Configure Telnet on a Cisco Switch with Only a Password

Telnet is a protocol used for remote management of network devices such as switches and routers. In this guide, we will configure Telnet on a Cisco switch with a simple password-based authentication. This setup is useful for basic remote administration but should be used cautiously due to its lack of encryption.

Network Topology

Telnet on a Cisco Switch with Only Password Topology
Telnet on a Cisco Switch with Only Password Topology

Our network consists of:

  • A Cisco Switch (S1)
  • A PC (PC1)
  • A direct connection between the switch and PC
  • IP Addressing:
    • Switch VLAN 1: 192.168.10.1/24
    • PC1: 192.168.10.10/24

Benefits of Configuring Telnet

  • Enables remote access to the switch from a PC.
  • Allows basic switch management without needing a direct console connection.
  • Useful for quick troubleshooting and configuration changes.

Step-by-Step Configuration

Step 1: Access the Switch CLI

Connect to the switch via the console and enter privileged mode:

Switch>en
Switch#enable

Step 2: Enter Global Configuration Mode

Switch#configure terminal

Step 3: Set a Hostname

Assign a hostname to the switch for easier identification:

Switch(config)#hostname S1

Step 4: Set an Enable Password

This ensures secure access to privileged EXEC mode:

S1(config)#enable secret InfraCyberPwd

Step 5: Configure VLAN 1 with an IP Address

Since Telnet requires an IP address, configure VLAN 1 as the management interface:

S1(config)#interface vlan 1
S1(config-if)#no shutdown
S1(config-if)#ip address 192.168.10.1 255.255.255.0
S1(config-if)#exit

Step 6: Configure Telnet Access

Enable Telnet on virtual terminal (vty) lines:

S1(config)#line vty 0 15
S1(config-line)#password pwdTelnet
S1(config-line)#login
S1(config-line)#transport input telnet
S1(config-line)#exit

Step 7: Save the Configuration

Ensure the settings persist after a reboot:

S1(config)#do write

Step 8: Test the Telnet Connection

On PC1, open the command prompt and initiate a Telnet session:

C:\>telnet 192.168.10.1

Enter the password pwdTelnet when prompted.

Conclusion

This setup allows remote switch access via Telnet with a password for authentication. However, Telnet is not secure as it transmits data in plaintext. For a more secure approach, consider using SSH (Secure Shell) instead of Telnet.