RIR filtering & Level3

Justin Shore justin at justinshore.com
Thu Nov 15 16:13:38 UTC 2007

Just to followup with the list, there was a small omission in the 
filtering of the routes on our peering session.  That accounts for the 
more specific routes we were seeing.  L3 made the filtering change on 
their side and we're back down to within a percent or less of our other 
BGP peers.  It wasn't hurting us; our hardware isn't up against any 
resource limits; I just happened to notice it and thought I'd take the 
opportunity to inquire about RIR filtering with the group.  Thanks for 
the quick work on this one, Roy and Kevin.

I am still interested in implementing some minimum allocation filtering 
on our borders.  I can't think of any reason to accept anything below 
the minimum of a /24.  Can anyone else?  None of the DNS root servers 
are on anything smaller than a /24 are they?  Does anyone have any 
suggestions for implementing this in a sane manner?  I'm assuming 
matching ge 24 would be sufficient unless there are some 
exceptions like perhaps the root servers.


Justin Shore wrote:
> Are any other L3 customers seeing the large number of /25 and smaller 
> routes from L3?

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