Subject: Re: Any TCP gurus in the house? (RFC1323 and stalling TCP)
To: David Brownlee <>
From: Kevin Lahey <>
List: tech-net
Date: 01/05/2000 18:05:50
In message <>,
David Brownlee writes:
>Subject: kern/9085: enabling RFC1323 support causes some TCP connections to
>    stall
>System: NetBSD picarefy 1.4 NetBSD 1.4 (GENERIC3X) #186: Sat May 8 11:38:37 PD
>T 1999 root@eighty:/play/gwr/netbsd/build/sun3/GENERIC3X sun3
>System connected via Ethernet to a 386 running Linux which is the PPP
>gateway (over ISDN) to the outside world.
>When RFC1323 support is enabled (by default), TCP connections which
>negotiate use of the IP timestamp option may stall: there is more data
>waiting on the remote host to be sent, and all data received has been ACKed
>correctly, but the data will never be sent unless the local host sends data
>to the remote host.

It looks like the packets are getting ACKed by the NetBSD box
correctly, and there is plenty of window.  Some PPP servers out
there will pooch the compression of TCP/IP packets that contain
TCP options;  perhaps that's the problem?  Could you verify the
packets coming in via the Linux box which is doing the PPP?

Or did I miss some subtlety?