Subject: Re: [AAA-WG]: Issue 305: Purpose of MIP-Foreign-Agent-Host

From: Sivasundar Ramamurthy <[email-masked]>
Date: Fri, 29 Mar 2002 09:36:44 -0800 (PST)

Hello,

I might have a couple of uses for this avp.

1. The assumption here is that the FA-HA key is not session specific
(see Issue: 317).

When the HAR containing the HA-FA key is received by the HA, the HA
needs to know which FA the FA-HA key is for. The COA in the
reg-request must be one of the FA's addresses but need not be the
address from which the FA forwards UDP reg requests to the HA.  The
FQDN in FA-Host AVP might be a more reliable way to identify the FA
and store the key against.

When a UDP MIP request containing a FA-HA auth ext is received, the HA
can get the host name of the FA from the source address (DNS) and
determine if it has a SA to that FA. Hopefully the address the FA uses
to forward the request matches against the hostname retrived from the
FA-Host AVP in the HAR.  

NOTE: If this usage, and thus the necessity of this AVP, makes sense,
maybe we can extend it as an argument for requiring support for the
GNAIE drafts; the presence of a FA-host NAI in normal (UDP) reg
requests will let the HA find a key for the FA (without using DNS) and
authenticate it.

2. Section 1.3 in the MIP draft has text that says:

"...it is necessary for the resulting HAR received by the HA to be
identified as a continuation of an existing session".

Maybe the FQDN in the FA-Host-AVP is a reliable way to determine
session continuation??

thanks!

Siva