I will try to make this tutorial as general as possible, as I can give you the REDHAT way of doing things as concerns to where REDHAT base systems maintain there networking files or Gentoo based systems...etc

1. Lets start with the basics....
   • To view all your active network interface
     run this command "ifconfig"

     sabayon-dynasty ~ # ifconfig
   eth0      
   Link encap:Ethernet  HWaddr 00:0E:35:94:FB:D9
   inet addr:192.168.101.5  Bcast:192.168.101.255 Mask:255.255.255.0
   inet6 addr: fe80::20e:35ff:fe94:fbd9/64 Scope:Link
   UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
   RX packets:2656195 errors:0 dropped:19 overruns:0 frame:0
   TX packets:1762149 errors:0 dropped:0 overruns:0 carrier:0
   collisions:0 txqueuelen:1000
   RX bytes:3593125256 (3426.6 Mb)  TX bytes:144856589 (138.1 Mb)
   Interrupt:10 Base address:0xe000 Memory:e0200000-e0200fff
     

   • Or you can be specific and run (ifconfig and the interface name)"ifconfig eth0"
2. Setup your network interfaces!
   • REDHAT WAYFor redhat based systems you will have to do this (assuming your network interface is eth0 and using DHCP)..
     "vi /etc/sysconfig/network-scripts/ifcfg-eth0"
     
     

     DEVICE=eth0
     BOOTPROTO=dhcp
     HWADDR=00:E0:81:24:CQ:82
     ONBOOT=yes
       

   • Now for a static ip setup (assuming eth0)..
     "vi /etc/sysconfig/network-scripts/ifcfg-eth0"
     

     
     DEVICE=eth0
     BROADCAST=192.168.101.255
     BOOTPROTO=static
     HWADDR=00:E0:81:24:CQ:82
     IPADDR=192.168.101.5
     NETMASK=255.255.255.0
     NETWORK=192.168.101.0
     ONBOOT=yes
     TYPE=Ethernet
     

   • Now run this "service network restart" or run this "ifdown eth0" to make sure the interface is down, then "ifup eth0"
3. GENTOO WAYFor gentoo based systems you will have to do this.
   • (assuming your network interface is eth0 and using DHCP)..
     "vi /etc/conf.d/net"
     
     

     
     config_eth0=( "dhcp" )
     dhcp_eth0="nosendhost"
     dns_domain_eth0="linuxdynasty"
       

   • Now for a static ip setup (assuming eth0)..
     "vi /etc/conf.d/net"

     
     config_eth0=( "192.168.0.2 netmask 255.255.255.0 broadcast 192.168.0.255" )
     routes_eth0=("default via 192.168.0.1")   # IPv4 default route
       

   • Now run this "rc-update add net.eth0 default" so that it is in the default run level.
   • Now to get the interface up and running...
     "/etc/init.d/net.eth0 restart"