From mboxrd@z Thu Jan  1 00:00:00 1970
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
In-reply-to: Your message of "Thu, 17 Apr 2008 09:18:31 BST."
	<788e22747d8aa85911d08c6c0d9804c7@terzarima.net>
From: Bakul Shah <bakul+plan9@bitblocks.com>
Date: Thu, 17 Apr 2008 11:41:51 -0700
Message-Id: <20080417184152.369735B52@mail.bitblocks.com>
Subject: Re: [9fans] telnet vs. godaddy whois
Topicbox-Message-UUID: 90e36e46-ead3-11e9-9d60-3106f5b1d025

On Thu, 17 Apr 2008 09:18:31 BST Charles Forsyth <forsyth@terzarima.net>  wrote:
> > having said that, i now suspect that sending one byte into a zero-window is
>  not the problem.
>
> because the one-byte probe can only be done if there is data to send, and i
> already knew that a plain connection (dial only) to that port also failed:

Not setting the PSH bit on a pure ACK (== no data is being
sent) seems to fix this (see ip/tcp.c around line 2530).  May
be it tickles a bug on the receiver (0 byte read?).