Working With Profiles - Red Hat ENTERPRISE LINUX 4 System Administration Manual

Chapter 17. Network Configuration
Tip
To change lookup order, edit the /etc/host.conf file. The line order hosts, bind
specifies that /etc/hosts takes precedence over the name servers. Changing the line
to order bind, hosts configures the system to resolve hostnames and IP addresses
using the name servers first. If the IP address cannot be resolved through the name
servers, the system then looks for the IP address in the /etc/hosts file.

17.10. Working with Profiles

Multiple logical network devices can be created for each physical hardware device. For example, if you
have one Ethernet card in your system (eth0), you can create logical network devices with different
nicknames and different configuration options, all to be specifically associated with eth0.
Logical network devices are different from device aliases. Logical network devices associated with the
same physical device must exist in different profiles and cannot be activated simultaneously. Device
aliases are also associated with the same physical hardware device, but device aliases associated
with the same physical hardware can be activated at the same time. Refer to
Aliases"
for details about creating device aliases.
Profiles can be used to create multiple configuration sets for different networks. A configuration set
can include logical devices as well as hosts and DNS settings. After configuring the profiles, you can
use the Network Administration Tool to switch back and forth between them.
By default, there is one profile called Common. To create a new profile, select Profile => New from
the pull-down menu, and enter a unique name for the profile.
You are now modifying the new profile as indicated by the status bar at the bottom of the main
window.
Click on an existing device already in the list and click the Copy button to copy the existing device
to a logical network device. If you use the New button, a network alias is created, which is incorrect.
To change the properties of the logical device, select it from the list and click Edit. For example, the
nickname can be changed to a more descriptive name, such as eth0_office, so that it can be
recognized more easily.
In the list of devices, there is a column of checkboxes labeled Profile. For each profile, you can
check or uncheck devices. Only the checked devices are included for the currently selected profile.
For example, if you create a logical device named eth0_office in a profile called Office and
want to activate the logical device if the profile is selected, uncheck the eth0 device and check the
eth0_office device.
Figure 17.16, "Office Profile"
For example,
eth0_office. It is configured to activate the first Ethernet card using DHCP.
168
shows a profile called Office with the logical device
Section 17.11, "Device