Configure Linux Network Interfaces and Enable Dynamic IP – Step-by-Step Guide

Locate Network‑Script Files

On a CentOS/RHEL system the network interface definitions reside in /etc/sysconfig/network-scripts/. You can list the directory and view the existing ifcfg-* files with:

# ls /etc/sysconfig/network-scripts/
# ls -l /etc/sysconfig/network-scripts/ifcfg-*

Typical output shows files such as ifcfg-ens33 (the primary Ethernet interface) and ifcfg-lo (the loopback).

Edit the Interface Configuration

Open the relevant ifcfg-ens33 (or the appropriate interface name) with a text editor and adjust the parameters. To enable a dynamic IP address, set BOOTPROTO=dhcp and ensure ONBOOT=yes. For a static address, specify IPADDR, NETMASK, GATEWAY, etc.

Example of a DHCP‑enabled file:

DEVICE=ens33
TYPE=Ethernet
BOOTPROTO=dhcp
ONBOOT=yes

After saving, restart the network service:

# systemctl restart network   # or: # service network restart

Virtual Machine Network Settings

Ensure the VM’s virtual network adapter is attached to a bridged or NAT network so that the guest can obtain an address from the host or external DHCP server. The following screenshots illustrate the VM network configuration and the edited ifcfg-ens33 file.

Dynamic IP Illustration

After restarting, the interface will obtain an IP address from the DHCP server, which can be verified with ip addr show or ifconfig.

Source: https://www.cnblogs.com/btcm409181423/p/17977163