The Problem

Initially, the Airport Extreme will let computers connect, but will not let clients connect out to the internet. Problem extends beyond running standard Mac "Network Diagnostics" app. Tried:

- looking up and entering manual DNS settings for Virgin Media

- Googling for virgin media "airport extreme". Found this entry on Digital Spy.

Convinced that there's something wrong with the Airport Extreme base station. Every time I plug a computer directly into the NTL box, I get an address via DHCP and can surf out normally. What gives? Come back later for a second callout, armed with an Airport Express.

More fiddling with DNS settings and the like. After Googling proves fruitless, finally give up and call ultra-expensive support line. I explain the problem to the tech:

Me:

"I'm trying to hook up an Airport Extreme to the NTL cable modem, but it won't let me get online."

Tech:

"I can't help you with a PS2 or an XBox, that's not the area of my expertise."

Hoo boy...

The Solution
Basically, it comes down to this:

1. Unplug the power from the NTL cable modem. Wait for 5 seconds before powering it back up.

2. Unplug the Airport.

3. Plug the NTL cable modem back in. Wait until the Send/Recv lights are steady.

4. Connect the Airport to the NTL modem via the LAN port.

The tech confirmed with me that whichever device is plugged into the cable modem first will be the one to get the correct DHCP settings. This worked initially. We were able to surf out wirelessly using the Airport Extreme, but could not get a second computer to connect to the internet.

Redid the same procedure, this time using an Airport Express and was able to connect and surf with multiple laptops.