Hanging Website: TCP Problem?

[Aaron VanDevender]

I was trying to visit the website www.nap.edu (National Academies Press)
using my FC6 desktop machine, but firefox just grinds on it indefinitely
with "Waiting for www.nap.edu...";. I can telnet to port 80 of the site,
and it connects, but after saying "GET /" it just hangs, and never
returns anything.

This would seem like a problem with their site, except that I tried it
with an FC3 machine (kernel-2.6.12-1.1381_FC3) and was able to surf
normally. I also tried telneting to port 80 from the FC3 machine, and
"GET /" immediately returned the correct front page to the site.

I thought that it might be the an ECN problem, but it is set to 0 on my
machines. I've seen the bad behavior on two separate FC6 machines, so I
don't think it's a fluke.

Dose anyone know what might be causing this site to hang with FC6?

-Aaron

[Cameron Simpson]

On 17Jan2007 15:55, Aaron VanDevender <sig(a)netdot.net&gt; wrote:
| [...] I can telnet to port 80 of the site,
| and it connects, but after saying "GET /" it just hangs, and never
| returns anything.

You know you need to say:

  GET / HTTP/1.0

and press [enter] twice? The site may well be broken, but at least test
it with valid HTTP...
-- 
Cameron Simpson <cs(a)zip.com.au&gt; DoD#743
http://www.cskk.ezoshosting.com/cs/

So there I was, snuggled in the leather seat of my brand new Ferrari I had
the oiled wooden gear shift in one hand, and the leather wrapped Momo in the
other. And, I had the stereo cranking _Born to be Wild_...
Only two problems, I was upside down, and under six feet of water...

[Jason L Tibbitts III]

> >>>> "AV" == Aaron VanDevender
> <sig(a)netdot.net&gt; writes: 
AV> I was trying to visit the website www.nap.edu (National Academies
AV> Press) using my FC6 desktop machine, but firefox just grinds on it
AV> indefinitely with "Waiting for www.nap.edu...";. I can telnet to
AV> port 80 of the site, and it connects, but after saying "GET /" it
AV> just hangs, and never returns anything.

Broken routers not handling TCP window scaling?  Try:
  echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
and see the thread starting at:
  http://lkml.org/lkml/2006/6/13/103

Unfortunately if this is the problem then disabling window scaling is
not really a proper solution; only fixing the broken network devices
works in the long term.

 - J<

[Aaron VanDevender]

On Wed, 2007-01-17 at 17:48 -0600, Jason L Tibbitts III wrote:
>  >>>>> "AV" == Aaron VanDevender
> <sig(a)netdot.net&gt; writes:
>  
>  AV> I was trying to visit the website www.nap.edu (National Academies
>  AV> Press) using my FC6 desktop machine, but firefox just grinds on it
>  AV> indefinitely with "Waiting for www.nap.edu...";. I can telnet to
>  AV> port 80 of the site, and it connects, but after saying "GET /" it
>  AV> just hangs, and never returns anything.
>  
>  Broken routers not handling TCP window scaling?  Try:
>    echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
>  and see the thread starting at:
>    http://lkml.org/lkml/2006/6/13/103 
Thanks, Jason. That did the trick. I'll let the owners know that they
need to fix their router and or server.


>  
>  Unfortunately if this is the problem then disabling window scaling is
>  not really a proper solution; only fixing the broken network devices
>  works in the long term.
>  
>   - J<
>

[Ed Greshko]

Aaron VanDevender wrote:

> > Broken routers not handling TCP window scaling?  Try:
> >   echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
> > and see the thread starting at:
> >   http://lkml.org/lkml/2006/6/13/103
>  
>  Thanks, Jason. That did the trick. I'll let the owners know that they
>  need to fix their router and or server. 
Actually, the problem is probably closer to you than to the owners of the
site.  I only say this since I can access the site you mentioned from here
in Taiwan with no trouble at all.

>  
>  
> > Unfortunately if this is the problem then disabling window scaling is
> > not really a proper solution; only fixing the broken network devices
> > works in the long term.
> >
> >  - J<
> >
>   

-- 
"In order to make an apple pie from scratch, you must first create the
universe."
		-- Carl Sagan, Cosmos

[Mike Wright]

Ed Greshko wrote:
>  Aaron VanDevender wrote:
>  
>  
> >>Broken routers not handling TCP window scaling?  Try:
> >>  echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
> >>and see the thread starting at:
> >>  http://lkml.org/lkml/2006/6/13/103
> >
> >Thanks, Jason. That did the trick. I'll let the owners know that they
> >need to fix their router and or server.
>  
>  
>  Actually, the problem is probably closer to you than to the owners of the
>  site.  I only say this since I can access the site you mentioned from here
>  in Taiwan with no trouble at all. 
Hi Ed,

I'm in San Jose, CA and can access the site from any of my boxes 
*except* for the fc6 ones.  Tried dillo, firefox, and telnet and all of 
them hang.  Telnet locked up so tight I had to open a separate xterm to 
kill it.

.02

>  
>  
> >
> >>Unfortunately if this is the problem then disabling window scaling is
> >>not really a proper solution; only fixing the broken network devices
> >>works in the long term.
> >>
> >> - J<
> >>
>  
>

[Aaron VanDevender]

On Fri, 2007-01-19 at 06:55 +0800, Ed Greshko wrote:
>  Aaron VanDevender wrote:
>  
>  >> Broken routers not handling TCP window scaling?  Try:
>  >>   echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
>  >> and see the thread starting at:
>  >>   http://lkml.org/lkml/2006/6/13/103
>  > 
>  > Thanks, Jason. That did the trick. I'll let the owners know that they
>  > need to fix their router and or server.
>  
>  Actually, the problem is probably closer to you than to the owners of the
>  site.  I only say this since I can access the site you mentioned from here
>  in Taiwan with no trouble at all. 
I sort of doubt it. Otherwise I'd see this problem all the time. I tried
it on 2 FC6 boxes which are 14 hops away from each other and got the
same result. Can you post (or just email me) a traceroute from your box
in Taiwan to www.nap.edu?

-Aaron