IPvFour Configuration & Network Settings

###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