T3 or not to T3

Avi Freedman freedman at netaxs.com
Mon Jul 22 05:42:01 UTC 1996

> It's pretty easy to enforce "no transit" at the packet filtering level
> -- only packets destined for my nets will be allowed in.  Is there some
> other aspect of filtering I'm forgetting about?  We have a dedicated
> and backup network engineer at any rate.  The border router would be a
> cisco 7200 or 7500 series with 128Mb.
> Dean

Hmm...  If you do provide transit for others, making a dynamic filter
can be difficult if you base transit on as-path filters rather than
route filters.  

I hear that Sprint, one of the few large providers (that imposes filters
on customer BGP sessions) that still bases customer peering filters on 
as-path filters rather than on a per-session route filter list either 
manually constructed or built automagically from databases, is considering 
going or is going to go to route filtering its customer sessions rather 
than as-path filtering.  Now, I'm talking here about the BGP sessions, 
not the actual flow of data.  And it's been a long weekend, sorry if that
sentence was hard to parse.


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