No documented way to set the MAC for a bridge or bond

[Mike Pontillo]

According to the current documentation[1], there is no way to set the MAC address for a bridge or bond interface. This is requirement for the MAAS use case.

Tentatively, I'm writing rendering the netplan with a 'macaddress' key under each bond or bridge (since that seems the most consistent with the `match` syntax).

[1]:
https://git.launchpad.net/netplan/tree/doc/netplan.md

[Ryan Harper (raharper)]

For networkd, All virtual net devices support general parameters, including MACAddress
and this works as expected if netplan passes through macaddress parameters to netdevs it creates.

root@z1:/etc/systemd/network# cat br0.net*
[NetDev]
Name=br0
MACAddress=00:11:22:33:44:55
Kind=bridge
[Match]
Name=br0

[Network]
Address=192.168.2.1/24

root@z1:/etc/systemd/network# networkctl
IDX LINK TYPE OPERATIONAL SETUP
  1 lo loopback carrier unmanaged
  2 br0 ether no-carrier configuring
 16 eth0 ether routable unmanaged

3 links listed.
root@z1:/etc/systemd/network# ifconfig br0
br0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
        inet 192.168.2.1 netmask 255.255.255.0 broadcast 192.168.2.255
        ether 00:11:22:33:44:55 txqueuelen 1000 (Ethernet)
        RX packets 0 bytes 0 (0.0 B)
        RX errors 0 dropped 0 overruns 0 frame 0
        TX packets 0 bytes 0 (0.0 B)
        TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

root@z1:/etc/systemd/network# cat *bond*
[NetDev]
Name=bond0
MACAddress=aa:bb:cc:00:11:22
Kind=bond
Mode=balance-rr
[Match]
Name=bond0

[Network]
Address=10.2.71.1/24
root@z1:/etc/systemd/network# ifconfig bond0
bond0: flags=5123<UP,BROADCAST,MASTER,MULTICAST> mtu 1500
        inet 10.2.71.1 netmask 255.255.255.0 broadcast 10.2.71.255
        ether aa:bb:cc:00:11:22 txqueuelen 1000 (Ethernet)
        RX packets 0 bytes 0 (0.0 B)
        RX errors 0 dropped 0 overruns 0 frame 0
        TX packets 0 bytes 0 (0.0 B)
        TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

[Mathieu Trudel-Lapierre (cyphermox)]

Right, this appears well supported by networkd, but not at all by NetworkManager. I'll file a bug upstream about this.

[Mike Pontillo (mpontillo)]

Adding MAAS; we need to ensure MAAS is generating the expected Netplan once this has been defined.

[Mathieu Trudel-Lapierre (cyphermox)]

This is complicated, it appears as though networkd and NetworkManager don't always get the MAC change even if we force re-applying the .link file via udevadm. This will need more work.

[Mike Pontillo (mpontillo)]

Curious what you mean by 're-applying'. Are you syaing it generates the correct configuration the first time, but it cannot subsequently be updated?

[Mathieu Trudel-Lapierre (cyphermox)]

The configuration is correctly generated, but requires a reboot. Simply trying to apply the new cloned MAC even with net_setup_link does not appear to work.

[Mathieu Trudel-Lapierre (cyphermox)]

I'm marking this a duplicate of bug 1690388: it already contains the cloud-init bits and milestones for SRU; and a bit more information about the issue at hand.