So, you’ve got your hands on a Cisco router, and now you’re wondering: “How do I get this thing up and running?” Whether you’re prepping for a CCNA exam or setting up a small office network, learning how to configure a Cisco router from scratch is a fundamental skill. Let’s walk through it—step by step—with simple explanations, real-world insights, and real commands.
Before We Begin: What You’ll Need
Before diving into the configuration, make sure you’ve got the following ready:
- A Cisco Router: A 2800 series or any basic ISR (Integrated Services Router) is good for practice.
- Console Cable: Also known as a rollover cable, typically blue.
- Computer with Terminal Software: You can use PuTTY, Tera Term, or SecureCRT.
- Basic Networking Knowledge: Knowing IP addressing and subnetting helps a lot.
Connect the router to your PC using the console cable, and open your terminal emulator.
If you are using Cisco Packet Tracer, Skip this part and go straight to How to access Router CLI (Command Line Interface).
Use these serial settings:
Baud rate: 9600
Data bits: 8
Parity: None
Stop bits: 1
Flow control: None
Once connected, hit Enter a few times to wake the router.
How to Access the Router’s Command Line Interface (CLI)
Assuming you are connected to the router, When you connect to the router, you enter User EXEC mode. It looks like this:
Router>In networking devices like Cisco routers and switches, User EXEC mode is one of the modes of operation available when accessing the Command Line Interface (CLI).
User EXEC mode is the basic access level for a user to view the system’s configuration and perform a limited set of commands. It provides a read-only access level, meaning users cannot modify the router’s configuration or make changes to the device.
To configure the router you need to move to a higher mode which is Enable mode/Privileged EXEC mode.
Enable mode, also known as Privileged EXEC mode, is the second level of access in a router or switch CLI (Command Line Interface) after User EXEC mode.
Enable mode allows full access to all configuration and management commands. It also allows viewing of detailed system information and making configuration changes.
It is recommended to set a password for Enable/Privileged EXEC mode, Later in this tutorial you will also learn how to set privileged exec password.
The command for moving to Enable mode is enable.
Router> enablePress enter and Now you’re in Privileged EXEC mode, you can confirm it by the “#” sign.
Router#if you want to go back to User EXEC mode just Type disable to return to User EXEC mode.
As we are going to configure the router name, configure enable secret password, set MOTD banner and setting line console password we have to go to a higher mode known a Global Configuration mode.
In networking, particularly with Cisco devices, Global Configuration Mode is a command-line interface (CLI) mode that allows you to make system-wide changes to the device’s configuration.
From here, we will enter Global Configuration mode, to enter global configuration mode you must be at Privileged EXEC mode/Enable Mode . The command for entering Global Configuration mode is Configure Terminal. When at Enable mode type configure terminal and press enter.
Router# configure terminalYour prompt now changes to:
Router(config)#When you enter Global Configuration mode the prompt changes to (config)# .
We are finally at our desired mode to make and save changes to the router configuration. Now we will start basic configuration of a Cisco router step by step.
Set Hostname of the Router (Name Your Router)
Setting a hostname on a router (or any network device) is important for several reasons, both practical and operational. In a network with multiple routers, switches, and devices, unique hostnames help distinguish them easily. Instead of seeing Router> on all devices, you’ll see HQ-Router>, Branch1-Switch>, etc.
When logged into a device, the hostname confirms which device you’re configuring, reducing mistakes. Configuring hostname of a router helps prevent accidental changes to the wrong device in a multi-device environment.
Naming your router makes it easier to identify each routers by their names in larger networks. The command for setting hostname of a router is hotname (your desired name), in the below example we will set “HQ” name for our router.
Router(config)# hostname HQ
After this, your prompt updates to:
HQ(config)#
This small detail becomes incredibly useful when managing multiple devices.
Secure the Router with Passwords
Cisco routers don’t have passwords by default. That means anyone with physical access can change settings. Let’s fix that.
Cisco devices support Enable password and Enable Secret password, Both commands are used to set a password for accessing Privileged EXEC Mode (enable mode) on Cisco devices, but they differ in security:
Set Enable Password (Not Encrypted):
Enable password is Stored in plain text (or weakly encrypted) in running-config. We have listed this just for information so that you get familiar. Although Enable password is not recommended for security.
the command for setting enable password is “enable password yourPassword”.
HQ(config)# enable password hqpasswordIf you want to confirm that enable password is successfully set, go back to Privileged EXEC mode and type show running-config | include enable password.
HQ# show running-config | include enable password
enable password HQpassword (plain text if no encryption)
enable password 7 0822455D0A16 (Type 7 encrypted)If enable password is configured (not recommended), it may appear in plain text or weakly encrypted (Type 7). Type 7 is a weak encryption and can be decrypted easily with Cisco Type 7 Decryptor online tool.
Set Enable Secret Password (Encrypted Password)
This password protects Privileged EXEC mode. The enable secret password is always stored in hashed form (MD5/SHA) and cannot be reversed to plain text. To configure enable secret password type enable secret yourpassword and press enter.
HQ(config)# enable secret HQstrongPassword
Always use enable secret, not just enable password, because it encrypts the password, and cannot be decrypted.
Set Console Line Password
Setting a console line password helps secure access through the console port.This is for local access via the console cable.
HQ(config)# line console 0
HQ(config-line)# password consolepassword
HQ(config-line)# login
HQ(config-line)# exit
The above commands will configure a password for line console 0, You can learn more about setting console line password here. To confirm if a console password is successfully set read How to verify line console password.
