### IPv4 Configuration & Network Settings ###

Network Support:
  1. Boot system into a multi-user mode
  2. /etc/modprobe.conf - contains alias and reference to module(s) to be loaded in order to provide networking
  3. Linux decides if the interface is DHCP or static by viewing the contents of:
   a. /etc/sysconfig/network - networking=yes|no, IPv6_Support, Default Gateway, etc.
   b. /etc/sysconfig/network-scripts/ifcfg-eth0 - contains ifup, ifdown, and ifcfg-* scripts
   c. /etc/init.d/network - main service

service network status - checks networking

system-config-network-* - network interface configuration

Note: Either update your net configuration manually from the shell, or using the 'system-config-network*' tools to avoid losing settings


/etc/resolv.conf - DNS configuration file
/etc/hosts - static list of hosts

IPv4 Aliases:
 1. ifconfig eth0:1 192.168.75.11
 2. ifconfig eth0:2 10.168.76.11

Note: To ensure that aliases persist do the following:
 1. cp /etc/sysconfig/network-scripts/ifcfg-eth0 ./ifcfg-eth0:1
 2. Modify ifcfg-eth0:1 to reflect aliased IP

Note: Aliases do NOT work with DHCP interfaces

ifconfig eth0:2 del 10.168.76.11 - removes the virtual interface

IPv6 Config:
 Features:
  1. Auto-configured by default gateway (router)
  2. fe80:: - link-local address (loopback/local subnet address)
  3. 2002:: - 6to4 address, that can be configured based on IPv4 embedded address, using HEX notation

ping6 -I eth0 fe80::
traceroute6 - used to trace routes on IPv6 networks