RE: draft-gundavelli-v6ops-l2-unicast WGLC

["Hemant Singh (shemant)" <[e-mail]>]

Brian,

-----Original Message-----
From: Brian Haberman [mailto:[e-mail]] 
Sent: Tuesday, August 17, 2010 12:03 PM
To: Hemant Singh (shemant)
Cc: Ole Troan; Sri Gundavelli (sgundave); Suresh Krishnan; IPv6 WG
Mailing List
Subject: Re: draft-gundavelli-v6ops-l2-unicast WGLC

>Now, what I see you arguing above is that the router will receive this
>message, but may try and pass it to a *different* ULP.  I think we
agree
>that the router will receive the packet since it is addressed to one of
>its L2 addresses.  

Yes, agreed.

>Now, when it is parsing this message I don't see how
>the L2 destination address will have any impact on which protocol this
>message is handed to.  All the routing platforms I am familiar with
>follow a coarse (and high-level) logic like:

>1. Verify L2 validity (e.g., checksum)
>2. Pass packet to protocol handler based on e.g., ethertype
>3. For IPv6, parse Next Header field
>4. Process MLDv2 Report

>So, I can't see a scenario where the L2 destination address interferes
>with the proper handling of the L3 information.

I agree that routers platforms have logic as your describe above.
However, there is no reason why some platform cannot have dedicated
logic from L2 multicast sniffer to a multicast-only ULP and likewise
from the L2 unicast code go to a unicast-only ULP.  Such platforms are
not the norm, so I will go with your logic above and rest my case.

Thanks,

Hemant