I have a D-Link 502T with upgraded firmware, running in half-bridge mode. I've been using it with no trouble and with excellent speeds for a couple of years, partnered with a LinkSys WRT54G router (custom firmware.)
I just went and bought an Apple AirPort Extreme, so as to gain Wireless-N and the hard disk sharing features. Great! But it doesn't work. :/
The AirPort is configured to gain its IP address by DHCP, but keeps defaulting back to a private (169.254.81.206) address, regardless of what is actually being offered. I explain that in more detail shortly.
It's worse than that, even. If I disconnect the phone line such that the 502T doesn't get online, then it issues a local IP address of 10.1.1.2 for the AE. In the case of the LinkSys during this same condition, I am able to route through through to 10.1.1.1 to access the 502T's web-server, just as one would expect. But the AE isn't even doing that much! It just sits there saying "No internet connection" and won't route at all.
When the modem goes online, it _actually_ issues a DHCP IP address of 188.8.131.52 -- not 169.x.x.x. But it also tells the AE that the default router / gateway address is the same, 184.108.40.206 address. I suspect this is what is tripping up the AE, though the LinkSys doesn't have any problem with it. *Frustrating* and not at all what one expects from Apple, in my experience to date anyhow.
I updated to AE firmware from v7.5.1 to 7.5.2. But that made no difference what-so-ever.
I've read elsewhere on this same forum that others are using the Apple AE with a DSL2 modem in half-bridge mode without difficulty. More frustration/confusion. :/
Any assistance with this would be greatly appreciated. Thanks.