It used to be before the days of rampant remote scanning, you could just log connection attempts and bust 1000 people a day these days. Now that %99 of people remote scan, you're only screwing people over who got hacked. What I do is just close all ports to outside connections with my router, hell, go ahead and port scan me, I don't care.
I heard from a software that is a kind of ids call xp port listener taht is listening to your port and when someone scan or coenct to those they send a mesage that u choose for exmaple rou are now log so most of n00b will be freak and go away
I like qullims response the best. Dont connect ur machine to the net and you know your safe. but without hte net, is there a point to having a computer. Not in my mind. Hell without the net, i wouldnt know anything and wouldnt have any programs..
Backto the topic. I do two things to stop port scanning asses. First i have sygate running to block all ports except the ones im using.. It works very well. One guy tried port scanning me and it blocked him and told me his ip and gave me a link to email his isp so that i can get him banned... i like sygate..
The other thing i did was setup an ipsec protocol. I dont really know much about it (as im not a hacker or a networking guy) but there is a site that shows you how to set it up. what it does is block pings. It just shows a timeout to whoever tries to ping ur comp. IPSEC
Obviously everyone has mentioned disabling un-neccessary services and using a firewall. Personally when setting up a new box I will do all the service changes and firewall rules implementations and then scan my own pc via NMAP and Nessus. At least with Nessus you'll see any security holes in the services you are running and you can at least patch/fix them.
I absolutely agree with jimmy. Zone Alarm - Sux!!! The best solution to prevent port scanning is to install Agnitum Outpost 2.1 firewall. It' has a lot of interesting options you might like, especially Stealth Mode. Here is just some options out of many more:
Hiding your computer identity from hackers;
Stopping hacker attacks automatically;
Blocking private data from being transmitted;
Preventing mass-mailed worm infections; and
Removing ads and pop-ups.
Link: http://www.agnitum.com/
Prob been said, but here it is in a different light: Layered security is the key:
1) Hardware firewall/Router
2) NAT IPs
3) Disable ICMP
4) Software firewall and close unnecessary ports
5) If you absolutely must use network services (FTP, Telnet, finger, SQL, IIS, Apache, etc.), put them on a box that is dedicated to that cause and place them in a DMZ.
6) Don't do anything dumb like hosting a warez site on the same box that you have your financials on.
I used netpeeker some time ago, because it had some very nice features, like the option to limit your bandwith to a specified program running. You can also block data transfers wherever you want