Ip addresses and internet sharing

Question

My iBook is connect to the internet via a wireless network, and I have an ATA (Analogue Telephone Adpater, a Vonage-type box) connected to the ibook via ethernet cable. The iBook is set up to share the airport internet connection to its built in ethernet port, and the wireless router has the relvenat Voip ports forwarded to the iBook's ip address. This all works fine.
With this set up the iBook gets its ip address from my wireless router, and the ATA is picking up an ip address from my iBook. The wireless router is handing out addresses in the range 192.168.1.(1-100) to computers on the network and the iBook always hands out an address to the ATA that is 192.168.2.xxx
Is there anyway to force a change in the architecture of the local network to permit the ATA to get an ip address from the wireless router rather than the iBook? i.e. let the ibook work as a bridge rather than a router. I have tried simply setting the ATAs ip address manually to be inside the range of ip addresses handed out by the woreless router, and specifying the wireless router's ip address as the gateway, but with this configuration the ATA cannot see the internet.

Answer 1

Yes, I've seen the cure in this particular Forum some months ago, (unfortunately I didn't bookmark it!).
If it helps, the pseudo router in the Mac always hands out x.x.2.x addies, which has been a bugaboo if you had any other x.x.2.x device in the mix, somewhere a few months after that discovery, some Guru here posted exactly what you need... sorry I can't help you more!