Test the Telnet function in combination with Windows 7 Firewall

Telnet is a common remote logon and management tool for system administrators. It is integrated into the system as a standard system component in Windows 2000/XP/2003/Vista. However, by default, the telnet service is disabled. Generally, you only need to run services. MSC open service management, find the telnet service item, set its Startup type to "Manual" or "automatic", and then start the service to use it. However, in Windows 7, you cannot find and enable the telnet service according to the above method. How can I retrieve the Telnet function of Windows 7?

1. hidden reasons

In fact, Telnet cannot be found in the service manager. instead of abandoning Telnet in Windows 7, telnet is not installed in Windows 7 by default. This is the first time Microsoft has removed default system components from its personal system via Telnet, which is similar to Windows Server 2008. I think Microsoft should do this for security reasons. After all, Telnet data is transmitted in plaintext, and attackers can easily obtain sensitive information through sniffing. Based on security considerations, we recommend that you use a more secure and encrypted SSH remote management method.

2. Install Telnet

However, we do not have to discard food for some reason. It is very convenient to telnet as an individual user. The installation of Telnet in Windows 7 is slightly different from that in Windows Server 2008. You can perform the following operations. Click Start> Control Panel>Program"," In programs and functions ", find and click" open or close windows functions "to enter the WINDOWS function Settings dialog box. Find and check "Telnet client" and "Telnet Server", and click "OK" to complete the installation. In addition, we can also install "TFTP client" and "Internet Information Service" through this wizard. (Figure 1)

Figure 1 function activation and Installation Wizard

After the installation is complete, the telnet service is disabled by default. You also need to execute "START" → "run" and enter services. MSC to open the Service Manager. Find and double-click the telnet service item, set the start mode to "Manual" (more secure, enable only when needed), and then "start" the service and "OK" to exit. (Figure 2)

Figure 2 Service Attributes

3. Set Telnet

The seamless integration of Telnet and system firewall in Windows 7 enables custom control and enhances the security of Telnet. Click Start> All Programs> Advanced Security Windows Firewall to enter the firewall settings window. Click "inbound rules" in the left-side pane, find "Telnet Server" in the middle pane, right-click the rule and select "properties" to go to its attribute settings window. Click the "General" tab. By default, the firewall allows all Telnet connections.

Based on security considerations, select "allow the connection if it is sevure" (only secure connections are allowed), and then you can customize security rules. Click the "computer" tab. Under this tab, you can set the computer that authorizes the telnet connection and the exception computer. Click the "Scope" tab. Under this tab, you can set local IP addresses and remote IP addresses to control the telnet connection. Click the "user" tab, under which we can add users who can remotely Telnet. (Figure 3)

Figure 3 Telnet Properties

4. connection test

To verify whether telnent settings are valid in Windows 7, we telnet to the Windows 7 host through a Windows visata host for testing. Enter the "Telnet 92.161.100" command in the command line of Vista and press Enter. The system prompts you to enter the user name (the above settings only allow JP users to log on) and password. Then you can see that the logon is successful. It indicates that telnet is successfully installed and our firewall settings take effect. (Figure 4)

Figure 4 connection test

conclusion: although telnet is not secure, it is seamlessly integrated with Windows 7 firewall, its security has been greatly improved. In fact, all network-related tools in Windows 7 can be closely integrated with firewalls