Mac OS X Internet Sharing Problems, resolved

I was having problems with Internet Sharing on Mac OS X Snow Leopard. It was working at one time, and then it stopped. I would see from my Mac that it was getting a DHCP DISCOVER from my other computer, but the Mac would not give out a network address.

At long last, I figured out the problem. If perform this command:

$ sudo launchctl list | grep bootp
1550 - com.apple.bootpd

You will see that bootpd is actually running, but being com.apple.bootpd means it is running as the normal system bootpd server. You don't want that.

First, disable Internet Sharing. Then run this command:

$ sudo launchctl remove com.apple.bootpd

Then, re-enable Internet Sharing. You should now see something like:

$ sudo launchctl list | grep bootp
3423 - 0x100101440.anonymous.bootpd

This is the anonymous Internet Sharing version of bootpd. Now it all works.