Subject: Verification Tag in SHUTDOWN-ACK

From: Vladislav Yasevich <[email-masked]>
Date: Fri, 20 Feb 2004 15:36:20 -0500

Hi

Another question that has probably been answered before...

How come the Verification Tag is not checked when receiving
a SHUTDOWN ACK chunk?

This is all I could find in 9260:

  E) Rules for packet carrying a SHUTDOWN ACK

       -  If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
          procedures in section 8.4 SHOULD be followed, in other words it
          should be treated as an Out Of The Blue packet.

It seems like there is a potential for an untimely closure of
an association if a spoofed shutdown-ack is processed.

Thanks
-vlad
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Vladislav Yasevich		Linux and Open Source Lab
Hewlett Packard 		Tel: (603) 884-1079
Nashua, NH 03062		ZKO3-3/T07

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From: "Brian F. G. Bidulock" <[email-masked]>
Date: Fri, 20 Feb 2004 13:57:24 -0700

Vladislav,

All packets must pass verification tag checks.

--brian

-- 
Brian F. G. Bidulock    ¦ The reasonable man adapts himself to the ¦
[email-masked]    ¦ world; the unreasonable one persists in  ¦
http://www.openss7.org/ ¦ trying  to adapt the  world  to himself. ¦
                        ¦ Therefore  all  progress  depends on the ¦
                        ¦ unreasonable man. -- George Bernard Shaw ¦