Proposed F19 Feature: systemd/udev Predictable Network Interface Names
jreznik at redhat.com
Wed Jan 23 19:59:07 UTC 2013
= Features/SystemdPredictableNetworkInterfaceNames =
Feature owner(s): Kay Sievers <kay at redhat dot com>
The udevd service has a long history of providing predicatable names for block
devices and others. For Fedora 19 we'd like to provide the same for network
interfaces, following a similar naming scheme, but only as fallback if not
other solution such as biosdevname is installed or the administrator manually
defined network interface names via udev rules or the old network scripts.
== Detailed description ==
The classic naming scheme for network interfaces applied by the kernel is to
simply assign names beginning with "eth0", "eth1", ... to all interfaces as
they are probed by the drivers. As the driver probing is generally not
predictable for modern technology this means that as soon as multiple network
interfaces are available the assignment of the names "eth0", "eth1" and so on
is generally not fixed anymore and it might very well happen that "eth0" on one
boot ends up being "eth1" on the next. This can have serious security
implications, for example in firewall rules which are coded for certain naming
schemes, and which are hence very sensitive to unpredictable changing names.
Starting with v197 systemd/udev can automatically assign predictable, stable
network interface names for all local Ethernet, WLAN and WWAN interfaces. This
is a departure from the traditional interface naming scheme ("eth0", "eth1",
"wlan0", ...), but should fix real problems.
This feature is about enabling this as default in Fedora, but only as a
fallback if the user/administrator did not manually assign names to interfaces
via udev rules, or via the old networking scripts, or if biosdevname is
For a longer discussion about this feature see the upstream documentation.
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