Espressobin network configuration?

Hi,

With a downloaded and installed Armbian Ubuntu 16.04.5 LTS image things seem to work as expected: lan0 and lan1 act like they are ports on an ordinary ethernet switch. My LAN is connected to lan0 and a device (HDHomeRun) is connected to lan1. The device and the Espressobin are accessible from other computers on the LAN and the Espressobin can access everything on my LAN (and beyond).

But, digging deeper, something isn't quite right. The DHCP server on my LAN has been configured to assign a fixed IP address to br0 and the DHCP client for br0 on the Espressobin should be activated by /etc/systemd/network/10-br0.network: 

ebin@espressobin:~$ cat /etc/systemd/network/10-br0.network
[Match]
Name=br0

[Network]
DHCP=ipv4

That seems to work as expected.

lan0 and lan1 are a different matter. Just as for an ethernet switch, I would expect (as members of a bridge) neither to be assigned an IP address.

ebin@espressobin:~$ cat /etc/systemd/network/10-lan.network 
[Match]
Name=lan*

[Network]
Bridge=br0

ebin@espressobin:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: bond0: <NO-CARRIER,BROADCAST,MULTICAST,MASTER,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether b6:0e:66:f8:d3:a8 brd ff:ff:ff:ff:ff:ff
3: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether 4a:ab:78:59:41:5f brd ff:ff:ff:ff:ff:ff
    inet6 fe80::48ab:78ff:fe59:415f/64 scope link 
       valid_lft forever preferred_lft forever
4: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 532
    link/ether 00:50:43:84:fb:2f brd ff:ff:ff:ff:ff:ff
    inet6 fe80::250:43ff:fe84:fb2f/64 scope link 
       valid_lft forever preferred_lft forever
5: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 9a:b7:48:8e:77:24 brd ff:ff:ff:ff:ff:ff
    inet 10.137.113.131/24 brd 10.137.113.255 scope global br0
       valid_lft forever preferred_lft forever
    inet6 fe80::98b7:48ff:fe8e:7724/64 scope link 
       valid_lft forever preferred_lft forever
6: wan@eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue master br0 switchid 00000000 state LOWERLAYERDOWN group default qlen 1000
    link/ether 00:50:43:84:fb:2f brd ff:ff:ff:ff:ff:ff
7: lan0@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br0 switchid 00000000 state UP group default qlen 1000
    link/ether 00:50:43:84:fb:2f brd ff:ff:ff:ff:ff:ff
    inet 10.137.113.11/24 brd 10.137.113.255 scope global lan0
       valid_lft forever preferred_lft forever
8: lan1@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br0 switchid 00000000 state UP group default qlen 1000
    link/ether 00:50:43:84:fb:2f brd ff:ff:ff:ff:ff:ff

For some reason lan0 gets an IP address, but lan1 doesn't. What's more, a DHCPDISCOVER is being sent out by the Espressobin every 10-15 seconds.

What's going on here?

pygr