The IP Over NBMA (ION) Archive

[gardo@VNET.IBM.COM]

> I was wondering if any work has been done on extending NHRP beyond
> NBMA networks, to provide a cut-through path over ELANs, for example.
> Any thoughts on the advantages/disadvantages of this?

Yes!  Here is what I have done and how NHRP can be used:

MAC addresses are put into the NBMA address fields of NHRP packets, and
the "LAN 802" address family type defined in RFC-1700 is used in the
NHRP fixed header (ar$afn = 6).  It's simply NHRP frames over an ELAN.
If the NHS finds the destination attached to a like ELAN, it performs
ARP to obtain the MAC of the destination and sends this MAC address
in an NHRP Resolution Reply to the NHRP client.  I'll call the MAC
address that is retrieved via NHRP the "shortcut MAC".

This could enable one to do neat things like:

  -- This shortcut MAC could be registered with the LAN
     Emulation Server using LANE's "LE Registration Protocol".
  -- Send 2 sets of address family information in the reply, one
     for the shortcut MAC and another to identify the LEC that
     "owns" shortcut MAC.
  -- Send unicast traffic directly to a LEC, by appearing as a LEC....
  -- etc...

Is there any interest in making any of these capabilities part of the
NHRP draft ?  This would make NHRP even more flexible, by making the
NBMA address more general and more in-line with the definition of the
"address family" in RFC-1700.  In fact, the addresses carried in NHRP
messages could be any valid "address family" defined in RFC-1700.  If
this is going too far, then, let's at least include MAC addresses.

>
> -Fran
>
> -------------------------------------------------
> Fran Reichmeyer            phone: 508.266.2312
> Ascom Nexion               fax:   508.266.2300
> 289 Great Road             email: fran@nexen.com
> Acton MA, 01450
> -------------------------------------------------
> =========================================================================
> Date: Thu, 06 Jun 1996 12:46:42 -0400
> To: Fran Reichmeyer <fran@nexen.com>
> From: Paul Ferguson <pferguso@cisco.com>
> Subject: Re: NHRP beyond NHRP
> Cc: ion@nexen.com
> Sender: owner-ion@nexen.com
>
> This is what I had hinted at last week in mentioning methods to use
> NHRP to define tunnel end-points.
>
> - paul
>

-- Russell