[c-nsp] RES: conditional bgp default-originate

[Jon Lewis]

On Thu, 14 Aug 2008, Hank Nussbacher wrote:

> On Thu, 14 Aug 2008, Jon Lewis wrote:
>
>> That's basically what I ended up with yesterday in the simulator.  My 
>> problem with it is, without inside knowledge of my upstream networks, how 
>> do I know which routes will never go away or never even just change mask?
>> To be safer, if I end up doing this, I'll probably put half a dozen or so 
>> networks from each upstream in the access-list.
>
> I suggest tracking one block and not a few.  Finding the right one takes 
> about 30 minutes of traceroutes from various LGs.

Since the access-list only needs to match any single listed route to work, 
why wouldn't you track several routes to be safer?

You can look at a few looking glasses and know that ProviderX will always 
announce some CIDR with the same netmask?  That sounds like a neat trick.
Nobody ever deaggregates, right? :)

----------------------------------------------------------------------
  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
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