Subject: RE: [Ipoverib] DHCP over InfiniBand

From: "Larsen, Roy K" <[email-masked]>
Date: Tue, 26 Mar 2002 17:03:34 -0800

Vivek,

This looks good.  Thanks.  I do have one question.  I assume that the
"invariantness" of the interface-id would also apply to the chaddr if that
were available to us.  Does this mean that if the IPoIB hardware address
were <= 16 bytes and contained the QPN that it would still be unusable for
DHCP?  What I'm trying to get at is, why can't we just say the
client-identifier IS the IPoIB hardware address found in an ARP?  Is the
"variantness" of the hardware address acceptable in ARP but not in DHCP?
The asymmetry concerns me and I just want to make sure there are no
stumbling blocks down the road related to the variant nature of the IPoIB
hardware address.

Roy

-----Original Message-----
From: Vivek Kashyap [mailto:[email-masked]]
Sent: Tuesday, March 26, 2002 3:38 PM
To: [email-masked]
Subject: [Ipoverib] DHCP over InfiniBand

I submitted the following draft based on the discussions we had on the
mailing list and at the IETF meeting. It doesn't appear to me that we
are moving in the direction of shortening the link-layer address. So
the 'broadcast bit' is the solution.

Please comment.

Thanks
	Vivek

<snip>

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---

From: Vivek Kashyap <[email-masked]>
Date: Tue, 26 Mar 2002 18:05:05 -0800 (PST)

Roy,
        The DHCP server needs a value by which it can uniquely
        identify the client. This uniqueness is certainly satisfied by
        the use of the IPoIB link address. 
	
        The server records this unique identifier in its database. But
        for the server to be able to utilise this information across
        client boots the client must present the same identifier to
        it; hence the suggestion of invariance of the
        client-identifier. 

        If the chaddr field is used and the client-identifier is not
        used, then too the same 'chaddr' field must be presented to
        the server to ensure the server can recognise the client.

        Note that this issue is of prominence here only because there
        maybe multiple IPoIB interfaces associated with the same GID.
        An EUI-64 value or the GID will do otherwise. If you plan to
        use only one IPoIB interface per GID then there is really no
        issue - just use the GID.

        If the IPoIB link address was equal or less than 16-bytes then
        we wouldn't have to use the Broadcast bit. 

Vivek

-- 
Vivek Kashyap
Linux Technology Center, IBM
[email-masked] 
[email-masked] 
503 578 3422 (o)