If the program isn’t on the list-as in the case of new or upgraded software-OS X asks you whether to allow the program to accept incoming traffic. If the program is on the list, the firewall allows the connection. When a program asks to accept network traffic, a socket filter checks a list of programs that have been authorized to do so. Rather than using network ports and IP addresses to decide whether to allow a packet, it bases its decision on the application making the network request.
To ipfw, Leopard adds a new socket-filter firewall (also known as an application firewall). For instance, a packet-filtering firewall could accept file-sharing connections from IP addresses of your work network but not from other addresses on the Internet.
Packet-filtering firewalls like ipfw classify network traffic two ways: by type, using port numbers, and by origin and destination, using IP addresses. And don’t forget that any time you’re on a network-a coffee shop’s Wi-Fi system, for example-you’re exposed to anyone else on that network. But there are computers out there that do nothing all day but probe Net-connected machines for vulnerabilities it’s certainly possible that one will find yours. With millions of computers in the world, it might seem that the odds of your Mac being targeted are awfully small. There aren’t any such network vulnerabilities on Macs (that we know of) now, but many of Apple’s security updates specifically address network vulnerabilities. Years ago, a bug (long-since fixed) let attackers send Macs a so-called “ ping of death”-specially designed network traffic that could crash a system.
#How to edit mac os firewall ports mac os x
Mac OS X comes with not one but two firewalls of its own. They can keep criminals out while allowing legitimate network traffic in. Firewalls monitor and regulate the data moving on and off your computer or network.