Visited the owner and sure enough the laptop would not connect properly. However their other laptop was OK, their Ipad was OK and my netbook would connect OK which had never been on their network.
The laptop was getting an IP address from the router which was the DHCP server. The router was saying that the laptop was connected as it was in the list of connected devices. However the laptop connection was saying that it was "Local" only and there was no little globe on the connection near the clock. You could ping the laptops IP address ok but if you pinged the default gateway (the router) laptop said there was no connection.
Stripped out the wireless connection, and tried connecting again, no joy. Checked the router, which was a BT Home Hub 3 nothing seemed to be amiss. Stopped the router working on 802.11 B G and N and let it work on just B and G, still the same. Gave up and took the laptop away for further examination.
The Toshiba connected first time and no problems getting on the internet on my network. Very strange.
Trawled the net looking for similar issues. There seemed to be a lot pointing towards an issue with Vista and DHCP Broadcast flags. However checking the solution and the registry, it would appear that the registry entry had been changed probably in one of the service packs I am guessing.
It was a bit difficult trying to fault a laptop that works perfectly on your network but does not work on the laptops owners network. So I came up with a list of "logical" things to try the next time I visited
- Try it on an ethernet cable
- Try a USB wireless dongle
- Try resetting the router to factory defaults
- Compare the ipconfig /all output with my netbook
- Try a different access point plugged into the HH3 router
- Try a different router
- Disable IPv6 - I'm getting desperate now!
- Compare Wireshark logs of the Toshiba and my netbook connecting to the router - Really really desperate!!
So back out to try and get the laptop working and work my way through the logical list. However I didn't need to. When I tried connecting to the router everything worked, a miracle? Well no. Before I left home I updated the Atheros wireless driver from the default one that was installed when Vista was re installed.
So it would seem that the Vista default drivers for the Atheros wireless work on some routers and not on others. Looking at Windows Updates in the control panel, there was a failed optional update for the Atheros Wireless. The error code meant the update failed due to there being a more recent version already installed on the laptop, this was the one that I installed before I left home.
So the moral of the story is don't assume that the drivers are OK just because it works on your network!