ITServices
Queen's UniversityMac OS X 10.4 Firewall
The firewall is a security program that prevents unwanted users and/or programs from accessing your computer. Located under Sharing options, the Mac OS X firewall provides you with the option of blocking remote access to programs that use the network and/or the Internet.
Requirements
In order to complete the instructions below, you will need:
- Administrative Access to local computer
Why do I need it?
You need the firewall to stop hackers from gaining access to your computer and using it to send spam or server porn or illegal software from your computer. That Mac computers are not prone to virus attack is a false assumption. While the percentage of Mac computers attacked may not be as high as PCs attacked by viruses, worms, adware and spyware, they are susceptible to malicious programs as well. Therefore, it is essential that you protect your machine. While there are commercial firewalls available for the Mac, the Mac OS X’s built-in firewall offers a free solution to this problem.
How it works
The built-in personal firewall monitors all incoming network traffic (both through the internet as well as the intranet) to your computer. All inbound connections are denied access to your computer by the firewall, except for those programs and connections you explicitly permit, on services that are turned on. On the Services options tab under Sharing, there is a list of services that need either the Internet or a shared network to function:
- Personal File Sharing – Gives users on other computers, access to folders that are public on your system
- Windows Sharing – Allows Windows users access to public folders on your machine through the SMB/CIFS protocol (Server Message Block / Common Internet File System), as well as allow them to use shared printers
- Personal Web Sharing – Allow users of other computers to view web pages in the sites folders on your computer
- Remote Login – Gives access to users from other computers using SSH (Secure Shell) and SFTP (Secure File Transfer Protocol)
- FTP (File Transfer Protocol) Access – Exchange files with users on other computers using FTP applications. It is better to use SFTP above if possible, a good SFTP client is Fetch.
- Apple Remote Desktop – Similar to windows remote desktop, this program allows users on a different computer to access your machine.
- Remote Apple Events – This allows applications on other Mac OS X or Mac OS 9 computers to send events and AppleScript to your computer
- Printer Sharing – Allows other people to use printers connected to your computer
How to enable it
Before enabling the firewall for sharing programs, it is necessary that you understand that you can only turn on firewall for services that are turned on. Though there is a default setting for the firewall in Mac OS X, it is recommended that you set this up yourself. To turn on firewall for any of the services, follow the steps below:
1. Open the System Preferences (this can be found in the docking station).
2. Under Internet & Network, click on Sharing, and the following window will be opened:
3. Click on the firewall tab, between Services and Internet.
4. All you need to do now is click on Start, and the firewall starts preventing network communication on all the services and programs below, with the exception of those services enabled.
- If you use other network applications (iChat, MSN etc.) you may need to select New and add a rule for that service as well. Some rules exist for common applications, if the rule does not exist, check out http://www.portforward.com/ for information about ports required for the application in question.
How to disable it
To disable the firewall, all you have to do is click Stop, when the firewall is shown as On:
Copyright Queen's University
Kingston, Ontario, Canada K7L 3N6 613.533.2000