Subject: RE: Comments on kompella-mpls-l2vpn-02 draft

From: "Li, Eve" <[email-masked]>
Date: Tue, 8 May 2001 09:07:24 -0400

In rfc 2858 [BGP-MP], Page 3: 

      Address Family Identifier:

         This field carries the identity of the Network Layer protocol
         associated with the Network Address that follows. Presently
         defined values for this field are specified in RFC 1700 (see
         the Address Family Numbers section).

on Page 4: 
      Network Address of Next Hop:

         A variable length field that contains the Network Address of
         the next router on the path to the destination system  

My understanding is that these two paragraphs requires Next Hop need to be
of the same format as NLRI for a given address family. But given that a new
address family (l2vpn) is defined, specifying the next hop for l2vpn is
always an IPV4 address is fine with me. 

-eve

-----Original Message-----
From: Quaizar Vohra [mailto:[email-masked]]
Sent: Monday, May 07, 2001 8:35 PM
To: Li, Eve
Cc: [email-masked]
Subject: Comments on kompella-mpls-l2vpn-02 draft

 > BGP's next hop field for L2VPN signalling is not clearly specified. 
 > 
 > Since [BGP-MP] (rfc 2858) requires that the next hop address be in the
same
 > address family as the NLRI.  What the next hop address should be for
 > L2VPN-specific NLRIs?  Thx, 

I couldn't find any such requirement in the rfc. 

Since you want MPLS LSPs terminating in these next-hop addresses, and
currently most implementation use IPv4 addresses as destinations in
the LSPs, it seems like IPv4 addresses are a good candidate for the
nexthop field. 

We will update the L2VPN specification to reflect this as a
recommendation.

Thanks,
Quaizar

 > -eve