Subject: RE: PANA FAQ

From: <[email-masked]>
Date: Fri, 24 May 2002 10:40:29 -0500

>> I tend to agree. But the thinking has been that the host could possibly ICMP
>> with IP address 0 to carry EAP payload. So it is possible that we
>> could do authentication without the host having been assigned
>> an address. 
>
>I think this misses a basic point. If a server has to support multiple
>concurrent operations with clients -- with each client using the all
>0's address -- the server needs some other way to distinguish
>connections than IP addresses/port numbers. This would likely be
>something based on the link-layer addresses used. But now, we no
>longer have vanilla IP. We have IP plus the link-layer address. Note
>this is an issue for all higher-layer "connection-oriented" protocols
>(EAP would be one, in the sense that a connection consists of a
>sequence of related packets belonging to a single EAP transaction). So
>it does create complexity and would seem to lose a number of the
>advantages of the pure L3 solution (which I thought was supposed to be
>L2-agnostic).

If we believe there is added complexity that is not worth dealing
within developing a solution for PANA with the all 0's address, then
we could specify a requirement that "PANA MUST not use the all 0's IP
address to communicate with the athentication agent in the network."
This would ensure that the scope is well constrained.

However this would seriously limit the scope of PANA in v4 networks at
least. PANA can use the stateless address autoconfig mechanism in v6
and use that address for the PANA messages. But in the case of v4,
such a reqiurement would imply that we use mechanisms such as PPP (or
DHCP) to obtain an IP address, and if that is the case, then the need
for PANA is quite limited. 

Maybe we should look at other alternatives such as having a temporary
IP address (from a reserved pool) assigned to the host specifically
for the task of PANA signaling, and if successful, can be substituted
with another adress for the host to use (security implications need
to be studied).

>Thomas

-Basavaraj