Subject: Re: small bug in BSD timestamp code

From: Thomas Skibo <[email-masked]>
Date: Mon, 13 Sep 1999 13:25:23 -0700

> Or, there is a bug in the other guy's stack...  

A bug could corrupt the echo-reply in a lot of ways (2^32-1 different
ways :-) ), all of which would screw up RTT measurements.

-- 
Thomas Skibo		Juniper Networks, Inc.		[email-masked]

---

From: Mark Allman <[email-masked]>
Date: Mon, 13 Sep 1999 16:20:25 -0400

> Ideally, the ECR should be ignored if it's zero because that's what the
> other guy uses if he doesn't have a valid TS.recent (for a SYN or if
> the "24 day connection" timeout occurred).  But, in all cases where
> you're going to use an ACK to update the RTT (the ACK acks new data),
> the peer ought to have a valid TS.recent from the segment for which
> you're trying to get acknowledgement.
> 
> ...unless there's some other way that TS.recent is discarded that I
> can't remember.

It still seems like a good sanity check to me.

allman