Consistent Network Device Naming
Fedora 17 provides consistent network device naming for network interfaces. This feature changes the name of network interfaces on a system in order to make locating and differentiating the interfaces easier.
Traditionally, network interfaces in Linux are enumerated as
eth[0123…]
, but these names do not necessarily correspond to actual labels on the chassis. Modern server platforms with multiple network adapters can encounter non-deterministic and counter-intuitive naming of these interfaces. This affects both network adapters embedded on the motherboard (
Lan-on-Motherboard, or
LOM) and add-in (single and multiport) adapters.
The new naming convention assigns names to network interfaces based on their physical location, whether embedded or in PCI slots. By converting to this naming convention, system administrators will no longer have to guess at the physical location of a network port, or modify each system to rename them into some consistent order.
This feature, implemented via the
biosdevname program, will change the name of all embedded network interfaces, PCI card network interfaces, and virtual function network interfaces from the existing
eth[0123…]
to the new naming convention as shown in
Table A.1, “The new naming convention”.
Table A.1. The new naming convention
Device
|
Old Name
|
New Name
|
---|
Embedded network interface (LOM)
|
eth[0123…]
|
em[1234…] []
|
PCI card network interface
|
eth[0123…]
|
p<slot >p<ethernet port > []
|
Virtual function
|
eth[0123…]
|
p<slot >p<ethernet port >_<virtual interface > []
|
System administrators may continue to write rules in /etc/udev/rules.d/70-persistent-net.rules
to change the device names to anything desired; those will take precedence over this physical location naming convention.
Regardless of the type of system, Fedora guests will not have devices renamed unless the virtual machine BIOS provides the SMBIOS information outlined in
Section A.2, “System Requirements”. Also, upgrades from prior releases that did not use this naming convention (that is, Fedora 14 and older) are unaffected, and the old naming convention will continue to be used.