nanog mailing list archives

Re: honoring AS-path prepend from a peer or customer?


From: Danny McPherson <danny () qwest net>
Date: Mon, 22 Feb 1999 00:19:36 -0700

Perhaps you should reread the original message regarding issues
associated with honoring undocumented/misrepresented AS Paths..  

As for what you mention below, perhaps you should have a look at the 
document referenced in the latter portion of my original message.  I 
can say from several years of Operational experience, what you suggest 
below, in the context it's in, isn't a very good idea.  There are 
much more intelligent mechanisms to obtain desired ingress and egress
traffic distribution..

Now, perhaps applying policies or the like based on AS_PATH would 
be reasonable to some extent, but suppressing or manipulating specific
path entries is only asking for trouble.  Bedsides that, I'm not aware
of any router vendor shipping code that would do anything along these
lines, with the exception of the "private-AS" stuff that some support..

-danny

Terence wrote:
It's very useful if you want to keep a link rather free of traffic in case
of a backup service from another NSP, and then when your big pipe goes
down, you have this other service with routes intact ready to roll without
intervention. 


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