If you accept a default route only from each provider, this would gives you some load sharing and redundancy but your chances of suboptimal routing are fairly high. Accepting more routes from the providers raises the chances of more optimal routing because you have more information to work with.
Your options are primarily limited by your router platform. If you wanted to accept default only and had two T-1s you could probably get away with a 2501. I wouldn't try it, but it might work. You could certainly do it with a 2620. With BGP and lots of routes, you need speed and memory. The 2650 adds more speed and -- I think -- 128MB of DRAM. You might be able to squeeze in full routes from two providers on that machine but I wouldn't try it. However, you could easily accept customer-only routes with no problem. At the present time, we're accepting customer-only routes from two different big providers and if I remember correctly we've got about 50,000-60,000 routes in the BGP table. We're doing this on a 3640 with 128MB of DRAM and we're using around 60MB. As far as processor goes, it hardly knows it's turned on. To summarize, if you've got the memory and the horsepower, you might as well accept full routes. If not, be careful because you don't want to overload your link or your router. If you accept default-only, then you configure some form of route cacheing on your router and it will do per-destination load sharing across the two links. HTH, John >>> "brian kastor" 3/12/02 7:15:05 AM >>> I have looked at http://www.cisco.com/warp/public/459/40.html and I understand multihoming to 2 different providers. What I can't seem to figure out is if I need a full routing table on the router to make this work. Can someone explain why, if I have 1 router, 2 isp's, multihomeing, how I can use default routes from bgp.... or at this point do I need a full routing table? thanks, ipguru Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37955&t=37948 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
