>Thanks for your reply Nigel. After all my unsuccessful variations of >regular expressions, I came to the same conclusion. I did however get a >reply from a guy that said he knew how to do it!! I am waiting for his >response as we speak.
I know you gave some examples, but what is the behavior you are trying to cause? What is the desired effect of removing AS200 from the path? I suppose I'm wondering if there's a different way to solve the problem, and I don't yet really understand the problem. By understanding the problem, I mean what the reason is you want to remove an AS. Actually, there may be some ways to do it with AS-SET aggregation, but these tend to be ugly. > > >----- Original Message ----- >From: "Nigel Roy" >To: >Cc: "fwells12" >Sent: Thursday, November 29, 2001 7:33 AM >Subject: Re: BGP regular expressions > > >> I haven't seen anyone else answer so I thought I would put you out of your >> misery. >> >> In short no you can't. You can identify any individual part of your AS >path >> with all sorts of wonderful regular expressions but the only thing IOS >> allows you to do to change an AS path is to add or "prepend" AS numbers to >> it. It would be potentially dangerous to remove AS numbers from the path >as >> the AS path is used in loop prevention. >> >> Nigel Roy CCIE #1405 >> >> ----- Original Message ----- >> From: "fwells12" >> To: >> Sent: Wednesday, November 28, 2001 9:46 PM >> Subject: BGP regular expressions >> >> >> > I have been playing with regular expressions but I have not found one >that >> > will do this yet -if there is one... >> > >> > I want to take a particular AS OUT of an as path? Lets say you have >some >> > routes that traverse the ASs' 100 200 300 400 500 on their way to a BGP >> > speaker. I would like to be able to use one of the routers in that path >> to >> > take its own AS out of the path. For example, using the above AS path, >> can I >> > make Router200 take its own AS (200) out of path it advertises to >> downstream >> > BGP speakers. >> > >> > The result I want is that Router500 (furthest downstream bgp speaker) >> see's >> > networks on Router100 with the following AS path: 100 300 400 500. Can >> this >> > be done, even though AS 200 is actally part of the physical route? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27721&t=27721 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
