Comment 8 for bug 1727301

I have packages built with above patch applied, which I suspect is the missing portion to fix this.
It is available from this ppa https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/3015
$ sudo add-apt-repository ppa:ci-train-ppa-service/3015
$ sudo apt-get update

I am failing to reproduce the reported regression, with quite similar setup. (See below).

Am I missing some sysctls to reproduce the regression? Or are my bonds/vlans/ethernet not suitable to trigger this regression?

# ip link
1: lo: <LOOPBACK,UP,LOWER_UP> 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: enp3s0f0: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000
    link/ether 4a:fd:00:df:13:a3 brd ff:ff:ff:ff:ff:ff
3: enp3s0f1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000
    link/ether 4a:fd:00:df:13:a3 brd ff:ff:ff:ff:ff:ff
4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 4a:fd:00:df:13:a3 brd ff:ff:ff:ff:ff:ff
5: bond0.204@bond0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether bc:76:4e:20:69:4c brd ff:ff:ff:ff:ff:ff
6: bond0.104@bond0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether bc:76:4e:20:68:3d brd ff:ff:ff:ff:ff:ff

# dpkg -l | grep 229-4ubuntu20
ii libpam-systemd:amd64 229-4ubuntu20 amd64 system and service manager - PAM module
ii libsystemd0:amd64 229-4ubuntu20 amd64 systemd utility library
ii libudev1:amd64 229-4ubuntu20 amd64 libudev shared library
ii systemd 229-4ubuntu20 amd64 system and service manager
ii systemd-sysv 229-4ubuntu20 amd64 system and service manager - SysV links
ii udev 229-4ubuntu20 amd64 /dev/ and hotplug management daemon

==> 10-netplan-bond0.104.netdev <==
[NetDev]
Name=bond0.104
MACAddress=bc:76:4e:20:68:3d
Kind=vlan

[VLAN]
Id=104

==> 10-netplan-bond0.104.network <==
[Match]
Name=bond0.104

[Network]
Address=172.99.85.226/30
Address=2001:4802:78fd:33:be76:4eff:fe20:683d/64

[Route]
Destination=0.0.0.0/0
Gateway=172.99.85.225

[Route]
Destination=::/0
Gateway=2001:4802:78fd:33::1

==> 10-netplan-bond0.204.netdev <==
[NetDev]
Name=bond0.204
MACAddress=bc:76:4e:20:69:4c
Kind=vlan

[VLAN]
Id=204

==> 10-netplan-bond0.204.network <==
[Match]
Name=bond0.204

[Network]
Address=10.184.228.158/30

[Route]
Destination=10.176.0.0/12
Gateway=10.184.228.157

[Route]
Destination=10.208.0.0/12
Gateway=10.184.228.157

==> 10-netplan-bond0.netdev <==
[NetDev]
Name=bond0
Kind=bond

[Bond]
Mode=802.3ad
MIIMonitorSec=100
TransmitHashPolicy=layer3+4

==> 10-netplan-bond0.network <==
[Match]
Name=bond0

[Network]
VLAN=bond0.204
VLAN=bond0.104

==> 10-netplan-enp3s0f0.link <==
[Match]
MACAddress=58:20:b1:00:b8:4c

[Link]
Name=enp3s0f0
WakeOnLan=off
MTUBytes=1500

==> 10-netplan-enp3s0f0.network <==
[Match]
MACAddress=58:20:b1:00:b8:4c
Name=enp3s0f0

[Network]
DNS=69.20.0.196
DNS=69.20.0.164
Bond=bond0
LinkLocalAddressing=no
IPv6AcceptRA=no

==> 10-netplan-enp3s0f1.link <==
[Match]
MACAddress=58:20:b1:00:b8:4d

[Link]
Name=enp3s0f1
WakeOnLan=off
MTUBytes=1500

==> 10-netplan-enp3s0f1.network <==
[Match]
MACAddress=58:20:b1:00:b8:4d
Name=enp3s0f1

[Network]
DNS=69.20.0.196
DNS=69.20.0.164
Bond=bond0
LinkLocalAddressing=no
IPv6AcceptRA=no