Subject: Re: GSMP Adjacency Protocol

From: Peter Newman <[email-masked]>
Date: Tue, 05 Jun 2001 10:07:23 -0700

Another question:

 >It seems clear from the state tables that an entity which *sends*
 >a RSTACK doesn't perform a "reset the link" operation. Am I correct
 >in thinking that this (sending) entity will update its instance
 >and delete the peer verifier as a result of the response of the
 >remote entity to the RSTACK message? Is there some intuition behind
 >this? It seems to me more intuitive that when an entity tells a
 >remote entity to reset the link state, it will reset its own link
 >state as well.

you want to reset each direction independently.

in particular, the system generating an RSTACK doesn't know that the packet
which caused it to send the RSTACK isn't an "old" packet, so it just "turns
around" the incoming packet, changes the code to RSTACK, and sends it to its
peer (not changing *its* state at all).  the system receiving an RSTACK *does*
have enough information to decide if the RSTACK was generated by an old packet
(in which case it ignores the incoming RSTACK) or a by new packet (in which
case it resets its link state).

i believe TCP RST works this same way; i probably just copied the idea from
there.

cheers,  Greg Minshall