Comment 5 for bug 1727301

We have the same problem without bond configured. After upgrading to systemd 229-4ubuntu20 NOARP is set to our network interfaces. The machine has two network interfaces and the configuration is very simple:

# 50-ens5f0.network

[Match]
MACAddress=24:8a:7:11:50:a8

[Link]
MTUBytes=9000

[Network]
Address=10.32.34.34/30
DHCP=no
LinkLocalAddressing=no
IPv6AcceptRA=no

# 50-ens5f1.network
[Match]
MACAddress=24:8a:7:11:50:a9

[Link]
MTUBytes=9000

[Network]
Address=10.32.33.126/30
DHCP=no
LinkLocalAddressing=no
IPv6AcceptRA=no

# 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: ens5f0: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 24:8a:07:11:50:a8 brd ff:ff:ff:ff:ff:ff
3: ens5f1: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 24:8a:07:11:50:a9 brd ff:ff:ff:ff:ff:ff