1. BGP UPDATE-v2 Gargi Nalawade Himanshu Shah

2. Problem description Current UPDATE message was intended to carry IPv4 NLRIs Non-IPv4 NLRIs as well as NEXTHOP are carried in MP_REACH and MP_UNREACH attributes. MP_REACH / MP_UNREACH are attributes, but carry NLRIs. In case of attribute length errors, there is no way to figure out which AFI/SAFI the update belongs to. Not good for AFI/SAFI separation, since AFI/SAFI is not known in case of attribute length errors

3. BGP Update – Encodings Unreachables Attributes -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -MP_REACH -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -MP_UNREACH Reachables AFI / SAFI Unreachables Attributes Reachables Current UPDATESuggested UPDATE

4. BGP Update – v2 Encoding +------------------------------------------------------------------------+ | AFI (2 octets) | +------------------------------------------------------------------------+ | SAFI (1 octets) | +------------------------------------------------------------------------+ | Reserved (2 octets) | +------------------------------------------------------------------------+ | Withdrawn Routes Length (2 octets) | +------------------------------------------------------------------------+ | Withdrawn Routes (variable) | +------------------------------------------------------------------------+ | Total Path Attribute Length (2 octets) | +------------------------------------------------------------------------+ | Path Attributes (variable) | +------------------------------------------------------------------------+ | Network Layer Reachability Information (variable) | +------------------------------------------------------------------------+

5. BGP Update – v2 – Spec changes New message type. New capability to support UPDATE-v2 message. MP_REACH and MP_UNREACH attributes are obsoleted in the new UPDATE-v2 message. NEXTHOP attribute will have the encoding as defined in "BGP NEXTHOP-v2“ draft (draft- lefaucheur-bgp-mp-nexthop-01.txt). If peer supports UPDATE-v2, then it shouldn’t accept current UPDATE message (current UPDATE message).

6. BGP UPDATE-v2 All attributes other than NEXTHOP remains same. Doesn’t have ability to carry more than one AFI/SAFI in an update message, but who does that anyway? Can achieve Address-family separation since AFI/SAFI is the first tuple in the UPDATE message.