Firewall doesn't seem to work at all

[ksgant]

I have Leopard and have all the software updates. I'm on 10.5.1

Seems that the firewall settings don't do anything. I've put it now on "Set access for specific services" yet it does nothing. Doesn't block anything, doesn't ask for permission before using a program or anything. I've even put Firefox as an application and set it to "block incoming connections" but it does nothing....Firefox plows right through and loads pages up like before.

I've even put it on "Allow only essential services" and it still doesn't block anything. Firefox again loads everything. Can even play Warcraft with that checked. I doubt Warcraft is an "essential service".

Do I have to set the settings then log out and back on? Do I need to reboot to get the settings to hold? What am I doing wrong?

 

[Makosuke]

I think you're misunderstanding how a firewall works, and what those settings mean.

As you said, you set Firefox to "block incoming connections"--meaning that if some outside computer tried to talk to FireFox through an open port, it would not be allowed to. Firefox can, however, receive data that it has asked for, which is how 99.99% of what you do on the web works--your browser says "give me file X" and the server says "here is file X".

For the most part firewalls are meant to let that traffic through--that's what it does. Otherwise, it's basically the same as yanking the network cable, since if the firewall doesn't let requested data come in, all you're doing is sending out signals and ignoring the response, which does nothing at all from your end.

It sounds like you want something like LittleSnitch, which tracks all network traffic in BOTH directions, for example an app "phoning home" (which is entirely OUTGOING traffic, not coming in).

Perfect example of how a firewall DOES work would be a peer-to-peer app. Your computer is sitting there listening to port, say 5150. When somebody outside tries to search your computer for shared files, it connects to port 5150 and says "Hey, wanna tell me what you've got?" If a firewall is blocking that port (or that specific app) it stops the signal on the way in--the local app never hears the request, and so the external computer never gets a response. If there is no firewall, or that port and app are open, then the request gets through and the local app responds "Hi, here's what I have."

Hope that helps.

 

[ksgant]

Yes, I think that does help.

I've set the firewall on "Set access for specific services and applications" now and have stealth mode enabled.

and yes, I suppose Little Snitch would be the other end of it. Leopard firewall for incoming, little snitch for outgoing.

Thanks for your help.