Re: I can't access some site with Mozilla SOLVED

["Christopher L. Everett" <ceverett@ceverett.com>]

Felix C. Stegerman wrote:

> Christopher L. Everett wrote:
>
> > OK,
> >
> > I git this problem only once in a while.  Otherwise useful site that I
> > can't access that give me "connection refused" errors when Moz or
> > IE on a Windows box behind the same firewall as me works fine.
> >
> > Here are 2 sample URLS:
> >
> > http://www.mwave.com/
> > http://www.egain.com/
> >
> > I realize that most likely these turkeys have a braindead (MS ISA? )
> > firewall in place.  So how do I deal?
>
> I think you may have a problem with ECN.

Heh, this fixed it!

> "Please note that kernel.org uses Explicit Congestion Notification 
> (ECN), as defined in RFC 3168. Some broken firewalls or gateways may 
> have problem connecting to ECN-enabled servers. Please contact your 
> firewall or gateway vendor for necessary updates."
>
> I had the same problem connecting to my own router through it's 
> web-interface, thanks to ECN being enabled by default in kernel 2.6.x.
> If I re-enable ECN, I can't access mwave.com either.
> If I disable it again, I can.
>
> To check your settings:
>  cat /proc/sys/net/ipv4/tcp_ecn
> This will probably output: 1
>
> To disable it, run:
>  echo 0 > /proc/sys/net/ipv4/tcp_ecn
> And try connecting to e.g. mwave.com again.
>
> To change this permanently, add:
>  net/ipv4/tcp_ecn=0
> to /etc/sysctl.conf
>
> Regards,
>
>
> Felix


--
Christopher L. Everett

Chief Technology Officer                               www.medbanner.com
MedBanner, Inc.                                          www.physemp.com