Sure--the linux firewall supports all kinds of options, and can be configured in many different ways. Unfortunately, all the complexity of the options can be a bit daunting at first for newcomers.
Not for the squeamish, but this provides a pretty detailed overview of the linux firewall ("iptables") system: http://www.linuxhomenetworking.com/w...Using_iptables
If you're not used to doing a lot of command-line-based /non-GUI sort of work you might find one of the linux firewall-specific distributions to be more your cup of tea. IPCop and Smoothwall come to mind... there's also *BSD-based m0n0wall and pfSense. One of these would be installed on a freestanding machine--separate from your file/application server.
Some mainstream linux distributions include built-in firewall managements tools, such as Novell SuSE and Redhat. Depending which linux distribution your company is using, you might very well already have an iptables configuration tool present on the system.
Hope this helps.