Operation Manual
21.6 Conguring a Network
Connection Manually
Manual conguration of the network software should always be the last alternative.
Using YaST is recommended. However, this background information about the network
conguration can also assist your work with YaST.
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 conguration of devices
cannot expect stable network device names assigned by the kernel across reboots.
However, all system conguration tools rely on persistent interface names. The 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 species its persistent name. System administrators can
change the assigned names by editing the NAME="" entries. The persistent rules can
also be modied using YaST.
Table 21.5, “Manual Network Conguration Scripts” (page 351) summarizes the most
important scripts involved in the network conguration.
Table 21.5
Manual Network Conguration Scripts
FunctionCommand
The if scripts start or stop network interfaces, or return the status
of the specied 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 specied one). Use rcnetwork
rcnetwork
Basic Networking 351