10.4: Fix firewall blocking of Mail under internet sharing

Aug 16, '05 07:31:00AM

Contributed by: liz4cps

Tiger only hintWe just put in an PowerMac at a retired relative's house running Tiger connected to the internet via DSL. Normally, the PowerMac will only be used as a standalone machine, but it does have an AirPort card. While we're visiting, we want a wireless network so we can use our notebooks to access the internet.

So, today, we tried it. Web surfing worked immediately. Mail, however, would not work. We figured out that the firewall running on the PowerMac was blocking ports Mail needed, but then it took a bit of playing around to make it work. We turned on logging and found blocked ports that might be used by Mail, told the firewall to allow them, and got things working. Since there was already someone using a port scanner on us, we removed some of the ports from the allowed list that we weren't sure we actually needed there, and things still worked.

Here's what we did...

  1. Go to System Preferences -> Sharing -> Services and turn on "Personal Web Sharing" (if you don't, you'll be prompted to later), and click the "Start" button to turn on the service, if necessary.

  2. Under System Preferences -> Sharing -> Firewall, click "New..." and create an "other" listing with these ports: Click "OK" and the new service should be on. Our firewall was already on, of course. If yours isn't, it should be OK to turn it on.

  3. Under System Preferences -> Sharing -> Internet, choose the options to share your connection from "built-in Ethernet" and turn on sharing to computers using AirPort.

  4. Click "AirPort Options" to create an AirPort network. For a quick network, I leave the computer name, use "automatic" for the channel, enable encryption, and put on a password. To make it more permanent, I'd also turn on MAC filtering, though I'd have to look up how (at home, we have an AirPort Base Station).

  5. Click Start
You may also have to turn on AirPort; I do that via the AirPort icon on the menu bar. To add that icon, go to System Preferences -> Network, show AirPort, and click on the AirPort tab.

I think needing to add the ports to the allowed list on the Firewall is new with Tiger, as we have created such networks in the past without noticing this problem. The last time was a few years back, and we can't remember if the computer connected via AirPort was actually used to send or receive email in the short time we used the wireless net; I can't imagine that it wasn't. Hopefully Apple will at least add an email option to the services pane at some point.

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