Hello All Firstly I'd agree with everyone else that a software firewall is definitely not a replacement for a separate box. An old machine with a pair of network cards and linux/FreeBSD can go a long way towards more network peace of mind. Secondly I'd also agree turning off all unneeded services is a good idea. Not only because these services may allow an attacker to gain access to the machine, but also because they are likely to give away information about the system the machine is running. There is (generally) no disadvantage to disabling them, so why not do so? That does not however mean a software firewall is entirely useless. If your attacker gets root/admin access then it is completely useless, however if they only manage to gain normal user access then it can make their life harder.
The important thing with firewalls on servers is as important as filtering what goes into them is filtering what is allowed to come out. Theo Spears
