On Thu, 30 Jun 2005, Scot Jenkins wrote:
> I have several systems that I recently upgraded from Debian woody to 
> sarge.  On systems where I've upgraded the kernel, I have a strange 
> networking issue.  I do secondary MX for a friend (we'll call his host 
> friendmail) and after the OS upgrades on my end, I started spooling mail 
> for him.  I contacted him thinking his mail server was down but it 
> turned out that from my Debian mail server, I couldn't telnet to 
> friendmail:25.  I could not telnet to any other open ports on his IP, 
> 80, 22, etc.  I was able to telnet to other random hosts on various 
> ports just fine.

Do you have ECN enabled?

cat /proc/sys/net/ipv4/tcp_ecn

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| nate carlson | natecars at natecarlson.com | http://www.natecarlson.com |
|       depriving some poor village of its idiot since 1981            |
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