Networking in Red Hat Linux / Fedora

Networking is easy to configure in Red Hat Linux / Fedora

Following is network configuration files for Fedora / Red Hat Linux

/etc/sysconfig/network-scripts/ifcfg-XXX

Ifcfg-XXX where XXX is type of adapter e.g ifup-ethX, ifup-wireless, ifup-ppp. This file has information of gateway used and hostname. This file is used during boot process. Typical configuration of this file is as below

DEVICE=eth0

BOOTPROTO=none

ONBOOT=yes

PREFIX=24

IPADDR=10.0.1.27

File contents are simple

  1. DEVICE provides device name, exception to this ppp which is dynamically allocated
  2. BOOTPROTO provides for protocol which can be
    • none — No boot-time protocol should be used
    • bootp — The BOOTP protocol should be used.
    • dhcp — The DHCP protocol should be used.
  3. ONBOOT is logical if yes device is activated at time of boot and if no nothing is done at time of boot.
  4. PREFIX is bits of subnet mask. A 24 bit subnet mask is equivalent to 255.255.255.0
  5. IPADDR is static ip address for device

/etc/init.d/network reads file during boot process and checks status of adapter which has ONBOOT=yes. If its running nothing is done, else adapter is started by calling ifup script for that device.  /etc/init.d/network does not react to changes which are done after boot for that you have to manually run ifdown and ifup.