Every time I try to use Internet sharing
Wi-Fi, my Mac seems to create an ad hoc network, rather than using the currently connected wifi network. How do I make my Mac share to the current wifi network, and have a static IP?
Alternate wording: How to share the ethernet-based Internet connection of a Mac with a computer that is part of router-based wireless LAN without Internet connection?
Router is an AT&T modem/router that has been repurposed for LAN/wifi. The Mac is connected to an Apple Airport Time Capsule via ethernet, and the AT&T router via wifi. I need to share the ATC internet to the AT&T router's LAN network, while giving the Mac an IP address of