If the downstream customers are not multihomed, there's no reason to run BGP with them; a simple default/static will work just fine. Also, if you suballocate addresses to them from within your address space, you can aggregate them. This is generally considered a Good Thing. - paul At 08:06 AM 2/25/97 -0500, Avi Freedman wrote:
I think the general feeling is that if the customer is multi-homed, there's going to be another route announcement for them anyway - whether it's a /23, /24, or /16 or /17.
If the customer isn't multi-homed, and you're their only path, then:
a) If you BGP with them and pass it on to the global 'net, that path will flap if the line goes up or down. This is considered bad.
b) There's no point, if that route is out of your address space, in announcing the more specific if there's no extra path to them if their connection to you goes down.