Re: 2.6.17 regression: Very slow net transfer from some hosts

[Stephen Hemminger <shemminger@osdl.org>]

On Tue, 11 Apr 2006 23:20:42 +0100
Daniel Drake <dsd@gentoo.org> wrote:

> John Heffner wrote:
> > This is almost certainly due to a buggy firewall that doesn't understand 
> > TCP window scaling.  I've usually seen this in the past with OpenBSD 
> > firewalls.  Do you have one of these in your path?
> 
> At home I'm behind a Linux gateway box currently running 2.6.15-rc6 - I 
> am connected through ethernet to that.
> 
> At my student house I am connected wirelessly to a Linksys WRT54Gv5 
> router (the model that doesnt run Linux).
> 
> I have reproduced it at both those locations (same ISP).
> 
> This is very familiar, and I just found the article I was thinking of: 
> http://lwn.net/Articles/92727/
> 
> I was also hit by that bug, on the same collection of websites, but that 
> particular problem was fixed for 2.6.8 or so. So I guess it is extremely 
> likely that my ISP has broken routers. nmap isn't able to identify the 
> OS of any ISP routers in my path.

We never fixed it, its kind of hard to fix other peoples equipment ;-)

> 
> It's a huge ISP over here, so contacting them over technical matters is 
> not easy...
> 
> Thanks,
> Daniel
> 

Turn off TCP window scaling, your performance will be limited but about
as good as you can get with a corrupting firewall in between.