How to Configure IP Address in a Linux-Based Machine?

You can configure an IP address in a Linux-based machine using the network configuration files or the network command-line tools.

Using Network Configuration Files

Locate the configuration file: The configuration file location depends on the Linux distribution. Commonly, it is found in /etc/network/interfaces (Debian-based) or /etc/sysconfig/network-scripts/ifcfg-eth0 (Red Hat-based).
Edit the file: Open the file using a text editor with root privileges, like sudo nano /etc/network/interfaces.
Add or modify the IP address configuration:
- Static IP: Add the following lines to the file, replacing eth0 with your network interface name, 192.168.1.100 with your desired IP address, and 255.255.255.0 with your subnet mask:
```
auto eth0
iface eth0 inet static
address 192.168.1.100
netmask 255.255.255.0
```
- DHCP: If you want to obtain an IP address automatically from a DHCP server, use the following configuration:
```
auto eth0
iface eth0 inet dhcp
```
Restart the network service: After saving the changes, restart the network service using the command sudo systemctl restart networking.

Identify the network interface: Use the command ip addr show to list all available network interfaces.
Assign a static IP address: Use the ifconfig command to assign a static IP address. For example:
```
 sudo ifconfig eth0 192.168.1.100 netmask 255.255.255.0
```
Set the IP address permanently: Use the ip command to set the IP address permanently:
```
 sudo ip addr add 192.168.1.100/24 dev eth0
```
Verify the changes: Use the ip addr show command to verify that the IP address is correctly assigned.

Network Interface Name: The network interface name (eth0, wlan0, etc.) may vary depending on the system and hardware. Use the ip addr show command to identify the correct name.
Gateway Address: You may need to configure the gateway address in the configuration file or using the route command.
DNS Server: Specify the DNS server address in the configuration file or using the resolv.conf file.
Firewall: Ensure that the firewall rules allow the network traffic you need.