How can you block ports using command line (DOS)?

Question

Is there any way to block a port(i.e 6877 or ftp port 21) on windows computer using the command line.

In windows XP you can do this with windows firewall but is there any way to do this on Win2000 (if the computer is not connected to a router).
Any help would be appreciated.

Answer 1

Windows 2000 does not have a personal firewall built in like XP does, but you can use IPSec to block ports that you don't want others to connect to. As far as I know, however, you cannot do it from the command line, as your question asks. I imagine that it could be scripted, but I haven't found any good scripts for doing that.

Below is a nice little link to setting up IPSec as a firewall on Windows 2000 that you might find very useful. I won't repeat the web sites content here, but it's a great idea to setup a "firewall" for Win2k. Of course, this is a pretty drastic step because you have to define all of the traffic that you want in or out of your network interface. This can be extensive and can cause you a lot of headaches figuring out, plus, it's not going to tell you what's being blocked.. So, I offer an alternative.

If you want a true firewall on your machine, and one that's better than the Windows firewall, you can download one of the free firewalls and install it. The best that I know of are ZoneAlarm and Comodo, both linked below. Both of these firewalls let you decide what to let through. They do this by asking, you, the user, every time a new port connection is attempted either in our out of your PC. This protects you not only from outsiders, but also from Trojan Horses or other malware installed on your PC. For example, if you have spyware trying to download code or connect to a dial home server, you'll be prompted to approve or deny the connection attempt. Obviously, if you had to do this every time, it'd get anywhere from simply annoying to downright harassing, so the firewalls allow you to always let those services connect in or out by checking a box when it attempts to connect (always allow).

Hope this helps,
Don

Answer 2

Im afraid to say any ports are liable to attack as long as they are open..