Re: Fwd: Problem accessing a Certain Remote IP with Kernel 2.6.24-rc1

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Sat, 3 Nov 2007 15:34:18 -0500
Sparkletone <sparkletone@gmail.com> wrote:

> Forwarding this for someone who was getting bounces for some reason.
> 
> Begin forwarded message:
> 
> > From: Shlomi Fish <shlomif@iglu.org.il>
> > Date: November 3, 2007 3:31:56 PM CDT
> > To: sparkletone@gmail.com
> > Subject: Problem accessing a Certain Remote IP with Kernel 2.6.24-rc1
> >
> > Hi all!
> >
> > I hope this mail gets through because last time I checked, I got  
> > bounces
> > whenever I tried to send email to LKML ("not liked source" for mail).
> >
> > I've been having a problem with kernel 2.6.24-rc1 on Mandriva  
> > Cooker. The
> > problem is that after using it for a while connecting through TCP to  
> > the
> > following remote, Internet IP - 212.143.218.31 - takes a very long  
> > time.
> >
> > Here's what I've learned:
> >
> > 1. Kernel 2.6.23 seem to exhibit this problem tooa fter a while.
> >
> > 2. It already happened twice with kernel 2.6.24-rc1.
> >
> > 3. A different computer on the same Home LAN connected via a NAT/ 
> > router has no
> > problem with that IP. (At the same time, the Linux computer exhibits  
> > the
> > problematic behaviour).
> >
> > 4. I could connect using telnet to port 80 eventually, but it took  
> > an awfully
> > long time.
> >
> > 5. I have problem with both HTTP to port 80 and POP.
> >
> > 6. Restarting the network ("/etc/init.d/network restart") does not  
> > help - only
> > a reboot.
> >
> > 7. The network as a whole (Google, etc.) works fine.
> >
> > I need this IP, because it hosts my POP account and my homepage.
> >
> > Per Rik van Riel's advice I prepared Ethereal (libpcap) dumps of the
> > conversations before ("good") and after ("bad") the problem surfaced:
> >
> > http://freehackers.org/~shlomif/files/files/www.sf.org-conn-problem/
> >
> > I'd appreciate if anyone would be able to shed more light on this  
> > problem and
> > hopefully fix it. Please let me know if there's anything else you  
> > need.

Sounds like another instance of the default window scaling causing problems.
Look up TCP window scaling on lwn.net.  There is almost some
stupid middlebox/firewall that doesn't handle window scaling properly.


-- 
Stephen Hemminger <shemminger@linux-foundation.org>