Subject: RE: Question on initial sequence numbers

From: Sankar Ramamoorthi <[email-masked]>
Date: Mon, 4 Jan 1999 16:46:37 -0800

The problem becomes more significant with devices like network appliances,
becoming more common. These have characterstics like High Availability, fast
reboot
times etc. It is likely all TIME-WAIT is lost across reboots/failover.

-- sankar --

-----Original Message-----
From: Kacheong Poon [mailto:[email-masked]]
Sent: Monday, January 04, 1999 3:42 PM
To: Vernon Schryver
Cc: [email-masked]; [email-masked]
Subject: Re: Question on initial sequence numbers

> In both problems, isn't the worst case a TIME-WAIT delay, and not the data
> corruption of the likely implementation of the alledged random Microsoft
> ISS's?   Of course, over the years we've each heard vastly more complaints
> about TIME-WAIT delays than about data corruption, and never mind
validity.

I guess the reason is that most implementations' ISN go forward instead of
backward a little bit as described in the original mail about MS stack.
Going
forward a little bit in sequence number space is better in protecting
against
sequence number collision than going backward a little bit, which is
equivalent to going forward too much.

							K. Poon.
							[email-masked]

---

From: Joe Touch <[email-masked]>
Date: Tue, 05 Jan 1999 16:33:41 -0800

> times etc. It is likely all TIME-WAIT is lost across reboots/failover.

The 2*MSL is supposed to be ensured; this is accomplished by either:

	- a reboot that takes 2*MSL anyway

	- prohibiting new connections for 2*MSL after a reboot

Accepting new connections immediately after a quick reboot
would be 'breaking' that rule.

Joe

---

From: "Eric A. Hall" <[email-masked]>
Date: Tue, 05 Jan 1999 10:44:16 -0800

> would be 'breaking' that rule.

Almost every OS that I've ever tested breaks this rule, unfortunately.

-- 
Eric A. Hall                                            [email-masked]
+1-650-685-0557                                    http://www.ehsco.com