On Fri, Aug 24, 2001 at 06:04:19AM -0400, Daniel Golding wrote:
Leo is exactly right. The real reasons that folks multihome are:
1) Backbone and/or routing instability striking one upstream provider 2) Local loop/fiber cuts
That's pretty much it.
how about, 3) The desire to have the customers of backbone providers with rather different customer bases be able to efficiently reach a target site? (example: a US provider with lots of business customers, a dial-up/DSL concentrator, and a European provider with lots os EU customers; you might choose to buy transit from all three)
There are many, many more reasons. To begin with: 4) Desire not to be held hostage by your ISP when billing disputes or other problems occur. 5) Desire for additional leverage when negotiating with your ISP, "I can pull my circuit to you right now and my network will not be affected. If you can't match my latest offer from XYZ Corp, I'll just flip the switch." 6) Ability to reduce the average number of hops between your networks and various important other sites. Ability to reduce the points at which outages or packet loss can occur. 7) The comfort of knowing you won't have to worry about the latest crazy idea your ISP dreams up. For example, "Starting thursday, we require all IPs to have valid, matching forward and reverse DNS or we won't route to them". I'm sure people have other examples of similar insanities. 8) No need to worry about what happens if your ISP gets slow or overcommitted. You just shut them off while you find another ISP to replace them. There are more reasons. These are just a small number of them. DS