Biosdevname

Biosdevname is a Linux user-space utility and accompanying udev rules that provide stable, BIOS-derived names for network interfaces. It derives an interface’s name from firmware and PCI information, producing labels such as em1 or eth0 that reflect the device’s hardware location rather than the kernel’s arbitrary enumeration. This makes network configuration more predictable across reboots and hardware changes, which is especially important on servers and automated deployments.

Typically shipped on Red Hat–based distributions, biosdevname runs during early boot to assign names before the interface is brought up. It relies on a policy that maps PCI bus position, device type, and firmware identity to a particular name, and it can be configured to prefer or override certain schemes. The resulting naming is implemented through udev so that all subsequent network configuration refers to the consistent label.

With the introduction of predictable network interface names by systemd and other libudev components, the use of biosdevname has declined in newer systems. Some distributions still provide biosdevname for compatibility with legacy scripts or to support specific hardware naming conventions, and the package may be retained for environments that require BIOS-based names.

Configuration and management: Administrators can enable or disable biosdevname and adjust its naming policy via configuration files or kernel parameters. In practice, it interacts with the boot process and udev to apply names consistently, while remaining compatible with legacy network configuration tools. See also udev, predictable network interface names, and Red Hat networking documentation.