8.6. Consistent Network Device Naming Using biosdevname

This feature, implemented through the biosdevname udev helper utility, 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 8.2, “The biosdevname Naming Convention”. Note that unless the system is a Dell system, or biosdevname is explicitly enabled as described in Section 8.6.2, “Enabling and Disabling the Feature”, the systemd naming scheme will take precedence.

Table 8.2. The biosdevname Naming Convention

Device Old Name New Name
Embedded network interface (LOM) eth[0123…] em[1234…][a]
PCI card network interface eth[0123…] p<slot>p<ethernet port>[b]
Virtual function eth[0123…] p<slot>p<ethernet port>_<virtual interface>[c]
[a] New enumeration starts at 1.
[b] For example: p3p4
[c] For example: p3p4_1

8.6.1. System Requirements

The biosdevname program uses information from the system's BIOS, specifically the type 9 (System Slot) and type 41 (Onboard Devices Extended Information) fields contained within the SMBIOS. If the system's BIOS does not have SMBIOS version 2.6 or higher and this data, the new naming convention will not be used. Most older hardware does not support this feature because of a lack of BIOSes with the correct SMBIOS version and field information. For BIOS or SMBIOS version information, contact your hardware vendor.
For this feature to take effect, the biosdevname package must also be installed. To install it, issue the following command as root:
~]# yum install biosdevname

8.6.2. Enabling and Disabling the Feature

To disable this feature, pass the following option on the boot command line, both during and after installation:
biosdevname=0
To enable this feature, pass the following option on the boot command line, both during and after installation:
biosdevname=1
Unless the system meets the minimum requirements, this option will be ignored and the system will use the systemd naming scheme as described in the beginning of the chapter.
If the biosdevname install option is specified, it must remain as a boot option for the lifetime of the system.