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| Protect your network with port banners |
| Before breaking into your network, attackers will scan your system to get as much information as |
| possible. With port scanning, an attacker may even attempt to connect to your computer to see a list |
| of services running on your computer. |
| For instance, an attacker might notice that you're running a Windows 2000 Server with IIS 5.0 and |
| no service pack. This information can help him or her discover unpatched holes on your system. |
| Anyone can get this information because services that are running usually respond with a certain |
| amount of detail. For example, when you connect to a Web server, the Web server will respond with |
| the software name and version. |
| Try it yourself by following these steps: |
| Type "telnet your_server 80" and replace "your_server" with a Web server's address. |
| Press [Enter] three times. |
| You'll get a response similar to this: |
| Server: Microsoft-IIS/5.0 |
| As you can see, you obtained the Web server version without much work. If you were an intruder, |
| you could search the Internet for any known vulnerabilities for this version and try to hack into the |
| Since port banners reveal a lot of information about your computers and the software running on |
| them, you'll probably want to change them. |
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