David, I think what Avi meant was that if you take full routing table and not using default, chances are that no matter how many backup providers you have, you are still risking dropping packets on *YOUR* router if routes to a particular location are lost. This makes you look bad when your customer traceroutes. If you have default then even if all the external routes get lost you can still deliver the packets to your provider and let him drop it. This looks favorable from your customer's traceroutes. In practice, it is better to drop it as early as possible because any additional delivery is unnecessary, but... Jun -- o o o o o o . . . ___========_T__ ___========================_T__ o _____ || Jun J Wu | | jun@wolfox.gsl.net | .][__n_n_|DD[ ====____ | Global One | | http://wolfox.gsl.net/jun | |
(________|__|_[________]_|_____________|__|____________________________|_| __/oo OOOOO oo` ooo ooo 'o^o o^o` 'o^o o^o`
===== David ``Joel Katz'' Schwartz previously wrote: ====
On Mon, 8 Apr 1996, Avi Freedman wrote:
Now, many 2nd level providers that *could* operate default-free choose not to. Even if you have three or more sets of 30k+ routes each, it takes balls to risk dropping packets that your customers want you to deliver just so that you can have the packet be dropped at your router instead of at your (possibly backup) transit provider's router.
Avi
Can't anyone who takes full routes from any tier 1 provider operate without a default route? And isn't it a reasonable assumption that if you don't have a route somewhere, odds are they don't have a route to you (assuming you do your own BGP routing) and so a default route is mostly pointless anyway?
What am I missing?