[c-nsp] BGP inbound route maps

[steve at telecomplete.co.uk]

Hi,
 google for regex if you want tutorials..

you originally have:
 ip as-path access-list 77 permit ^ABCD$
 ip as-path access-list 77 permit ^(ABCD_)+[0-9]+$
 ip as-path access-list 77 permit ^(ABCD_)+[0-9]+[0-9]+$

So, yours says as-paths that are either the peer or multiple prepends of the peer plus another ASN. The key thing is you miss the spacer ("_") so if you wanted to get one or two other ASNs in the path you wont match it, only one.

What is it you want exactly?

Having:
 ip as-path access-list 77 permit ^(ABCD_)+$
 ip as-path access-list 77 permit ^(ABCD_)+_[0-9]+$
 ip as-path access-list 77 permit ^(ABCD_)+_[0-9]+_[0-9]+$

will get you the peer ASN once or multiple times, plus 0, 1 or 2 ASNs after it which I think is what you want?

Steve

On Thu, Sep 28, 2006 at 04:34:37PM +0800, Kanagaraj Krishna wrote:
> Hi,
>     What does the added expressions mean? 
> 
> +_[0-9]+_.*    
> 
> Are there any proper tutorial or manual for this expressions? Most of the stuff that I found have only basic examples. Thanks.
> 
> Regards,
> Kana
>   ----- Original Message ----- 
>   From: hjan 
>   To: Kanagaraj Krishna 
>   Sent: Saturday, September 16, 2006 5:09 PM
>   Subject: Re: [c-nsp] BGP inbound route maps
> 
> 
>   From: "Kanagaraj Krishna" <kanagaraj at aims.com.my>
>   > Hi,
>   >   We are trying to set local preference 90 for specific inbound routes 
>   > only.
>   > The specific routes are:
>   >...............
>   > neighbor xxx.xxx.xxx.xxx remote-as ABCD
>   > neighbor xxx.xxx.xxx.xxx route-map test-inbound in
>   > neighbor xxx.xxx.xxx.xxx route-map test-outbound out
>   >
>   > ip as-path access-list 77 permit ^ABCD$
>   > ip as-path access-list 77 permit ^(ABCD_)+[0-9]+$
>   > ip as-path access-list 77 permit ^(ABCD_)+[0-9]+[0-9]+$
>   >
> 
>   Try
>   ip as-path access-list 77 permit ^(ABCD_)+[0-9]+_[0-9]+_.*
>   as your third statement.
> 
>   Regards,
>   Gianluca
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-- 
Stephen J. Wilcox
BSc (Hons).  CCIE #10730
Technical Director, Telecomplete
http://www.telecomplete.co.uk/