Basic Router & Switch IOS configuration commands - CCNA beginner

Introduction

This tutorial provides a comprehensive guide on basic router and switch IOS configuration commands essential for beginners in Cisco's CCNA program. These commands are foundational for setting up and managing network devices, ensuring you can navigate and configure your router and switch effectively.

Step 1: Accessing Device Modes

To start configuring your router or switch, you need to access different command modes:

1. User EXEC Mode

   • Access this mode by connecting to the device. The prompt will display as Router> or Switch>.
   • Exit this mode by typing exit.

2. Privileged EXEC Mode

   • Enter this mode by typing enable. The prompt changes to Router# or Switch#.
   • Exit by typing disable or exit.

3. Global Configuration Mode

   • From the Privileged EXEC mode, type configure terminal. The prompt changes to Router(config)# or Switch(config)#.
   • Exit by typing exit, end, Ctrl+C, or Ctrl+Z.

Step 2: Configuring Line and Interface Settings

To set up user access and interface configurations, follow these steps:

1. Line Configuration

   • Access VTY lines configuration:

     Router(config)# line vty 0 15
     

   • Access the console line configuration:

     Router(config)# line console 0
     

2. Interface Configuration

   • To configure a specific interface, use:

     Router(config)# interface gigabitEthernet 0/0/0
     

3. Setting Passwords and Login

   • In line configuration mode:

     Router(config-line)# password cisco
     Router(config-line)# login
     Router(config-line)# transport input all  // for VTY lines
     

4. Configuring Interface IP Address

   • While in interface configuration mode:

     Router(config-if)# ip address 192.168.1.1 255.255.255.0
     Router(config-if)# no shutdown
     

Step 3: Configuring Router Settings

Next, set essential router configurations:

1. Setting Hostname and Banner

   • Change the hostname:

     Router(config)# hostname R1
     

   • Set a message of the day (MOTD):

     Router(config)# banner motd "No unauthorized access allowed!"
     

2. Configuring Passwords

   • Set the enable password:

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

3. Save Configuration

   • Save your running configuration to startup configuration:

     Router# copy running-config startup-config
     

Step 4: Testing Network Connectivity

You can test connectivity with the following commands:

• To check if a device is reachable, use:

  Router# ping 192.168.1.100
  

• To trace the route to a device:

  Router# traceroute 192.168.1.100
  

Step 5: Additional Helpful Commands

Consider adding these commands to improve your configuration experience:

• Disable DNS lookups to avoid delays from mistyped commands:

  Router(config)# no ip domain-lookup
  

• Prevent logging output from interrupting command input:

  Router(config-line)# logging synchronous
  

Conclusion

In this tutorial, we've covered essential IOS configuration commands for both routers and switches. Mastering these commands will prepare you for more advanced configurations and troubleshooting. As you continue your CCNA journey, practice these commands regularly to build your confidence and proficiency.