sebruiz.net » university

Websites which can’t handle TCP window scaling

Seb — Wed, 27 Jun 2007 10:03:26 +0000

I’ve run into a dead end in a process of debugging a website. Here’s the low-down.

A particular university website is needed for my (and my sister’s) study.
I have a 2 desktops and 1 laptop, all running kubuntu fiesty, on the same network, same dmz etc
Only the laptop loads the website
The website will load under windows on both of the desktops
Turns out, that the desktops will load the website, but very, very slowly (about 5 minute delay)

I have absolutely, no clue about how to continue debugging and hopefully fixing the problem. Does anybody have any suggestions that I could use to try and get this up and running again?

nb: it doesn’t seem to be ipv6 causing the problems.

Update:
A big big thanks to Jonathan Brugge and LukyLuke who have already solved my problem. Turns out that my university couldn’t be arsed hiring decent software developers (or paying for a decent system). The website simply doesn’t handle scaled TCP windows properly. There are two solutions:

echo "0" > /proc/sys/net/ipv4/tcp_window_scaling
Caveat: this causes no window scaling to be applied on all sites, so the better method is to apply on a per ip basis:

ip route add IP.ADD.RE.SS/32 via window 65535

(found on the openSUSE wiki)

Busy Busy Bee Weekend

Seb — Tue, 17 Apr 2007 00:54:36 +0000

The last week has been really busy, in that really great and satisfying way. On Saturday Mish and I went for a hike in the Royal National Park, on a wonderfully sunny day and we spent the day running along cliff edges. There were fishermen (no doubt fishing) off ledges a good 20m above the sea water, and you’d know why if you saw: the water was chaotic and smashing along the rock walls.

Sunday morning I went for a surf with Tony and Dani – great fun at Bondi beach until disaster struck and Tony has his board snapped in two . In the afternoon I found some time to fix my KDE4 build and got into some Amarok hacking again, working on the new-and-totally-cool context view. We’re using QGraphicsView which is so yummy and fun to work with.

Yesterday I spent the day at work and was totally surprised when the Tomcat/J2EE application that I’m working on “just worked” when I threw it onto Linux. I was shocked that it worked since the webapp was compiled under Windows, and with a different version of Java. Still very slow, but it worked.

Finally, last night I went to the Red Hot Chili Peppers concert, which was fantastic. Great music, and a much greater ‘funk’ in their live versions of the newer song releases. The only really terrible thing was the support act, Har Mar Superstar, an overweight hairy man who is convinced of his “sexiness” and did a striptease down to his underwear. I thought it was hilarious however, and was laughing the entire set .

How am i supposed to pass…

Seb — Sun, 04 Mar 2007 11:41:55 +0000

When my two subjects are:

Biomedical Systems Analysis
Biological Signal Analysis

For crying out loud, they have the same lecturer, are on the same day and have probably already jumbled up the names?

help!

… and here’s to reality

Seb — Sun, 04 Mar 2007 11:40:13 +0000

I got back from holidays, then I got a full time job, and then two weeks later I left because the contract was totally unfair and crap. Then I re-enrolled in uni 1 day a week. This last week was spent practically living on the beach with my surfboard as my only shelter, eating blue bottles and drinking from the shower taps. My arms and shoulders hurt from all the surfing – feels good.

Tomorrow I start another job, working part time three days a week. Looks fun, at least.

thesis due soon!

Seb — Fri, 27 Oct 2006 23:13:56 +0000

I’ve been a little busy the last couple of weeks since returning from San Francisco because of the impending deadline for my thesis. The word count has nearly hit 15,000 – a pretty good effort if you ask me. Once Tuesday comes and goes, I’ll be a much happier man.

My thesis has been based on application work for the bionic eye project at my university, which is really cool and exciting, particularly since Qt 4.2 is my development platform!

I consider my thesis to be my testbed and experience for upcoming Qt4 development. The new QGraphicsView architecture is wonderful to work with, and I also just started a conceptual Amarok context browser written with a QGraphicsView framework. Details coming soon when I have some more time!

Oktoberfest!

Seb — Thu, 19 Oct 2006 11:24:35 +0000

Tonight was the yearly Oktoberfest at uni! Lots of fun, with great beer and music. Infact, a band which I really like played tonight, 78 Saab, for free!

I love uni!

obsession

Seb — Thu, 24 Aug 2006 23:38:01 +0000

A man with his five year old son walks into the store I work at. After browsing the shelves for a few minutes, he picks up an xbox game and walks to the counter. By this point the little boy has decided that his new favourite game should be bought to. Sensing a tantrum, the father quickly turns to the boy and cuts in – “ANAKIN! Don’t you even think about…”

I know its mean, but I couldn’t contain my laughter!!

In other news, I’ve changed thesis topics because my attempt at a kernel module for some highly scientific camera turned out to be a dead end. Thankfully, I’ve landed a new topic for a Qt4 interface, which will be nice to work with something familiar.

In Amarok news, 1.4.2 has just been released. I’ve been a little too busy lately to put any substantial amount of work in, but I sure am looking forward to jumping right in for all of the Qt4 work which needs to be done.

Back to Uni

Seb — Sun, 23 Jul 2006 12:10:14 +0000

I realised that this is the eighth time I’ll be starting a new session at uni! Scary how quickly time goes, and now i’ll be working on my thesis too!

Thesis report

Seb — Wed, 10 May 2006 05:59:39 +0000

The cursor blinks. The words do not appear…