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

[Hank Nussbacher]

On Thu, 14 Aug 2008, Jon Lewis wrote:

>> if it does, that means their backbone has gone down.  Do a few 
> traceroutes 
>> and you will quickly figure out what are their backbone CIDRs to use.
>
> 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.

-Hank