I tried with all debugs possible and that information isn't displayed. Very good question.

I don't think you can see from the originating router as the AS_PATH is being altered as it exits the router, not before.

HTH,

__

Edison.

Hello,

As far as I know people here are right, you cannot see this information in the originating router. So, unless somebody here knows better, I would suggest you checked some looking glasses to see how your routes are propagated to the Internet. Even if your router could show you the information you are looking for, the looking glass is still a better way to check things out, because it shows you how your routes are propagated further away from your own router.

I suppose that for you to be using the prepends, you have more than one BGP session over which you advertise your networks to the Internet. This means that you might have to check various looking glasses or routers in a particular looking glass to see the route with the prepends (because each router makes own choice). You might have to check a few routers the first time, but later, if need arises again, you would be more familiar and go directly to the looking glass and router that interests you.

Some looking glasses you can try are the following:

http://etabeta.noc.seabone.net/cgi-bin/lg.pl

https://www.linx.net/pubtools/looking-glass.html

http://lg.teleglobe.net/bin/lg.cgi

http://netmon.grnet.gr/lg.shtml

Kind Regards,

Maria

p.s. If you have difficulties seeing the route with the prepends, I would suggest you checked routers in different continents (in Europe and in US for example). If you cannot see it, it doesn't mean it is not out there (unless something is really wrong), but rather that probably you have to search more. Check also if your provider or one of its upstreams has a looking glass. That would be even more helpful.

Hi,

Use Looking Glass.

I always use RIPE-NCC http://www.ripe.net/cgi-bin/looking-glass

Regards,

Dandy

Rais,

In IOS, the Adj-RIB-out is not implemented as a separate entity. Attributes are rather changed as updates are sent to the neighbors. The command "show ip bgp nei a.b.c.d advertised-routes" show you the routes that are advertised to a specific peer but the attributes reflect their value in the loc-rib.

The comamnd "debug ip bgp update " will show some of the attributes but unfortunately not the as-path.

The same command with the detail keyword will dump the entire BGP update but in hex format. Not very useful unless you are very familiar with the BGP protocol and attribute codes or if you have a tool to convert the BGP hex message into something readable.

Regards,