Operation Manual

When the Kernel detects a network card and creates a corresponding network interface,
it assigns the device a name depending on the order of device discovery, or order of
the loading of the Kernel modules. The default Kernel device names are only predictable
in very simple or tightly controlled hardware environments. Systems which allow adding
or removing hardware during runtime or support automatic conguration of devices
cannot expect stable network device names assigned by the Kernel across reboots.
However, all system conguration tools rely on persistent interface names. This problem
is solved by udev. The udev persistent net generator (/lib/udev/rules.d/75
-persistent-net-generator.rules) generates a rule matching the hardware
(using its hardware address by default) and assigns a persistently unique interface for
the hardware. The udev database of network interfaces is stored in the le /etc/
udev/rules.d/70-persistent-net.rules. Every line in the le describes
one network interface and species its persistent name. System administrators can
change the assigned names by editing the NAME="" entries. The persistent rules can
also be modied using YaST.
Table 23.6, “Manual Network Conguration Scripts” (page 398) summarizes the most
important scripts involved in the network conguration.
Table 23.6
Manual Network Conguration Scripts
FunctionCommand
The if scripts start or stop network interfaces, or return the status
of the specied interface. For more information, see the ifup
manual page.
ifup,
ifdown,
ifstatus
The rcnetwork script can be used to start, stop or restart all
network interfaces (or just a specied one). Use rcnetwork
rcnetwork
stop to stop, rcnetwork start to start and rcnetwork
restart to restart network interfaces. If you want to stop, start
or restart just one interface, use the command followed by the in-
terface name, for example rcnetwork restart eth0. The
rcnetwork status command displays the state of the inter-
faces, their IP addresses and whether a DHCP client is running.
With rcnetwork stop-all-dhcp-clients and
398 Reference