Disordered HTML packets?

July 20, 2007 9:10 PM

What is wrong with our Windows 2003 webserver? The web pages it serves are usually (but not always) missing some of the HTML when viewed on other machines, playing havoc with the layout. What's going on?

Network guru filter: one of the webservers I manage and develop for at my office has developed a very strange problem after a change in the network interface.

Web pages served by it (PHP 4, Apache 2.1, Windows 2003 Server) sometimes are missing pieces of the HTML or even show the HTTP header in the middle of the page. If the same page is repeatedly reloaded, about 1/3 of the time it will display correctly. The problem pages all use AJAX as far as I can tell.

This application drew no complaints before the switch. It was attached to two separate networks through two ethernet cards. Now it is using only one card and the settings on the router or something are supposed to limit the access of one group of users who were previously segregated onto one network.

Some more data points:
1) on my multiboot Windows XP workstation the problem shows in both in IE and Firefox.
2) when the workstation is booted into Linux the same pages show no problems.
3) again, no problems with the same pages when viewed in either browser running on the server itself.

Unfortunately I am a web developer, not a network engineer, so I'm not even sure what keywords would describe this problem, let alone know what it could be caused by. The network staff at my office have not been able to help much yet, although they're coming in next week to take a look. I'm now looking at using ethereal to try and see if packets are somehow being disordered, but I'm really over my head. Any suggestions would be much appreciated!

posted by jarsyl to computers & internet (8 answers total)

What happens if you turn off the fancy segregation?
posted by rbs at 9:50 PM on July 20, 2007

Every time I see something like "PHP 4, Apache 2.1, Windows 2003 Server" I die a little.

Seriously though, a couple things come to mind:

The fact that the page renders properly under linux makes me wonder if perhaps Windows is cacheing something to do with the old network setup which is somehow screwing with connection to the server. It may even be that a simple reboot would clear up the problem for the other clients, but then your workstation should have been working properly after you booted over to linux and back.

Like rbs above, I'd try to lose the network segmentation for the time being and see if the page will render properly without it.
posted by jjb at 10:05 PM on July 20, 2007

erm ... perhaps there is a routing table problem on the server ... like a static route associated with the old network / network card ... that needs to be removed since the connection was removed. It is a longshot ... but ...
posted by jannw at 9:20 AM on July 21, 2007

are the calls to the ajax pages via the same domain? Was the web server previously load balanced?
posted by fishfucker at 10:09 AM on July 21, 2007

It could just a bad router or network card. This actually happened to me and swapping out the router (a crappy Linksys, mind you) fixed the truncated / messed up pages.
posted by y10k at 10:12 AM on July 21, 2007

Thanks for all the suggestions! Unfortunately I don't have access to the settings that control the segregation (and wouldn't know how to manipulate them if I did) but I'll mention this to any network staff who decide to visit.

Other problematic workstations would definitely have been rebooted by now.

The AJAX calls are to the same domain. There hasn't been any load balancing on the webserver.

I'll definitely take a look at swapping the network connection to the other (now unused) LAN card and see if that helps. We can probably locate a spare router to try as well.

As for the Windows 2003 Server bit, I wish I had control over what that server is running (my other webserver there runs Linux) but it is heavily used as a Windows fileserver. Alas I don't think a suggestion to move to samba would go over well with my boss.
posted by jarsyl at 8:24 AM on July 22, 2007

The network staff finally came by, presented us with some options and then left us to try them out. First we tried replacing the router, then switching to the other LAN card as y10k suggested. The latter fixed the problem! No more broken web pages, hooray!

Thanks everyone!
posted by jarsyl at 6:27 AM on July 24, 2007

Also, it seems entirely possible that the defective LAN card was always broken and it was never noticed because only non-privileged users were accessing it via that interface and then only rarely.
posted by jarsyl at 6:34 AM on July 24, 2007