09-16-2010 01:05 AM - edited 03-04-2019 09:47 AM
Dear all,
Though its unsafe to start tampering with AS path, I am in a situation where I need to get rid of a private AS that is appended right behind a public AS.
IOS see this as a config error and remove-private-as becomes obsolete ( junos does not).
I came across few posts with the command "set as-path exclude" but cannot seem to find any more info about it on Cisco.com.
Any thoughts or pointers ?
TIA
Sam
09-16-2010 03:35 AM
Hi,
AFAIK, once you are receiving a mixture of public and private AS numbers within the AS-PATH, the only way to remove the private one(s) is to remove the AS-PATH completely by redistributing to an IGP and manipulate the AS-PATH when redistributing back from IGP to BGP.
Which is quite complicated and requires multiple routers (or VRFs) involved.
BR,
Milan
09-16-2010 03:52 AM
The command to perform AS_PATH striping is "neighbor
By the way are you using the private AS number? you ISP should remove that when they advertise your prefixes!!
Francisco.
09-16-2010 04:02 AM
@francisco_1:
neighbor
BR,
Milan
09-22-2010 05:42 AM
Thank you both for the replies !
I considered BGP>IGP>BGP redistribution which a workaround...but opted for a cleaner design which was to simply redesign my set up and avoid a mix of Private and public ASs.
Thanks
Sam
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