Networking Redhat Linux

A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections. Data is transferred in the form of packets.

Configuration Files

File
Description
/etc/resolve.conf
List DNS servers for internet domain name resolution.
/etc/hosts
Lists hosts to be resolved locally (not by DNS).
/etc/nsswitch.conf
List order of host name search. Typically look at local files, then NIS server, then DNS server.
/etc/sysconfig/network-scripts/ifcfg-device
Specify TCP network information.

~]# mii-tool - Media in dependent interface tool it will check for the connectivity, speed of device.

~]# system-config-network   -           to configure the IP Address in CLI and GUI
~]# setup                                   -           to configure the IP and DNS, it will work in CLI and GUI
~]# ifconfig                               -           to see the IP details
~]# ifdown <Ethernet>           -           it will bring down the interface
~]# ifup <Ethernet>               -           it will bring UP the interface

To Assign Temporary IP Address
~]# ifconfig <device name> <IP Address> <Netmask> <Gateway> - this will assign a IP temporarily after reboot it will not be there.
~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0 – to assign permanent IP Address



~]# vi /etc/hosts            -           to add entry in this file follow as below


~]# hostname   -           to add temporary Hostname and see the hostname

Using NEAT Command

~]# neat -     it is used to assign the IP Address in GUI mode. (It will not work in CLI)

Double Click on the Device name



Nickname: Provide the device name
Address:        <Enter IP Address>
Subnet mask: <Enter Netmask>
Gateway:       <Enter Gateway>

Click on OK



Using DNS tab you can provide

Hostname: <Enter FQDN>
Primary DNS: <Enter Primary DNS Address>
Secondary DNS: <Enter Primary DNS Address>

Using neat we can also create virtual network devices

~]# service network restart  - to restart the network service
~]# service network reload   - to reload the network configuration settings
~]# service network start/stop – to start and stop the service


Using Setup Tool


Using Setup command you can configure
1.    Authentication Configuration
2.    Firewall Configuration
3.    Keyboard configuration
4.    Network configuration
5.    System services
6.    Time zone configuration
7.    X configuration

In this topic we are going to talk about Network configuration

~]# setup           -           to enter into the setup tool
 
Select Network Configuration and hit Enter (click on Run Tool)



After entering into the Network configuration all the Network devices (Ethernet cards) you can able to see. Select the card which you want to modify the settings and hit Enter.

 
Provide all the required information such as IP Address, Net mask and Gateway Address. Click on OK

Then restart/reload your network service so that it will affect the new configuration changes.

Enjoy...... Waiting for your Comments