Re: [c-nsp] Remove BGP AS path number number from an AS PATH
I doubt that you can do that... but if this is to influence your outgoing traffic, then I would use local-preferences. Christophe -Original Message- From: cisco-nsp-boun...@puck.nether.net [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Michalis Palis Sent: Thursday, May 28, 2009 9:49 AM To: cisco-nsp@puck.nether.net Subject: [c-nsp] Remove BGP AS path number number from an AS PATH Hello All Is their a way to remove the first AS number (not private) from an AS path? For example we are receiving a route with AS PATH 123 456 456 456 and we want to remove the 123 AS and put in the BGP table the route with AS 456 456 456 . Thanks for your reply ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Remove BGP AS path number number from an AS PATH
yup, you can't remove public AS from AS path. would you please share the idea why you wana remove it :) there are many other attributes to tweak bgp, y not u use them. BR\\ Masood I doubt that you can do that... but if this is to influence your outgoing traffic, then I would use local-preferences. Christophe -Original Message- From: cisco-nsp-boun...@puck.nether.net [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Michalis Palis Sent: Thursday, May 28, 2009 9:49 AM To: cisco-nsp@puck.nether.net Subject: [c-nsp] Remove BGP AS path number number from an AS PATH Hello All Is their a way to remove the first AS number (not private) from an AS path? For example we are receiving a route with AS PATH 123 456 456 456 and we want to remove the 123 AS and put in the BGP table the route with AS 456 456 456 . Thanks for your reply ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Remove BGP AS path number number from an AS PATH
Let's be more precise. There is no publicly known way to remove a non-private AS number from AS-path on a device running Cisco IOS ... but you could always adapt Quagga source code to your needs. As pointed out by previous replies, tweaking AS-PATH is a really bad idea. BGP has numerous other tools. Ivan http://www.ioshints.info/about http://blog.ioshints.info/ -Original Message- From: mas...@nexlinx.net.pk [mailto:mas...@nexlinx.net.pk] Sent: Thursday, May 28, 2009 6:56 PM To: Varaillon Jean Christophe Cc: cisco-nsp@puck.nether.net Subject: Re: [c-nsp] Remove BGP AS path number number from an AS PATH yup, you can't remove public AS from AS path. would you please share the idea why you wana remove it :) there are many other attributes to tweak bgp, y not u use them. BR\\ Masood I doubt that you can do that... but if this is to influence your outgoing traffic, then I would use local-preferences. Christophe -Original Message- From: cisco-nsp-boun...@puck.nether.net [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Michalis Palis Sent: Thursday, May 28, 2009 9:49 AM To: cisco-nsp@puck.nether.net Subject: [c-nsp] Remove BGP AS path number number from an AS PATH Hello All Is their a way to remove the first AS number (not private) from an AS path? For example we are receiving a route with AS PATH 123 456 456 456 and we want to remove the 123 AS and put in the BGP table the route with AS 456 456 456 . Thanks for your reply ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] Remove BGP AS path number number from an AS PATH
This list does tend to focus on public internet issues and forget that BGP is used in corporate or other non-internet environments that don't follow nice conventions and after 15+ years of corporate take-overs,mergers and demergers can often find situations where AS Paths need to be cleanedor manipulated with something more flexible than a straight pre-pend. IOS allows every other key BGP metric to be tweaked and we accept the risks that brings - so this sort of manipulation of the AS-Path is long overdue. Examples where I have had to dump BGP routes into an IGP for a hop and stick them back into BGP with a clean AS-Path. :- A) 2 independant organisations both use MPLS VPN from the same provider and want to exchange routes across a private peering. The MPLS provider AS is in the AS-Path on both sides and the provider drops routes. The provider doesn't offer any of the provider side workarounds. B) 1 Organisation that has historically been a fully private network and has some historic peerings that use non-private AS/non-registered AS now wants to have a private peering with a proper public network. The AS-Path needs to have the junk removed before the routes could be advertised. Yes the historic networks should be migrated away but the fact is there is often no resource and no money to do that when the workaround is simply another Router. C) Organisation wants to Dual Home to 2 ISPs at 2 locations for a new internet service. It wants to use its private network for backhaul between the sites but can't have free flow of routes between because if they traverse the MPLS VPN they get the provider AS inserted in the path. I don't intend to debate the abovethey happened and the solutions were ratified by Cisco but in all cases manipulating the AS-Path (usually to remove the MPLS provider public AS) would have been much much easier than the final solutions. The summary is...BGP isn't just used on the Internet, and corporate networks get messy when CEOs get ambitious (or fired). Dean -Original Message- From: cisco-nsp-boun...@puck.nether.net [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of mas...@nexlinx.net.pk Sent: 28 May 2009 17:56 To: Varaillon Jean Christophe Cc: cisco-nsp@puck.nether.net Subject: Re: [c-nsp] Remove BGP AS path number number from an AS PATH yup, you can't remove public AS from AS path. would you please share the idea why you wana remove it :) there are many other attributes to tweak bgp, y not u use them. BR\\ Masood I doubt that you can do that... but if this is to influence your outgoing traffic, then I would use local-preferences. Christophe -Original Message- From: cisco-nsp-boun...@puck.nether.net [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Michalis Palis Sent: Thursday, May 28, 2009 9:49 AM To: cisco-nsp@puck.nether.net Subject: [c-nsp] Remove BGP AS path number number from an AS PATH Hello All Is their a way to remove the first AS number (not private) from an AS path? For example we are receiving a route with AS PATH 123 456 456 456 and we want to remove the 123 AS and put in the BGP table the route with AS 456 456 456 . Thanks for your reply ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com __ Information from ESET Smart Security, version of virus signature database 4112 (20090528) __ The message was checked by ESET Smart Security. http://www.eset.com ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
