Re: LIN6 and multihoming (+sec)

["Howard C. Berkowitz" <hcb@clark.net>]

I'd like to use this comment as a springboard to what might be called 
a meta-discussion of multihoming requirments.

At 11:26 AM +0300 8/18/01, Pekka Savola wrote:
>[http://www.ietf.org/internet-drafts/draft-teraoka-ipng-lin6-01.txt]
>
>As LIN6 was presented at multi6, and I don't know of a better place to
>comment on this, I guess I'll just post these here..
>
>The fact is that the multihoming support of LIN6 is only limited to single
>nodes, clearly made cellular mobiles in mind:
>
>[snip]
>
>
>I don't think people generally want to multihome every node, rather
>multihome a router and provide multihomed connection that way.

This is where I partially disagree. Yes, I can understand that it is 
generally not required to multihome cellular mobile hosts.  I hope I 
may be forgiven for loose terminology if I call them "clients."

"Server" hosts, in contrast, very reasonably will be multihomed to 
routers. Indeed, there may be complex relationships of multiple 
servers and multiple routers.

The mechanism of server to router multihoming will vary with the 
application. When the multiple routers are on the same subnet as the 
server, a mechanism as simple as VRRP may suffice, perhaps with 
multiple VRRP groups for a degree of load-sharing.  As the servers 
and routers become more distributed, some NAT or transport based 
mechanism may be needed, or the servers may need some awareness of 
routing.

Howard Berkowitz
Nortel Networks