I currently share my DSL connection using a wireless router with DHCP disabled, and dnsmasq running on a Mac Mini serving DHCP & DNS. This setup is important because I have clients doing PXE boot, and I need the control over DHCP that dnsmasq provides. There is also a Time Capsule on the network that's used purely as a backup device; its wireless functions are disabled.

The wireless router is starting to get a little flaky, and since it doesn't support 802.11n I'd like to replace it. Rather than buying a new router, I'd like to just use the Time Capsule. But I see no way to disable its DHCP server; when I set the connection type to PPPoE, it insists on serving DHCP.

Is there any way to use Airport PPPoE with a DHCP server elsewhere on the network?