How to change ip address in Linux Ubuntu?

How to Change IP Address in Linux Ubuntu

Step 1: Connect to the Internet

Before we can change our IP address, we need to ensure that we’re connected to the internet. If you’re not connected to the internet, your computer will not be able to receive a new IP address.

• You can check your internet connection by opening a web browser and typing in a URL such as http://www.google.com.
• If you’re using a VPN or proxy, you may need to disable it to access the internet.

Step 2: Enable DHCP

The easiest way to change your IP address is to use a Dynamic Host Configuration Protocol (DHCP) server. This allows your computer to automatically obtain an IP address from the DHCP server.

• Open the Network Manager, which is a part of the Ubuntu package manager.
• Click on the "Edit" button next to your network interface (e.g. eth0).
• Look for the "DHCP" section and click on the "Edit" button.
• Check the box next to "Dynamic IP" and click "OK".

Step 3: Choose a New IP Address

Once the DHCP server is enabled, you’ll need to choose a new IP address. You can do this by clicking on the "Edit" button next to your network interface and then selecting "Advanced" from the dropdown menu.

• Click on the "IP" section and select the "New" button.
• Enter your desired IP address in the "Address" field.

Step 4: Save the Changes

Once you’ve chosen your new IP address, click "OK" to save the changes.

• If you’re using the Network Manager, click "Save Changes" to save your changes.

Step 5: Restart the Network

To apply the changes, you’ll need to restart the network service. You can do this by running the following command:

• sudo service networking restart

Step 6: Verify the New IP Address

After restarting the network service, you can verify that the new IP address has been applied by connecting to a website and checking your IP address in your web browser.

• Open a web browser and type in a URL such as http://www.google.com.
• If your IP address has changed, you should see your new IP address in the "Your IP Address" field.

Table: Common DHCP Server Configuration Options

Option	Description
upstream	Specifies the upstream server(s) that will provide DHCP services
lease	Specifies the lease duration for each IP address
shared	Specifies whether to share the DHCP server with other systems on the network
autostart	Specifies whether to start the DHCP server automatically on boot

Common DHCP Server Settings

Setting	Description
dnsmasq	A very lightweight DHCP server that can be used as a replacement for upstream DHCP servers
DHCPv4	A DHCPv4 service that allows you to configure IP addresses and hostnames for clients
DHCPv6	A DHCPv6 service that allows you to configure IP addresses and hostnames for clients
DNS	Specifies the DNS server(s) that will resolve domain names to IP addresses

Hypervisors and Virtual Machines

If you’re using a hypervisor or virtual machine, you may need to modify your DHCP server configuration to work with your virtual machine. You can do this by creating a new file with a name that ends with .conf and modifying the settings as needed.

• For example, you can create a file called dhcp.conf with the following content:

  conn "virtual machine" {
  
  ipaddr = "192.168.1.100"
  
  domain = "vm.example.com"
  
  }

• You can then configure your hypervisor or virtual machine to use the dhcp.conf file.

Common Issues and Solutions

Issue	Solution
dhcp refused	Check your IP address and make sure it’s valid.
dhcp not working	Check that your network interface is enabled and configured correctly.
DHCP server not starting	Check that the DHCP server is enabled and configured correctly.

Conclusion

Changing your IP address in Linux Ubuntu is a relatively simple process that can be done using a few different tools and techniques. By following the steps outlined in this article, you should be able to change your IP address and access the internet from your computer. Remember to always keep your IP address and other network settings up to date to ensure that your computer remains secure and connected to the internet.