Re: Non-ISP companies multi-homing?

[root () gannett com]

> Without the ISP having total control over the customer  
> router, a misconfiguration of filters on the customer side  
> could easily cause the customer to be a valid (and 1 hop)  
> path in the tables from ISP A to ISP B. Doesn't sound  
> like a possibility I would be willing to have hanging over  
> my head.

Well, since my bandwidth is necessary for my business, I think I'd be 
much more concerned about becomming the valid route than my upstreams, if 
they get better routing through me, it's not necessarily a bad thing 
for them unless they're concerned about me snarfing traffic.  

Plus, you can filter out what you send to me if you're my upstream.  That 
means you'll need a misconfigured router on your side *and* one on mine.  
I don't know your competency, but I'm fairly certain of mine ;).  I put a 
lot more time, effort and care into choosing a provider than you do into 
choosing a customer.   

I don't think it's as big of an issue, other than the obvious 
effects of router filtering performance, and the chance that the upstream 
could hose his filters when he goes to listen for routes to me from 
external sources if he's already got major paranoia filters.  Hopefully, 
he's got that filtered to only happen from my other peering points though.

It's not rocket science, but it does take some care in set-up.  You have 
as much chance of getting control of my gateway routers as you have of 
turning into a purple poodle.  I'd purchase Yet Another Service Provider 
and route a tier lower before I'd play that game.  I've got a lot more to 
lose than my upstreams.

Paul
-------------------------------------------------------------------------
Paul D. Robertson
gatekeeper () gannett com