Set VTY Lines Password OR Telnet/SSH Password
The VTY (Virtual Teletype) password helps protect remote access to a Cisco device using protocols like Telnet or SSH. These virtual lines enable network administrators to connect to and control the device from a remote location.
HQ(config)# line vty 0 4
HQ(config-line)# password remotepass
HQ(config-line)# login
HQ(config-line)# exit
The above command will set the same password for VTY lines 0,1,2,3 and 4, if you know the number of your router’s vty lines you can replace the 4 with your desired VTY lines. For better security, consider setting up SSH later instead of Telnet. For more info about VTY lines, the number of VTY lines and configuring VTY lines password, must read how to secure Telnet/SSH access with VTY lines password.
Set (MOTD) Message of the Day Banner:
A Message of the Day (MOTD) banner is a notification that appears when users connect to a network device like a router or switch. It’s commonly used to present key information or alerts—such as system messages or legal warnings—before login is permitted.
the command for setting Message Of The Day Banner is banner motd # your desired message#
HQ(config)# banner motd #Access to this device is restricted. Unauthorized access is prohibited.#
This message shows up before login and serves as a legal warning in many organizations. you may want to read all about Setting MOTD banner on cisco router and switch.
Configure IP Addresses for router Interfaces
Without an IP address, your router can’t talk to other devices. It is mandatory to set IP addresses for the interfaces which are to be connected to other network devices such as routers or switches. For a functioning network each interface should be assigned a unique IP Address.
Let’s configure GigabitEthernet0/0:
HQ(config)# interface GigabitEthernet0/0
HQ(config-if)# ip address 192.168.10.1 255.255.255.0
HQ(config-if)# no shutdown
HQ(config-if)# exit
Don’t forget
no shutdown. Interfaces are shut down by default.
To view interface status, go back to the Enable Mode and type:
HQ# show ip interface brief
This command is great for quick diagnostics and it will let you now if the interface is configured and working correctly as desired. Here is a detailed guide on how to Set IP Address forFast Ethernet and Serial Interface of Cisco Router.
(Optional) Set Default Gateway or Static Route
If your device needs to communicate with networks beyond its own local subnet, you can optionally set a default gateway or define a static route. This ensures the device knows how to forward traffic destined for other networks.
Set a Default Gateway
Default Gateway is typically used to route packets to external networks when no specific route exists. For setting a default Gateway you need to be at Global Configuration mode, the command for configuring a default gateway is:
HQ(config)# ip default-gateway 192.168.10.254
The IP address to set as your default gateway should be the IP address of the router or Layer 3 device that connects your local network to other networks, typically the internet or another subnet.
Add a Static Route
A static route is a manually configured route that tells a network device (like a router) how to reach a specific destination network. Unlike dynamic routing, which automatically updates routes, static routes remain fixed until manually changed by an administrator.
A default static route is a special type of static route that is used when no specific route to a destination network is found in the routing table. It acts like a “catch-all” route and is typically configured to forward all unknown traffic to a next-hop IP address (usually another router, such as an internet gateway). Configuring a default static route the command is:
HQ(config)# ip route 0.0.0.0 0.0.0.0 192.168.10.254
This tells the router where to send packets for unknown destinations. If you want to learn more about defining and configuring Static routes here is a detailed more in depth guide on How to Configure Static Routes on a router.
(Optional) Configure DNS
DNS configuration is optional but highly recommended for easier management. Without DNS, you must access devices via IP addresses only (e.g., ping 192.168.1.1 instead of ping HQ).
HQ(config)# ip name-server 8.8.8.8
8.8.8.8 is the ip address of Google DNS, required if you have access to internet. If the router needs to resolve public domain names (e.g., for NTP, syslog, or cloud services), DNS is required.
If you don’t want your router to have internet access but still want DNS for name resoultion you can setup a router as a DNS server, and you will map each IP address to each network device.
This helps when your router needs to access other network devices by their names instead of their IP Addresses.
Save Your Configuration
When we make any configuration changes to a router, all changes made are in running-configuration which is stored in RAM. If the router restarts, they vanish unless you save them.
HQ# copy running-config startup-config
Press Enter when asked for the destination filename. Make it a habit to use this command (copy running-config startup-config) as frequently as you make any configuration changes. For more about saving running configuration and startup configuration read How to Use Running Configuration and Startup Configuration efficiently on Cisco devices
How to Verify Router Configuration
HQ# show ip interface brief //display configurations of IP interfaces
HQ# show running-config // display the running-configuration from RAM
Use Ping To test network connectivity:
HQ# ping 192.168.10.254
If you see exclamation points (!!!), your connection is working. You can ping any device to see if it is connected to the HQ router. Here is a detailed guide on How to PING a Server, how to ping a network device and how to ping a router interface.
Troubleshooting Tips
- Interface down? Make sure you used
no shutdown. - Can’t access remotely? Recheck VTY line passwords and login settings.
- Still no ping? Check cables, IP addresses, and subnet masks.
And there you have it—your Cisco router is now configured and ready to route traffic. As simple as this may seem, these steps form the backbone of larger, more complex configurations. Practice makes perfect, so don’t just read this—get hands-on. Download Packet Tracer or use real hardware to reinforce the knowledge.
Frequently Asked Questions (FAQs)
Q: What’s the very first thing I should do on a Cisco router?
A: Set the hostname and enable secret to identify the device and secure admin access.
Q: Why is my interface still down after assigning an IP?
A: You likely forgot to run the no shutdown command.
Q: Is it better to use SSH than Telnet?
A: Yes, SSH is encrypted and much more secure than Telnet.
Q: Do I need to save after every change?
A: No, but make it a habit to save once your configuration is complete to avoid losing it.
