Re: [Bier] Questions regarding <draft-zhang-bier-bierin6-03>

[Antoni Przygienda <[e-mail]>]

2.1.  IPv6 Options Considerations



   RFC 8200 section 4, defines the IPv6 extension headers.  Currently

   there are two defined extension headers, Hop-by-Hop and Destination

   options header, which can carry a variable number of options.  These

   extension headers are inserted by the source node.



   For directly connected BIER routers, IPv6 Hop-by-Hop or Destination

   options are irrelevant and SHOULD NOT be inserted by BFIR on the

   BIERin6 packet.  In this case IPv6 header, Next Header field should

   be set to TBD.  Any IPv6 packet arriving on BFRs and BFERs, with

   multiple extension header where the last extension header has a Next

   Header field set to TBD, SHOULD be discard and the node should

   transmit an ICMP Parameter Problem message to the source of the

   packet (BFIR) with an ICMP code value of TBD10 ('invalid options for

   BIERin6').

[XJR Q6]: You have to walk the ext header chain and get the last NH to judge if this packet need to be discard, right? For example for an incoming packet(ipv6hdr+RoutingHeader+DestOptHdr<nh!=TBD>), you have to walk the whole extension header chain until you know the last NH, to execute the above “discard” action. Right?




prz> topic for discussion. The whole v6 options consideration is basically a first stab.


   This also indicates that for disjoint BIER routers using IPv6

   encapsulation, there SHOULD NOT be any IPv6 Hop-by-Hop or Destination

   options be present in a BIERin6 packet.

[XJR Q7]: What does “disjoint BIER router” mean?


prz> non-adjacent, good catch