Internet Sharing grayed out

Try disabling the internet sharing before you try to edit the settings.

First set the port you want to share from and too. The Option and box is then active: no longer grayed out.

Click on Internet Sharing in the list in Sharing and you should see on the right-hand side:

Share your connection from:

and

To computers using:

Next to that label should be a list of currently unused ports, tick whichever one you want to turn on then you will be able to tick Internet Sharing on

The only thing I can suggest is to try different channels in AirPort Options. Automatic usually ends up on channel 1 which may be getting inteference. Failing that the only thing is to try moving the iBook around to find a sweet spot.

Once you've filled out the AirPort Options you should be able to tick Internet Sharing in the list on the left.

I'm having this same issue trying to connect my new iMac to an iBook. The iMac is connected to RoadRunner over Ethernet and I'm trying to share the connection over airport to the iBook. It won't let me turn on sharing because it says a port hasn't been selected over which to share the connection

Please, how does one choose and turn on a port?

Thanks for responding. Yes, I've chosen Share your connection from: Built in Ethernet and To computers using: Airport

But, internet sharing still stays Off. Do I have to do anything with the Airport Options tab? Currently the channel is set to automatic and the network name matches the iMac's computer name.

Could this have anything to do with the information transferred from the iBook when I set up the iMac. The iBook was using a dial-up connection but I've used the Airport on it when I've traveled. It's running Tiger, if that's an issue. The broadband on the iMac worked like a charm as soon as it was installed the other day.

Yes, I discovered the problem was the iMac was set to sleep after a couple of hours and that's what was preventing it from allowing the internet sharing. After changing it never to sleep I was able to tick internet sharing and get the green light for it.

But...now I'm having trouble with iBook picking up the signal. They're sitting side by side. The Airport is set to the computer to computer network of my iMac but still can't get connected. Any thoughts?

Thanks again! I was able to connect them with Firewire but still haven't been able to using Airport. Also tried moving around and that was a no go, but will try changing the channel, too.

Is there a way to determine if the Airport is working correctly on the iMac? or if there's something wrong with the iBook?

Well, I'm not sure exactly what happened, but everything seems to be working now.

Glad it's sorted out.