Network setup for RedHat GNU/Linux 7.0-7.2

This document tries to explain how to configure a machine running RedHat GNU/Linux to be usable on our Laptop Network. The rest of this document assumes that you are configuring the eth0, though you can clearly substitute any ethernet interface you plan to use to connect to the network. If things aren't clear please let us know.

Network config for eth0

Start a terminal window, become root and run:

    netcfg

In the netcfg window check that eth0, is shown with dhcp enabled and that any user is allowed to start/stop it.
Select eth0 then click on the Edit button to bring up the Edit window.
netcfg main window

In the Edit window ensure that the Allow any user to (de)activate interface box is checked and the Interface configuration protocol is set to dhcp.
Hit the Done button and the Save button in the netcfg window (and finally the Quit button to exit).

edit eth0

Basically this creates/edits the file:

    /etc/sysconfig/network-scripts/ifcfg-eth0

to contain something like:

    DEVICE=eth0
    USERCTL=yes
    ONBOOT=no
    BOOTPROTO=dhcp
    BROADCAST=
    NETWORK=
    NETMASK=
    IPADDR=

so you can just edit the files directly if you prefer. The important lines here are BOOTPROTO=dhcp which tells the system to use a DHCP client and USERCTL=yes which says to allow any user (not just root) to start/stop the interface.

The reason for having ONBOOT=no (or Activate interface at boot time unselected), is that one some systems an attempt to bring up a network interface may cause booting to hang while it waits for a dhcp reply. No reply will come if the machine isn't plugged into a suitable network. This can cause confusion so is best avoided.

Starting up networking

After setting up eth0 any logged in user can run the rp3 (may also be called from a menu item or by clicking on an icon or similar). This will bring up a control window.

Selecting eth0 and clicking OK will cause it to open a status monitor window for eth0. rp3 main window

The eth0 monitor window has a button on the right the center of which shows the current network status (green means up red means down). There is also a little bar graph of recent traffic load on the left.
You can start or stop the interface by clicking on the right hand button which will bring up one of the confirmation windows below.

eth0 status

start eth0

stop eth0

For those who prefer to stop/start networking from the command-line the commands:

  ifup eth0

and

  ifdown eth0

respectively will start or stop the eth0 interface (these commands are probably in /sbin/ of course).

Other configs

This setup has been tested on RedHat 7.0 and tested on 7.1 and the configuration should be very similar for 7.2. For RedHat 7.3 and above you need to use the neat tool instead of netcfg see the RedHat GNU/Linux 7.3 description for details. descriptions)

For details on how to configure other GNU/Linux distributions please refer to the documentation provided with the system or contact your local computer support staff.

Selecting eth0 and clicking OK will cause it to open a status monitor window for eth0.

The eth0 monitor window has a button on the right the center of which shows the current network status (green means up red means down). There is also a little bar graph of recent traffic load on the left. You can start or stop the interface by clicking on the right hand button which will bring up one of the confirmation windows below.