Novell LINUX ENTERPRISE SERVER 10 - INSTALLATION AND ADMINISTRATION 04-08-2006 Installation Manual page 601

To assign a certain network configuration to any card of a certain type (of which only
one is inserted at a time) instead of a certain card, select less specific configuration
names. For example, bus-pcmcia would be used for all PCMCIA cards. On the
other hand, the names can be limited by a preceding interface type. For example,
wlan-bus-usb would be assigned to WLAN cards connected to a USB port.
The system always uses the configuration that best describes an interface or the device
providing the interface. The search for the most suitable configuration is handled by
getcfg. The output of getcfg delivers all information that can be used for describing
a device. Details regarding the specification of configuration names are available in the
manual page of getcfg.
With the described method, a network interface is configured with the correct configu-
ration even if the network devices are not always initialized in the same order. However,
the name of the interface still depends on the initialization sequence. There are two
ways to ensure reliable access to the interface of a certain network card:
• getcfg-interface configuration name returns the name of the asso-
ciated network interface. Therefore, the configuration name, such as firewall, dhcpd,
routing, or various virtual network interfaces (tunnels), can be entered in some
configuration files instead of the interface name, which is not persistent.
• Persistent interface names are assigned to each interface automatically. You may
adjust them to suit your needs. When creating interface names, proceed as outlined
in /etc/udev/rules.d/30-net_persistent_names.rules. However,
the persistent name pname should not be the same as the name that would automat-
ically be assigned by the kernel. Therefore, eth*, tr*, wlan*, qeth*, iucv*,
and so on are not permitted. Instead, use net* or descriptive names like
external, internal, or dmz. Make sure that the same interface name is not
used twice. Allowed characters in interface names are restricted to [a-zA-Z0-9].
A persistent name can only be assigned to an interface immediately after its regis-
tration, which means that the driver of the network card must be reloaded or
hwup device description must be executed. The command rcnetwork
restart is not sufficient for this purpose.
IMPORTANT: Using Persistent Interface Names
The use of persistent interface names has not been tested in all areas.
Therefore, some applications may not be able to handle freely selected
interface names.
Basic Networking 601