Table 5 shows the Telnet server and client configuration required for a successful Telnet login.

Table 5 Telnet server and Telnet client configuration requirements

Device role

Requirements

 

Enable Telnet server.

 

Assign an IP address to an interface of the device, and make sure the Telnet

Telnet server

server and client can reach each other. By default, only interface

 

GigabitEthernet 0/0 is assigned an IP address (192.168.0.1/24).

 

Configure the authentication mode and other settings.

 

 

Telnet client

Run the Telnet client program.

Obtain the IP address of the interface on the server.

 

 

 

To control Telnet access to the device operating as a Telnet server, configure login authentication and user privilege levels for Telnet users.

By default, password authentication applies to Telnet login. To allow Telnet access to the device after you enable the Telnet server, you must configure scheme authentication.

The following are authentication modes available for controlling Telnet logins:

None—Requires no authentication and is insecure.

Password—Requires a password for accessing the CLI. If your password was lost, log in to the device through the console port to re-set the password.

Scheme—Uses the AAA module to provide local or remote authentication. You must provide a username and password for accessing the CLI. If the password configured in the local user database was lost, log in to the device through the console port and re-set the password. If the username or password configured on a remote server was lost, contact the server administrator for help.

Table 6 Configuration required for different Telnet login authentication modes

Authentication

Configuration tasks

Reference

mode

 

 

 

Set the authentication mode to none for the VTY user

"Configuring none

None

authentication for Telnet

interface.

 

login"

 

 

 

 

 

 

Enable password authentication on the VTY user

"Configuring password

Password

interface.

authentication for Telnet

 

Set a password.

login"

 

 

 

28