Here is a good reference/place to start:

- paul

Thanks for the reference, Paul.

I should have put a pointer at that location to the newer one: - a rewritten one with
more details...


Avi <who only reads NANOG every week or so at current volume>

Apropos of the multihoming discussions here in general, I've posted an I-D
intended to help clarify some confusing alternatives. Discussions on NANOG,
as well as my student questions, suggested to me there might be a need for
a tutorial at a different level of abstraction than the specific technique
discussions that are available.

It's not intended to show how, for example, to do BGP multihoming. It's
intended to help someone, especially an end user organization, decide what
the problem is they are trying to solve. Once they know that, the next
step will be selecting DNS-based methods, and/or routing-based methods
using BGP or IGPs. Comments very welcome, especially in the DNS area.

My plan is to submit this to the IDR WG at the IETF in December, but it's
an individual contribution at this point.

                  To Be Multihomed: Requirements & Definitions

2. Abstract

As organizations find their Internet connectivity increasingly critical
to their mission, they seek ways of making that connectivity more
robust. The term ''multi-homing'' often is used to describe means of
fault-tolerant connection. Unfortunately, this term covers a variety of
mechanisms, including naming/directory services, routing, and physical
connectivity. This memorandum presents a systematic way to define the
requirement for resilience, and a taxonomy for describing mechanisms to
achieve it. Multiple mechanisms may be appropriate for specific
situations, including DNS, BGP, etc.