[Sheflug] ECN D'oh!

[nospam [at] alexhudson.com]

Guys,

I spent about three hours yesterday at work (Saturday - I know :( - we've
moved offices, and I'm attempting to put things back together !!) banging my
head against a wall.

Not literally ;) But, we have an ISDN system I wanted to get working. It's a
NetGear 348 ISDN router, which is a nice system, built in masquerading,
DHCP, call accounting, all sorts. And I got it working, kind of. Using my
laptop to debug the connection, I could ping, and I could resolve DNS, so
that meant at least ICMP and UDP were working. However, I could not get
anything useful (web, mail, etc) working _at all_. First time I ever saw
anything like it in my life. Tested it on a Windows PC - of course, the
Windows PC worked fine with it :(

Well, last night it came to me - 2.4 Explicit Congestion Notification.
Turned it off (echo "0" > /proc/sys/net/ipv4/tcp_ecn). Everything now works.
This is absolutely the first time it has ever caused me a problem (hence me
not recognising the problem, nor thinking of the solution - I realised it
was only a TCP problem, but didn't really make the connection). Has anyone
else seen this problem 'in the wild' as it were? I'm sure I haven't.

Cheers,

Alex.
-- 


----- End forwarded message -----

-- 
___________________________________________________________________

Sheffield Linux User's Group - http://www.sheflug.co.uk . 
To unsubscribe from this list send mail to 
shef-lug-request@list.sheflug.org.uk with the word
"unsubscribe" in the body of the message. 

  GNU the choice of a complete generation.