Bug 118111

Summary: rc: network.subr Add MAC address based interface renaming
Product: Base System Reporter: Thomas Hurst <tom>
Component: confAssignee: Kyle Evans <kevans>
Status: Open ---    
Severity: Affects Some People CC: eborisch+FreeBSD, emaste, freebsd, kevans, koobs, lifanov, ltning-freebsd, net, olivierw1+bugzilla-freebsd, pi, portmaster, shurd, sm, travis, vermaden
Priority: Normal Keywords: easy, feature, needs-qa
Version: CURRENTFlags: koobs: maintainer-feedback? (net)
koobs: mfc-stable12?
koobs: mfc-stable11?
Hardware: Any   
OS: Any   
See Also: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=212480
Attachments:
Description Flags
file.diff
none
file.diff
none
Patch against CURRENT none

Description Thomas Hurst 2007-11-18 23:00:04 UTC
I recently temporarily added an additional network card to my system for
testing, thus moving all my interface names about; em0 becomes em1, etc,
necessitating annoying configuration changes and/or cable juggling.

Many Linux distributions solve this problem with /etc/iftab or /etc/mactab,
wiring an interface name to a MAC address so they're no longer dependent on
probe order.

This patch adds similar functionality to network.subr's ifnet_rename function,
so things like the following can be added to rc.conf:

ifconfig_mac_names="lan0 inet0"
ifconfig_mac_lan0="00:04:23:c4:68:a8"
ifconfig_mac_inet0="00:04:23:c4:68:ab"

Also included is a small patch against the rc.conf(5) manpage.

Both patches are against RELENG_7, but should apply relatively cleanly against
RELENG_6.
Comment 1 OlivierW 2016-12-18 23:23:52 UTC
Hello,

It would be nice to have this patch merged as I think it's quite useful :-)

Best Regards
Comment 2 Thomas Hurst 2018-07-13 23:37:54 UTC
Created attachment 195121 [details]
Patch against CURRENT

Since this hasn't had much love lately, I've done a bit of work to update the network.subr patch against CURRENT so at least there's something new to look at.

This patch changes how it works a little - the original example now looks like this:

ifconfig_ether_00_04_23_c4_68_a8_name="lan0"
ifconfig_ether_00_04_23_c4_68_ab_name="inet0"

Not quite as pretty, but the patch is a fair bit simpler now.

Renaming is still pretty rudimentary - it can't reliably pin, say, "em0", because another interface may already have that name, but one step at a time.

Care also needs to be taken if a system is sharing "ether" across multiple interfaces, e.g. with lagg.  hwaddr might be more appropriate in these cases, and this naming scheme helpfully leaves room for that in future.
Comment 3 Kubilay Kocak freebsd_committer freebsd_triage 2019-05-21 03:59:40 UTC
Can't be in progress without an assignee
Comment 4 Chris Hutchinson 2020-10-29 16:24:56 UTC
I have/use several multi-port NIC's where something like this
would be wonderful to have available. It's now been more than
a decade. Any chance we can get this committed before 2030?

A big thanks to everyone involved -- especially Thomas. :-)
Comment 5 Slawomir Wojciech Wojtczak 2020-10-30 18:12:50 UTC
> Any chance we can get this committed before 2030?

Loved that one. Made my day :)
Comment 6 eborisch+FreeBSD 2021-07-13 14:56:51 UTC
The https://www.freshports.org/sysutils/ethname port is available that performs essentially the same function while waiting for 2030. ;)

Required entries in rc.conf:

ethname_enable="YES"
ethname_foo_mac="aa:bb:cc:dd:ee:ff"
Comment 7 Santiago Martinez 2021-09-05 23:49:56 UTC
What needs to be done to get this merged? 

If testing is required I can do some.
Comment 8 Slawomir Wojciech Wojtczak 2021-09-06 08:06:38 UTC
One question, has it been tested with lagg(4) interfaces?

Not sure on FreeBSD but on Linux when I had bond0 interface and the scripts 'per interface' had MAC address then they failed because after bond0 was activated/created the network interfaces had MAC addresses changed.

Regards.