Apple Mac OS X Server (Administrator’s Guide) - Manual (Page 533)

Firewall Service 533
7 If you choose “a range of IP addresses,” enter a subnet mask or click Use My Subnet to use
the computer’s subnet mask.
The resulting address range is displayed at the bottom of the window.
8 Click Save.
Searching for IP Filters
You can use the Find button in the IP Filter List window to search for filters that match
specific criteria. For example, you may want to see what filters you have set up for a specific
IP address.
To search the IP filter list:
1 In Server Settings, click the Network tab.
2 Click Firewall and choose Show Firewall List.
3 Click the Find button.
4 Choose your search criteria from the pop-up menus.
5 Click Find.
The search results appear in the bottom half of the window.
Viewing the Firewall Log
Each filter you create in Server Settings corresponds to one or more “rules” in the underlying
firewall software. Log entries show you the rule applied, the IP address of the client and
server, and other information.
To view the log for Firewall service:
1 In Server Status, click your server in the Devices and Services list.
2 Click the Log tab and choose System Log.
3 Look for log entries with the prefix “ipfw.”
Configuring Firewall Service
By default, Firewall service blocks all incoming TCP connections and allows all UDP
connections. Before you turn on Firewall service, make sure you’ve set up filters allowing
access from IP addresses you choose; otherwise, no one will have access to your server.
Important
If you add or change a filter after turning on IP filtering, the new filter will affect
connections already established with the server. For example, if you deny all access to your
file server, computers already connected to your file server will be disconnected.