The telnet server-source command specifies a source interface for a Telnet server.
The undo telnet server-source command restores the default setting.
By default, the source interface of a Telnet server is not specified.
| Parameter | Description | Value |
|---|---|---|
| -i loopback interface-number | Specifies a loopback interface as the source interface of the Telnet server. | - |
Usage Scenario
By default, a Telnet server receives connection requests from all interfaces so that the system is vulnerable to attacks. To enhance system security, you can specify the source interface of the Telnet server. This sets a login condition and only authorized users can log in to the Telnet server.
Prerequisites
Before running the telnet server-source command, ensure that the loopback interface to be specified as the source interface has been created. If the loopback interface is not created, the telnet server-source command cannot be correctly executed.
Configuration Impact
After the source interface is specified, the system only allows Telnet users to log in to the Telnet server through this source interface, and Telnet users logging in through other interfaces are denied. Note that setting this parameter only affects Telnet users that attempt to log in to the Telnet server, and it does not affect Telnet users that have logged in to the server.
Precautions
After the source interface of a Telnet server is specified using this command, ensure that Telnet users can access the source interface at Layer 3. Otherwise, the Telnet users will fail to log in to the Telnet server.