Setting Up Linux Networking

Most of the networkConfiguration is kept in files; therefore, adjusting these settings is simple.

To start, you can use three management commands:

When you’re working with network interfaces, there are two additional files you need to know:

ifconfig                       Displays the IP address and other interface-related information

route                          Enables you to view or change the routing information on the system

system-config-network                  Provides a menu-driven utility for network configuration tui

/etc/sysconfig/network                 This file contains gateway and hostname information.

/etc/sysconfig/network-scripts      This directory contains all the interface config files for your system.

# cat /etc/sysconfig/network

NETWORKING=yes

NETWORKING_IPV6=yes

HOSTNAME=RHEL01

# cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0

BOOTPROTO=dhcp

HWADDR=08:00:27:30:74:AA

ONBOOT=yes

DHCP_HOSTNAME=RHEL01

TYPE=Ethernet

Interface details can be edited:

Step 1. To bring the single interface down, use ifdown:

# ifdown eth1

Step 2. To restore the interface that you just brought down, use ifup:

# ifup eth1

Use the ifconfig command to display your current IP address

Syntax: ifconfig [options] [interface]

Options:

netmask             MASK Specifies the netmask for the interface

hw ADDRESS        Sets the MAC address of the interface

up                     Brings up the interface

down                    Bring down the interface

Shutting down interface eth0:                                 [ OK ]

Shutting down interface eth1:                                 [ OK ]

Shutting down loopback interface:                          [ OK ]

Bringing up loopback interface:                               [ OK ]

Bringing up interface eth0:

Determining IP information for eth0... done.          [ OK ]

Bringing up interface eth1:                                       [ OK ]