From: Victor Cappuccio (cvictor@protokolgroup.com)
Date: Fri Jun 16 2006 - 14:52:45 ART
Albert You can telnet to route-server.exodus.net or route-server.gblx.net
Any try the regular expression
IMHO the ^254_[0-9]*$, would be not correct, It works cause the AS Path has
a character like i, ? or e, and in the Reg Expression you are using the *
that Matches zero or more sequences of the character preceding the
asterisk. Also acts as a wildcard for matching any number of characters.
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fter
sv_c/ftsappx/tcfaapre.htm
I think that if you only what to match the Customer Routes from that AS your
Regular expression should look like show ip bgp reg _254(_[0-9]+)$.
To match also for the AS254 Routes and for the Customer Routes, I think you
should use _254_([0-9]+)$
Sorry for the first post It was very early morning, and Caffeine was missing
:D
Thanks
Victor.
-----Mensaje original-----
De: Albert Ip [mailto:ipwaikuen@yahoo.com.hk]
Enviado el: Viernes, 16 de Junio de 2006 01:14 p.m.
Para: Elias Chari; Victor Cappuccio
CC: ccielab@groupstudy.com
Asunto: Re: BGP AS Path Access List and Filter List Question
Hi Elias,
Thanks for your capture.
So, how about if the reg. exp. look like this?
^_254_[0-9]*$
Albert
--- Elias Chari <elias.chari@gmail.com> Uf#:
> Guys,
>
> ^254_[0-9]*$ will also match only AS 254.
>
> Sorry for the long text, it's from a public route
> server...
>
>
> 1. The first part shows the output of: sh ip bgp
> rege ^3356_ just to
> collect anything starting with 3356.
>
> 2. Second output shows that sh ip bgp regexp
> ^3356_[0-9]*$ also matches
> routes with only 3356 in the path.
>
> ===================
>
> * i8.0.0.0/9 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> *>i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i8.2.64.0/23 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> *>i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i8.3.12.0/24 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> *>i 67.17.64.89 100
> 200 0 3356 14711 i
>
> =================================
>
> * i8.0.0.0/9 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> *>i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i 67.17.64.89 100
> 200 0 3356 i
> * i8.2.64.0/23 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> *>i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i 67.17.64.89 100
> 200 0 3356 16803 i
> * i8.3.12.0/24 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> *>i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> * i 67.17.64.89 100
> 200 0 3356 14711 i
> --More--
>
>
>
> On 6/16/06, Victor Cappuccio
> <cvictor@protokolgroup.com> wrote:
> >
> > Hi Albert IMHO the Regular Expression that you
> posted will match, but it
> > will not match routes for the internal 254 Routes
> couse the _underscore_
> > that you have in the expression
> > So I think that the regular expression should be
> ^254(_[0-9]*)$
> > Just my opinion here
> >
> > Regards
> > Victor.
> >
> > -----Mensaje original-----
> > De: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com] En nombre de
> > Albert
> > Ip
> > Enviado el: Viernes, 16 de Junio de 2006 05:08
> a.m.
> > Para: ccielab@groupstudy.com
> > Asunto: BGP AS Path Access List and Filter List
> Question
> >
> > Hi All,
> >
> >
> > Two BGP routers, BB1 and R1, BB1 in AS 254 and R1
> in
> > AS 55, both connected in same LAN subnet.
> >
> > Question 1:
> >
> > In future, there will be another AS directly
> connect
> > with AS 254. Configure R1 accept BGP routes from
> BB1
> > that originate from AS 254 and any other AS
> directly
> > connected to AS 254. Limit to use one filter list
> > only.
> >
> >
> > Answer:
> >
> > R1
> >
> > ip as-path access-list 1 permit ^254_[0-9]*$
> >
> > router bgp 55
> > nei 150.100.1.254 filter-list 1 in
> >
> >
> > Is this answer correct????
> >
> >
>
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