Subject: [Tsvwg] (no subject)

From: "Vijay Kumar Choudhary" <[email-masked]>
Date: Thu, 27 Sep 2001 16:19:56 +0530 (India Standard Time)

Hi all,
   The following line is written in RFC 2960 , page 61,
   
   "If the State Cookie is older than the lifespan carried in the State
Cookie and the Verification Tags contained in the State Cookie do not match
the current association's Verification Tags, the packet,including the COOKIE
ECHO and any DATA chunks, should be  discarded. "
 
In the above sentence i didnt understand the line 
"Verification Tags contained in the State Cookie do not match the current
association's Verification Tags"
 
Which verification tag is it talking of ??? Is there any verification tag
field in the state cookie?? Is it talking of Peer Tie Tag and Local Tie
Tag??
 
Regards,
Vijay

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---

From: [email-masked]
Date: Thu, 27 Sep 2001 14:07:30 +0300

Hi Vijay!

> -----Original Message-----
> From: ext Vijay Kumar Choudhary [mailto:[email-masked]]
> Sent: 27. September 2001 13:50
> To: [email-masked]
> Subject: [Tsvwg] (no subject)
> 
> 
> Hi all,

	Well, when you receive the COOKIE ECHO, in the normal case, you
don't have any other information about the association but the one that is
inside the Cookie... So, as the peer told you its Verification Tag in the
INIT chunk, you have to put that information inside your cookie, otherwise
you don't have any way to know which Verification Tag to use in the
datagrams you send so the peer will accept them.

	Moreover, you suddenly receive a COOKIE ECHO chunk, carried in a
datagram that contains a certain Verification Tag. You can blindly believe
that that VT is the one you included in your INIT ACK (in any case, the
Cookie seems to be valid so...), or you can also save it inside the Cookie,
so once you receive the COOKIE ECHO chunk you can check that the peer used
the right VT...

	So at least you write your VT (the one you use in your outgoing
datagrams) inside the Cookie, the peers one I guess is kind of optional
(anyway, I also include that information in the Cookie) or you can simply
use the VT that comes in the incoming datagram carrying the COOKIE ECHO (I
wouldn't advice you to do this, as somehow you are giving to the peer
freedom to choose both VTs). But these tags are not the Tie Tags, they are
the "normal" tags...

	I hope this helps...

	BR Iván Arias Rodríguez