From: John Matus (jmatus@pacbell.net)
Date: Mon Jul 04 2005 - 20:46:20 GMT-3
this is an interesting question and one that i did not get untill i studied
regex in more detail. i will tell you now, it is not enuf to memorize just
how to do this particular questing.....you need to know the WHY and HOW this
one works. the one that kumar show's is an Internetwork Experts example
(i'm guessing kumar) and is supposed to work (i tried this one a few times
and never got it to work.
you can also break this down into a few simpler statements to satify the
question.
ip as-path access-l 10 permit ^54$
ip as-path access-l 10 permit ^54_[0-9]+
this will match as-path 54 as well as 1 instance of 54 and a directly
connected neighbor.
you can also use
ip as-path access-l 10 permit ^54_[0-9]*$
this will match as path 54 AND zero or more instances of a directly
connected neighbor.
both examples satisfy the requirements. but like i said, it is not enuf to
memorize the question so much is it is understanding the answer!
Regards,
John D. Matus
MCSE, CCNP
Office: 818-782-2061
Cell: 818-430-8372
jmatus@pacbell.net
----- Original Message -----
From: "Kumar, Manoj" <manoj.kumar@citigroup.com>
To: "Sheikh Rahman" <Sheikh.Rahman@uk.didata.com>; <ccielab@groupstudy.com>
Sent: Monday, July 04, 2005 12:43 PM
Subject: RE: as-path
> Here is my try...
>
> ip as-path access-list 10 permit ^54(_[0-9]+)?$
>
> Regards,
> Manoj
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Sheikh Rahman
> Sent: Monday, July 04, 2005 10:36 PM
> To: ccielab@groupstudy.com
> Subject: as-path
>
>
> Hello There,
>
> Does any one know how to filter bgp prefix using as-path advertised from
> as 54 and its directly connected as
>
> Thanks
>
> Sheik
>
>
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