the networking is configured via systemd-networkd. bonding module is loaded with 'max_bonds=0' to address upcoming systemd change https://github.com/systemd/systemd/issues/6184 pre-upgrade: # networkctl IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether carrier configuring 3 eth1 ether carrier configuring 4 bond0 ether routable configured 5 bond0.200 ether routable configured # ip link 1: lo: mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eth0: mtu 9000 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff 3: eth1: mtu 9000 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff 4: bond0: mtu 9000 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff 5: bond0.200@bond0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff interfaces(.d) and netplan are empty and unused/disabled /etc/systemd/network: # cat eth1.network [Match] Name=eth1 [Network] Bond=bond0 # cat eth0.network [Match] Name=eth0 [Network] Bond=bond0 # cat bond0.netdev [NetDev] Name=bond0 Kind=bond [Bond] Mode=802.3ad MIIMonitorSec=0.1s LACPTransmitRate=fast UpDelaySec=0.2s DownDelaySec=0.2s # cat bond0.network [Match] Name=bond0 [Address] Address=192.168.1.100/24 [Route] Gateway=192.168.1.1 [Network] VLAN=bond0.200 [Link] MTUBytes=9000 # cat bond0.200.netdev [NetDev] Name=bond0.200 Kind=vlan [VLAN] Id=200 # cat bond0.200.network [Match] Name=bond0.200 [Address] Address=10.10.0.100/16 [Route] Gateway=10.10.0.1 [Link] MTUBytes=9000 After upgrade: # networkctl IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether carrier configuring 3 eth1 ether carrier configuring 4 bond0 ether routable configured 5 bond0.200 ether routable configured However, the link of eth0, eth1 and the bond and vlan interface changes to NOARP # ip link 1: lo: mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eth0: mtu 9000 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff 3: eth1: mtu 9000 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff 4: bond0: mtu 9000 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff 5: bond0.200@bond0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 5a:42:ff:c5:26:61 brd ff:ff:ff:ff:ff:ff