Re: ASN to prefix list

[Hans Kokx <skipmeister123 () gmail com>]

In trying to clarify my question, I believe I had an "uh, duh" moment.  If I'm trying to verify that an IP or prefix is 
part of an AS, I can simply run:

10310   | 195.69.144.0     | 195.69.144.0/22     | NL | YAHOO-1 - Yahoo!
[09:23 AM] hkokx@hkokx ~/Desktop $ awhois 8.8.8.8
AS      | IP               | BGP Prefix          | CC | AS Name
15169   | 8.8.8.8          | 8.8.8.0/24          | US | GOOGLE - Google Inc.


and check the AS to see if it matches a given prefix.  I must've been tired for not catching that before :(

I don't think there's any *need* to grab a full list of prefixes for an AS to accomplish this task.
-- 
Hans Kokx


On Friday, March 29, 2013 at 7:56 AM, Michael Douglas wrote:

> If you know Cisco IOS at all you could query a public route server for whatever command output you could want.  
> Easily scriptable with expect.
>
> This project maintains a bunch of routers with open CLI access for show commands, and full internet BGP tables from 
> multiple providers: http://www.routeviews.org/
>
> Typically one would use a regex for the AS number & AS path.
>
> route-views>sh ip bgp | inc ?
>   LINE  Regular Expression
>
> show ip bgp | inc _701$  <-this gives you all the prefixes originated with AS 701 (UUNet) at the end of the AS path.
>
> I'm not sure what it is you're trying to accomplish, or if this would even be an appropriate method.  AS path 
> filtration can get pretty complex on the internet. Customers may have their own AS number "C" behind their ISP "B".  
> And ISP "A" may be in front of ISP "B" in the AS path.
>
> A B C <-AS path.  Depending on with AS you want to see prefixes from, which could be multiple ones, the regex syntax 
> is going to be different.
>
> _B_ <- prefixes transiting AS B
> _C$ <- prefixes originating from AS C; which would be a subset of what is transiting B  
>
> This goes into the syntax and issues with BGP AS path filtration with regex: http://blog.ine.com/tag/as-path/
>
> Actually, the robtex swiss army knife might be a lot easier to use, but it's web based.
>
> http://www.robtex.com/  AS701 example http://as.robtex.com/as701.html
>
> Regards,
> michael.douglas<at>ieee.org (http://ieee.org) 
> ccie #26817 || cissp-issap #69713
>
> _______________________________________________
> Pauldotcom mailing list
> Pauldotcom () mail pauldotcom com (mailto:Pauldotcom () mail pauldotcom com)
> http://mail.pauldotcom.com/cgi-bin/mailman/listinfo/pauldotcom
> Main Web Site: http://pauldotcom.com


_______________________________________________
Pauldotcom mailing list
Pauldotcom () mail pauldotcom com
http://mail.pauldotcom.com/cgi-bin/mailman/listinfo/pauldotcom
Main Web Site: http://pauldotcom.com