A long HBH Options question

[Ron Bonica <[e-mail]>]

Folks,

According to RFC 8200:

  "The Option Type identifiers are internally encoded such that their
   highest-order 2 bits specify the action that must be taken if the
   processing IPv6 node does not recognize the Option Type:

      00 - skip over this option and continue processing the header.

      01 - discard the packet.

      10 - discard the packet and, regardless of whether or not the
           packet's Destination Address was a multicast address, send an
           ICMP Parameter Problem, Code 2, message to the packet's
           Source Address, pointing to the unrecognized Option Type.

      11 - discard the packet and, only if the packet's Destination
           Address was not a multicast address, send an ICMP Parameter
           Problem, Code 2, message to the packet's Source Address,
           pointing to the unrecognized Option Type."

Also according to RFC 8200:

"While [RFC2460] required that all nodes must examine and
   process the Hop-by-Hop Options header, it is now expected that nodes
   along a packet's delivery path only examine and process the
   Hop-by-Hop Options header if explicitly configured to do so."

So, let's assume that:

- A packet contains an HBH option and the high-order bits of the HBH Option type are "10".
- The packet traverses Router A and Router B on route to its destination
- Router A is not configured to process HBH options
- Router B is configured to process HBH options
- Neither Router A nor Router B recognize the HBH option contained by the above-mentioned packet.

I think that RFC 8200 requires the following behavior:

- Router A forwards the packet to Router B, without examining the HBH Options header
- Router B discards the packet, because it doesn't recognize the option.

Is this the required behavior? If so, does this behavior cause cognitive dissonance for anybody else?

I am thinking that the "act" bits are meaningless in the HBH extension header. This discussion may also be applicable to draft-herbert-ipv6-update-dest-ops.

                                                                   Ron