Basic Cisco Router Security Configuration

How to Secure a Cisco Router Basically?

Security is an important concern for a network engineer. How can a network engineer provide security of a router? In this Basic Cisco Router Security Configuration lesson, we will talk about, how to Secure a Router. We will see the Router Security Steps one by one. Let’s start.

Disabling Unused Ports

For a router basic security configuration, the first step is shutdowning all the unused ports. If you are using a port, it needs to be up. But if you don’t use any ports, then always disable (administratively down) these unused ports.

Shutdowning, in other words, disabling a port is very easy. You can do it with “shutdown” command under that interface.

Router(config)# interface fastethernet 0/0
Router(config-if)# shutdown

Enable and Enable Secret Passwords

The second important router security step is passwords. You should use passwords on your router.
Here, there are two passwords: Enable and enable secret password.

Enable password stores the password in clear text format. So, it is easy to see it. But ,enable secret password stores password in encrypted mode. So, it is more secure.

To encrypt all passwords in a router/switch, you can use “service pasword-encryption” command.
Let’s see how to configure this paswords on a router.

Router(config)# enable password 12345
Router(config)# enable secret 12345
Router(config)# service password-encryption

Configuring Telnet Access Password

Telnet is not a secure way of connecting to a router. But if you use telnet to connect a router, you should use telnet password.

To configure Telnet Access with password, you can use the below commands.

Router (config)# line vty 0 4
Router(config-line)# password 12345
Router(config-line)# login

Here, firstly we enter the line vty mode and then set the password string with password keyword. After that, we enter login command to activate it.

Configuring Console Access Password

Like telnet, you also need to configure Console Access password for a secure router. To do this, firstly you need to enter line console mode and then set the password string. Again, with the login keyword, you can activate it.

To configure Console Access with password, you can use the below commands.

Router(config)# line console 0
Router(config-line)# password 12345
Router(config-line)# login

Configuring Auxiliary Port Access Password

Aux Port Access password is rarely used. But like telnet and console, you can configure its password in line aux mode.

To configure Aux Port Access with password, you can use the below commands.