From: Brian McGahan (brian@cyscoexpert.com)
Date: Tue Dec 10 2002 - 22:27:30 GMT-3
Martin,
Yes, both or those expressions would work. Usually there are
many ways to solve a problem with a regular expression. Another valid
answer would be _30(3|4)$ for example.
A good way to practice your regular expressions is to try them
on a live route-server. A route-server is a dedicated box running BGP
that shows an ISP's view of the global routing table. They're most
useful to make sure that your prefixes are propagating properly
throughout the internet, but since the majority of them are cisco boxes,
you can 'show ip bgp regexp ...' to test your regular expressions.
For a listing of route-servers:
http://www.traceroute.org/#Route%20Servers
Try this one:
All routes originated in AS 10, transited AS 100, and learned
from AS 1000, in one line. Assume that the prefix could have passed
through an arbitrary amount of AS's (or not).
HTH
Brian McGahan, CCIE #8593
Director of Design and Implementation
brian@cyscoexpert.com
CyscoExpert Corporation
Internetwork Consulting & Training
Voice: 847.674.3392
Fax: 847.674.2625
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> MOLINA, MARTIN J (PBI)
> Sent: Tuesday, December 10, 2002 3:54 PM
> To: 'ccielab@groupstudy.com'
> Subject: BGP Reg Expressions
>
> Hello,
> If I wanted to construct 1 regular expression to identify routes
> originated
> by AS 303 or 304, would both of the following work:
> _(303 | 304)$
>
> _30[34]$
>
> Thanks
>
>
> Martin Molina
> Senior Network Engineer
> SBC (Pacific Bell) Internet Services
> CCNP CCDP
> desk: (925) 973-7774
> cell: (925) 216-5299
> .
.
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