nanog mailing list archives
What is multihoming was (design of a real routing v. endpoint id seperation)
From: Michael.Dillon () btradianz com
Date: Mon, 24 Oct 2005 10:01:21 +0100
the market wouldn't feel the need to have to dual home.
the internet model is to expect and route around failure.
Seems to me that there is some confusion over the meaning of "multihoming". We seem to assume that it means BGP multihoming wherein a network is connected to multiple ASes and uses BGP to manage traffic flows. Other people use this term in very different ways. To some people it means using having multiple IP addresses bound to a single network interface. To others it means multiple websites on one server. And to many consumers of network access it is a synonym for redundancy or resiliency or something like that. BGP multihoming is not the only way to satisfy the consumers of network access and design a solution in which failure is expected and it is possible for the customer to route around failure. A single tier-2 ISP who uses BGP multihoming with several tier 1 ISPs can provide "multihoming" to it's customers without BGP. For instance, if this tier-2 has two PoPs in a city and peering links exist at both PoPs and they sell a resilient access service where the customer has two links, one to each PoP, then it is possible to route around many failures. This is probably sufficient for most people and if the tier-2 provider takes this service seriously they can engineer things to make total network collapse exteremely unlikely. Another way in which consumer's could be "multihomed" would be to have their single access link going to an Internet exchange where there is a choice of providers. If one provider's network fails, they could phone up another provider at the exchange and have a cross-connect moved to restore connectivity in an hour or so. This will satisfy many people. Of course there are many variations on the above theme. This is an issue with multiple solutions, some of which will be superior to BGP multihoming. It's not a simple black or white scenario. And being a tier-1 transit-free provider is not all good. It may give some people psychological comfort to think that they are in the number 1 tier, but customers have good reason to see tier-1 transit-free status as a negative. --Michael Dillon
Current thread:
- Re: design of a real routing v. endpoint id seperation, (continued)
- Re: design of a real routing v. endpoint id seperation Owen DeLong (Oct 20)
- Re: design of a real routing v. endpoint id seperation Joe Maimon (Oct 20)
- Re: design of a real routing v. endpoint id seperation Michael . Dillon (Oct 21)
- Message not available
- Re: design of a real routing v. endpoint id seperation Joe Maimon (Oct 21)
- RE: design of a real routing v. endpoint id seperation Neil J. McRae (Oct 21)
- RE: design of a real routing v. endpoint id seperation Randy Bush (Oct 21)
- RE: design of a real routing v. endpoint id seperation Neil J. McRae (Oct 21)
- RE: design of a real routing v. endpoint id seperation Matt Ghali (Oct 21)
- Re: design of a real routing v. endpoint id seperation Tony Li (Oct 21)
- Re: design of a real routing v. endpoint id seperation Randy Bush (Oct 23)
- What is multihoming was (design of a real routing v. endpoint id seperation) Michael . Dillon (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Owen DeLong (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Jeroen Massar (Oct 24)
- Message not available
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Jeroen Massar (Oct 24)
- Re: design of a real routing v. endpoint id seperation Owen DeLong (Oct 20)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) John Reilly (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Owen DeLong (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) william(at)elan.net (Oct 25)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Stephen Sprunk (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Crist Clark (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Valdis . Kletnieks (Oct 24)
- Re: What is multihoming was (design of a real routing v. endpoint id seperation) Owen DeLong (Oct 24)