Ch 25 Networking

Linux Networking  :  Scope of this document will be How to assign IP , Networking Tool , Ports and Misc Network settings 

    IP Assigning using GUI/TUI Mode :

          1. system-config-network : and follow the screen and update IP, DNS and Hostname related stuff 

          2. system-config-network-tui : this will open Terminal Graphical windows which can be operated using 

             Space Arrow and Enter key same as above method IP,DNS and Hostname.

     IP Assigning using File Editing :

                          

         Fedora / Redhat / Centos and all other Linux distribution following Redhat release has following  Network Directory Structure.

         #  /etc/sysconfig/network-scrips/ifcfg-eth[N]  e.g ifcfg-eth0  

        

         #vi /etc/sysconfig/network-scrips/ifcfg-eth0

            DEVICE=eth0

            NM_CONTROLLED=no

            ONBOOT=yes

            IPADDR=10.21.22.162

            BOOTPROTO=on

            NETMASK=255.255.0.0

            DNS2=10.21.2.14

            TYPE=Ethernet

            GATEWAY=10.21.1.1

            DNS1=10.21.2.220

            IPV6INIT=no

            USERCTL=no

            HWADDR=00:50:56:9C:BE:9B

            PREFIX=16

            DEFROUTE=yes

            IPV4_FAILURE_FATAL=yes

     If you want to add Permanent Virtual IP to your system  Here are the steps:

     # cp /etc/sysconfig/network-scrips/ifcfg-eth0 /etc/sysconfig/network-scrips/ifcfg-eth0:0

     # vi /etc/sysconfig/network-scrips/ifcfg-eth0:0

            DEVICE=eth0:0

            NM_CONTROLLED=no

            ONBOOT=yes

            IPADDR=10.21.22.163

            BOOTPROTO=on

            NETMASK=255.255.0.0

            DNS2=10.21.2.14

            TYPE=Ethernet

            GATEWAY=10.21.1.1

            DNS1=10.21.2.220

            IPV6INIT=no

            USERCTL=no

            HWADDR=00:50:56:9C:BE:9B

            PREFIX=16

            DEFROUTE=yes

            IPV4_FAILURE_FATAL=yes

     

    Two Fields are Updated DEVICE and IPADDR Restart Network Service you will get 2 IP from same machine and this will be persistence after reboot.