- Linux: The Choice of Network Engineers
- Is Your Home System at Risk?
- What's Safe?
- Is Your Home System a Server?
- Are Broadband Connections More Vulnerable?
- What Ports are Open?
- Using Netstat to List Ports
- Is Windows File Sharing a Risk?
- Using a Port Scan to Test Your System
- Checking for Windows NetBIOS Risks
Using a Port Scan to Test Your System
If you want to know more about your system's vulnerability, do what crackers are doing to your system—scan the ports for security holes.
There are many scanners available. Just don't use them to scan someone else's computer. That's considered to be a hostile action and a sign that you are attempting to crack into their system. You could get into real trouble for doing that. Just use it to scan your own system and to help you find potential security holes.
Here are two scanners, one for Windows systems and one for Linux systems, that will do the job:
For Windows systems, Netcop Scanner is available for free from Netcop.
Netcop Scanner can be used to check for open IP ports on PCs and servers. To check your own computer, use the default host address of 127.0.0.1. Under Options, enter a range of ports. Entering 1 to 65535 will check every port on your system. The results will show a list of active ports and the associated services running on them.
Note that for Linux systems, nmap can be used to scan your system's ports. With the software installed, enter the command nmap localhost. This will produce a list of active ports on your system.