test it on a route server to be 100% sure.

By: Nizami

Nizami — Tue, 06 May 2008 10:03:06 +0000

hi Brian. i have a question.how to match on AS and all its directly connected customers with taking into consideration the future growth.
what is the difference between theese regular expressions? Say we have AS 100.

^100(_[0-9]+)?$
and

^100_[0-9]*$
will result be the same?

By: Brian McGahan, CCIE 8593

Brian McGahan, CCIE 8593 — Thu, 10 Jan 2008 02:30:00 +0000

You need to escape the dot with a backslash. You could say 65000\.65000

By: shef

shef — Wed, 09 Jan 2008 08:16:13 +0000

yes.

2-byte AS have dot: 65000.65000 for example. Dot in regexp - any single character

By: Brian McGahan, CCIE 8593

Brian McGahan, CCIE 8593 — Tue, 08 Jan 2008 21:52:46 +0000

What is an example case of this?

By: shef

shef — Mon, 07 Jan 2008 12:28:59 +0000

And what we should do with 2-byte AS’s?
Thanks.