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Configure Telnet on a Cisco Router with Local Username and Password

In this tutorial, we will walk through the steps to configure Telnet access on a Cisco router using a local username and password. This setup allows administrators to remotely manage the router using Telnet, ensuring secure access through authentication mechanisms. Below, we’ll explain the scenario, the configuration process, and verify the setup.

Scenario Overview

We have a network setup as shown in the topology:

• Router (R1) with IP address 192.168.10.1/24 on interface GigabitEthernet 0/0/0.
• PC1 with IP address 192.168.10.10 and subnet mask 255.255.255.0.
• We will configure the router with a hostname, an enable password, and a local username and password for Telnet access.

Other Types of Telnet Configuration

1. Configure Telnet on a Cisco Switch with Only a Password
2. Configure Telnet on a Cisco Switch with Local Username and Password
3. Configure Telnet on a Cisco Router with Only a Password
4. Configure Telnet on a Cisco Router with Local Username and Password

Configuration Steps

1. Access the Router and Enter Configuration Mode
   First, access the router’s CLI and enter privileged EXEC mode by typing enable. Enter global configuration mode with configure terminal.
2. Set the Hostname and Enable Secret
   Configure the router’s hostname to identify the device on the network:

   Router(config)#hostname R1

   Set the enable secret password to secure access to privileged EXEC mode:

   R1(config)#enable secret DragonICT

   Here, “DragonICT” is the password for enabling privileged mode.

3. Configure the Interface
   Navigate to the interface GigabitEthernet 0/0/0 and assign an IP address:

   R1(config)#interface gigabitEthernet 0/0/0
   R1(config-if)#no shutdown
   R1(config-if)#ip address 192.168.10.1 255.255.255.0
   R1(config-if)#exit

4. Create a Local Username and Password
   Define a local user with a privilege level and a password:

   R1(config)#username admin privilege 15 secret class

   In this configuration, “admin” is the username, and “class” is the password.

5. Configure VTY Lines for Telnet Access
   Access the VTY line configuration mode and enable local login:

   R1(config)#line vty 0 15
   R1(config-line)#login local
   R1(config-line)#transport input telnet
   R1(config-line)#exit

   The command login local ensures that Telnet access is authenticated using the local username and password we set earlier.

6. Save the Configuration
   To save the configuration to the startup configuration, use the following command:

   R1(config)#do write

Verification

To verify that Telnet access is working correctly:

1. Test Telnet Access from PC1
   On PC1, open a command prompt and initiate a Telnet session to the router:

   C:\>telnet 192.168.10.1

   You should be prompted to enter the username and password. Use the credentials:

   • Username: admin
   • Password: class
2. Successful Login
   If the configuration is correct, you will gain access to the router’s CLI. You can verify that you have successfully logged in by executing a simple command like show ip interface brief.

This configuration ensures that only authorized users can remotely access the router using Telnet, providing a secure method for managing the device. Remember that Telnet transmits data in plaintext, so for more secure environments, consider using SSH instead.

By following these steps, you have successfully configured Telnet on a Cisco router using a local username and password, secured access with an enable secret, and verified the configuration through testing.