BGP Filtering

Jon Lewis jlewis at lewis.org
Sat Jan 19 17:52:03 UTC 2008


On Sat, 19 Jan 2008, Andy Davidson wrote:

> On 15 Jan 2008, at 16:11, Ben Butler wrote:
>
>> As a transit consumer - why would I want to carry all this cr*p in my
>> routing table, I would still be getting a BGP route to the larger prefix
>> anyway - let my transit feeds sort out which route they use & traffic
>> engineering.
>
> Maybe you don't get covering aggregates.  That causes holes.  Whether you 
> care is a matter of local policy, though. :-)

There's no maybe about it.  Filtering on RIR minimums will result in the 
more clue deprived networks disappearing from your view and a loss of 
reachability unless you have default pointed at some network not using 
such a filter.

Since I've gotten several requests recently for the "latest version" of 
what I posted back in September (I guess others are starting to get 
worried/close to their limits), I decided this was a good time to setup 
some blog software (late last night)...and I posted the filter and a brief 
intro to http://jonsblog.lewis.org/

----------------------------------------------------------------------
  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________



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