Re: Transport level multihoming

[Greg Maxwell <gmaxwell@martin.fl.us>]

On Wed, 8 Aug 2001, Brian E Carpenter wrote:

> Yes, this is one way to do it (almost identical to the "bump in the API"
> approach to v4/v6 interworking). I don't see any reason why the IP address
> returned by the resolver needs to be bogus; surely it can simply be any one
> of the real IP addresses, which might have some advantages.

My only reasoning for not using one of the actual IP addresses is that
some hosts may advertise a different set of addresses based on application:

Consider a single host with two DNS names:

ftp.host.company.com = A,B,C,D (where the letters are addresses in
				different prefixes)
www.host.company.com = A,B

Why? C,D are high latency satellite links.

The host is smart enough to not include the high-latency links in any
assotiation binding in it's transport protocol for port 80. However, we
don't want remote systems to attempt to initiate across those slow links
either.

Of course, we could just declare that those kinds of smarts belong to
applications that are aware of the transport-level multihoming (in that
they pass all the addresses themselves) and go ahead and use one of it's
correct IP addresses.

This was my reasoning for using bogus identifyers.