There appears to be some issues connecting an iPhone 3G (possibly other Apple iPhones & iPod Touch products using the new 2.0 firmware) to certain Wifi access points.
So far these issues appear to be limited to those using Linksys WAG54G V3 routers.
When attempting to join a wireless network, you receive an error saying “Unable to join network” followed by the name of your access point (SSID).
There are 2 known solutions to this problem.
1. Update the firmware to the latest version
From my post on the Mactalk.com.au forums:
Okay, I’ve upgraded the firmware on my Linksys WAG54GV3 and can confirm this has resolved the issue
I logged onto my router’s admin page and confirmed I was running version 1.0.22. Went to this link and selected Version 3.0 from the drop down box.
I then downloaded the firmware listed on the page (Firmware Annex A, version 10.0.46 Date: 2/07/2008 Size: 4.51 mb)
The actual firmware filename is called: WAG54GV3-U2-AnnexA-ETSI-v1.00.46-code.bin
I then logged back into my router and went to the Administration tab, and selected Firmware Upgrade and selected the file and clicked upload.
Waited for about 3 – 5 minutes for the firmware upgrade to complete, the router rebooted. My SSID was labelled the default (linksys) and there was no encyrption on by default. So i changed the SSID and turned on WPA2 and everything is working now
2. Change the Wireless mode to B only
A New Zealand user from the Apple Discussion forums (link) advises that you can also resolve this issue by changing the Wireless Network Mode on the router to 802.11B only. This can be achieved by going to the administration page on your wireless router and then clicking the following menu items: Wireless -> Basic Wireless Settings.
From there select B Mode. The draw back to this is that all devices are only able to connect to the network at B speeds.
The same user came back and confirmed they had gone to the Australian site and installed the firmware on their router and this also resolved the issue (even though the firmware wasn’t available in their country – New Zealand).
Please leave a comment if this resolved your issue, or if you have any further solutions to this problem. If you are having similar issues with a different router and have found a solution, please post the brand and model and the solution you have found.