Proposed F19 Feature: systemd/udev Predictable Network Interface Names

[Bradley Baetz]

On 07/02/13 00:33, Michal Schmidt wrote:
> On 02/05/2013 02:53 AM, Scott Schmit wrote:
>>  Is there a program/script we can run that would tell us what the
>> interface names would be without biosdevname (without running the new
>> version of systemd on the box)?
>
> If you have Fedora 18 with updates applied your systemd is new enough to
> allow you to see the udev-generated names using:
>
> udevadm info --export -p /sys/class/net/$IFACE | grep ID_NET
>
> Example output:
>
> E: ID_NET_NAME_MAC=enx000f53014229
> E: ID_NET_NAME_PATH=enp40s0f1d1
> E: ID_NET_NAME_SLOT=ens4f1d1

What happens with USB network devices that are plugged into different 
slots? Currently my iPhone shows up as eth1, but using the above, 
depending on which of two adjacent ports I happen to plug it into, I get:

$ udevadm info --export -p /sys/class/net/eth1 | grep ID_NET
E: ID_NET_NAME_MAC=enx0226b08178a9
E: ID_NET_NAME_PATH=enp0s29f7u1c4i2

$ udevadm info --export -p /sys/class/net/eth1 | grep ID_NET
E: ID_NET_NAME_MAC=enx0226b08178a9
E: ID_NET_NAME_PATH=enp0s29f7u2c4i2

Will those be treated as two separate devices under this scheme 
depending on which USB port I happen to use? And if so, will that 
actually matter?

Bradley