NTL translucent proxy fun
Posted by Graham Stratton Fri, 11 Aug 2006 14:33:00 GMT
A few days ago I spent about a day debugging a problem where I had set the IP address of certain domains in my /etc/hosts on my local machine, in order to test those domains on my new server before the DNS was switched over, and spent most of a day debugging that.
It turned out that NTL have a ‘transparent’ proxy, which routes web requests to the ‘correct’ server, so it didn’t matter where I attempted to send the requests. The fact that it (obviously, really) intercepted telnet sessions to port 80 didn’t make me any less confused. And I think it’s slightly buggy, I’m sure there was a class of requests that got to the right place.
Sadly today I got caught by this again. I spend a long while trying to debug my apache config, trying to set up a default page for people accessing my machine by IP or by an unknown name.
I’ve recently had a client transfer their domain to my server, so I tried to access that, but no matter how much I tried I kept getting my photography site. Accessing by IP address returned the same site. But the default site is the first in the server setup. Hmmm.
Enter NTLs translucent proxy. Firstly, the DNS change for the new domain doesn’t seem to have reached their servers yet. Hang on, why don’t they send me to the old server, then? Ah, because in the old DNS setup www.domain.tld existed but domain.tld didn’t; now both of them do. No, that doesn’t quite work.
It seems that if I try accessing by IP address the proxy is adding headers for some domain hosted on that server. Very strange. If I try accessing the same site from my other server it works fine.
