Are you a business, IT partner, or system integrator working with Cisco routers? Whether you’re maintaining a campus network, deploying for a client, or troubleshooting day-to-day, understanding Cisco routers is key.
Below, we answer the 15 most common and practical questions—with clear steps, context, and expert tips—so you can optimize your Cisco network with confidence.

How to Reset a Cisco Router?

Resetting a Cisco router can solve configuration errors or restore factory defaults.

  • Soft Reset: Reboot the router using reload in privileged EXEC mode.
  • Factory Reset:
    1. Power cycle the router.
    2. Press and hold the Mode/Reset button during boot.
    3. Use write erase and reload commands in CLI to clear configs.
      Tip: Always back up your configuration before performing a reset.

How to Enable IPv6 Routing on a Cisco Router?

IPv6 adoption is rising worldwide. To enable IPv6 routing:

  • Enter global config mode: configure terminal
  • Activate IPv6 routing: ipv6 unicast-routing
  • Assign IPv6 addresses to interfaces as needed.
    Note: Make sure your Cisco IOS version supports IPv6.

How to Factory Reset a Cisco Router?

A factory reset erases all custom configs and restores the router to default.

  • Use write erase in privileged EXEC mode.
  • Reboot with reload.
  • For devices with a reset button, follow the manufacturer’s guide.
    Warning: This process wipes all saved settings.

How to Disable DNS Lookup on a Cisco Router?

Cisco routers attempt to resolve mistyped commands as hostnames, causing delays.

  • Disable DNS lookup globally with: no ip domain-lookup

This saves time for engineers and avoids CLI “hangs”.

Which Cisco IOS Mode Displays a Prompt of ‘Router’?

Cisco routers operate in several modes.

  • The Global Configuration Mode prompt typically appears as: Router(config)#
  • Privileged EXEC is: Router#
    Knowing your mode ensures correct configuration and prevents errors.

What Is Stored in the NVRAM of a Cisco Router?

NVRAM (Non-Volatile RAM) stores the startup configuration file (startup-config).

  • This file is loaded at boot and determines the router’s behavior.
  • NVRAM does not store the running config (which is in RAM).
    Best Practice: Regularly back up your startup config off-device.

How Can I Configure a Cisco Router?

Basic steps to configure a Cisco router:

  1. Connect via console, SSH, or Telnet.
  2. Enter privileged EXEC (enable) and global config (configure terminal).
  3. Assign hostnames, passwords, and interface addresses.
  4. Set up routing, security, and management as needed.
    Tip: Always save your config (write memory or copy run start).

How to Upgrade Cisco Router IOS?

To upgrade Cisco IOS:

  • Download the correct image from Cisco.
  • Copy the image to the router (via TFTP, USB, or FTP).
  • Change the boot variable (boot system flash:image.bin).
  • Reload the device.
    Caution: Confirm compatibility before upgrading!

How to Check Interface Status on a Cisco Router?

Monitor interface health and troubleshoot with:

show interfaces
show ip interface brief

These commands display link status, errors, and IP assignments.

How to Assign IP Address on a Cisco Router?

Assign IP addresses using:

interface GigabitEthernet0/1
ip address 192.168.1.1 255.255.255.0
no shutdown

Repeat for each relevant interface.
Tip: Use descriptive names for clarity (description Uplink to Core).

How to Backup and Restore Cisco Router Configuration?

Backup:

  • copy running-config tftp:
  • copy startup-config tftp:

Restore:

  • copy tftp: running-config

Advice: Keep backup files safe, especially before upgrades or major changes.

How to Configure Static Routing on a Cisco Router?

Configure static routes for predictable traffic paths:

ip route 10.10.10.0 255.255.255.0 192.168.1.254

Use for default routes, branch links, or test labs.
Remember: Dynamic routing is better for larger, changing networks.

How to Configure DHCP on a Cisco Router?

Enable DHCP server for LAN clients:

ip dhcp pool LAN
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 8.8.8.8

Don’t forget to exclude static IPs:
ip dhcp excluded-address 192.168.1.1 192.168.1.10

How to Set Up Password Recovery on a Cisco Router?

Lost your password?

  • Physical access required:
    1. Reboot and enter ROMmon mode (interrupt boot sequence).
    2. Change config register to ignore startup-config (confreg 0x2142).
    3. Reset password, save, and restore config register.
      Tip: Only authorized admins should perform recovery.

How to Check Cisco Router Serial Number and Model?

Verify serial/model for support or asset management:

show version

Record this info for warranty, licensing, or technical support.

Output displays serial number, model, IOS version, and hardware details.

Similar Posts