Sounds like this is a bug in systemd, since it's what will deal with the actual devices.
** Also affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1746419 Title: bond parameters are not changed by 'netplan apply' Status in nplan package in Ubuntu: New Status in systemd package in Ubuntu: New Bug description: I have a yaml file as follows: network: version: 2 ethernets: bonddevs: match: name: ens bonds: bond0: interfaces: [bonddevs] parameters: mode: active-backup mii-monitor-interval: 1 addresses: - 10.10.10.1/24 Say I decide that 1s is too frequent for the MII interval, and I want to change the interval to 2s. If I change that in the yaml, then run # netplan generate # netplan apply # cat /proc/net/bonding/bond0|grep "MII Polling Interval (ms)" MII Polling Interval (ms): 1000 In other words, the change has not been applied. Running netplan --debug apply prints: DEBUG:device bond0 operstate is up, not replugging So I wondered if bringing the bond down would help. It does not: # ip link set dev bond0 down # netplan apply # cat /proc/net/bonding/bond0|grep "MII Polling Interval (ms)" MII Polling Interval (ms): 1000 However, deleting the link works: # ip link del dev bond0 # netplan apply # cat /proc/net/bonding/bond0|grep "MII Polling Interval (ms)" MII Polling Interval (ms): 2000 This is counter-intuitive behaviour. Ideally, I would like a regular netplan apply to work without deleting the bond. However, a changed to the docs to make this clear would be OK. ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: nplan 0.32~17.10.1 ProcVersionSignature: User Name 4.13.0-32.35-generic 4.13.13 Uname: Linux 4.13.0-32-generic x86_64 ApportVersion: 2.20.7-0ubuntu3.7 Architecture: amd64 Date: Wed Jan 31 05:47:42 2018 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=C.UTF-8 SHELL=/bin/bash SourcePackage: nplan UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nplan/+bug/1746419/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : email@example.com Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp