Appendix A. Consistent Network Device Naming
Red Hat Enterprise Linux 6 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)|| || |
|PCI card network interface|| || |
|Virtual function|| || |
[a] New enumeration starts at
[b] For example:
[c] For example:
System administrators may continue to write rules in
/etc/udev/rules.d/70-persistent-net.rulesto change the device names to anything desired; those will take precedence over this physical location naming convention.
A.1. Affected Systems
Consistent network device naming is enabled by default for a set of
C Series, and
Precision Workstationsystems. For more details regarding the impact on Dell systems, visit https://access.redhat.com/kb/docs/DOC-47318.
For all other systems, it will be disabled by default; see Section A.2, “System Requirements” and Section A.3, “Enabling and Disabling the Feature” for more details.
Regardless of the type of system, Red Hat Enterprise Linux 6 guests running under Red Hat Enterprise Linux 5 hosts will not have devices renamed, since the virtual machine BIOS does not provide SMBIOS information. Upgrades from Red Hat Enterprise Linux 6.0 to Red Hat Enterprise Linux 6.1 are unaffected, and the old
eth[0123…]naming convention will continue to be used.