From roughly systemd version 210, networking in my Droplet changed.

Out went netctl somehow (good riddance), and my network connectivity (uh oh).

Using Digital Ocean’s buggy Console Access, I managed to setup my network access manually.

/etc/network.d/ethernet-static gave me the previous network settings:

[root@sgd ~]# cat /etc/network.d/ethernet-static
CONNECTION='ethernet'
INTERFACE='eth0'
IP='static'
ADDR='128.199.252.174'
NETMASK='255.255.192.0'
GATEWAY='128.199.192.1'
DNS=('8.8.4.4' '8.8.8.8' '209.244.0.3')

How to setup a networking interface with ip

I’m more familiar with ifconfig & route, but with some frantic Googling I did figure out ip’s odd unfamilar API:

ip addr add 128.199.252.174/255.255.192.0 dev enp0s3
ip route add default via 128.199.192.1

ip a then looks like:

[root@sgd ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
	link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
	inet 127.0.0.1/8 scope host lo
	inet6 ::1/128 scope host
	   valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
	link/ether 04:01:11:8d:89:01 brd ff:ff:ff:ff:ff:ff
	inet 128.199.252.174/18 brd 128.199.255.255 scope global enp0s3
	inet6 fe80::601:11ff:fe8d:8901/64 scope link
	   valid_lft forever preferred_lft forever

Sidenote: I’m not sure why my Droplet’s network interface is called enp0s3 and not something simple like eth0.

Ping to test… YES… I can ssh in.

Now to migrate to systemd-networkd.

I created /etc/systemd/network/enp0s3.network:

[root@sgd ~]# cat /etc/systemd/network/enp0s3.network
# Migrated from /etc/network.d/ethernet-static
# https://coreos.com/blog/intro-to-systemd-networkd/
[Match]
Name=enp0s3
[Network]
Address=128.199.252.174/18
Gateway=128.199.192.1

1. To test systemctl start systemd-networkd.service.

• Check systemctl status systemd-networkd.service looks good

    [root@sgd ~]# systemctl status systemd-networkd.service
    systemd-networkd.service - Network Service
       Loaded: loaded (/usr/lib/systemd/system/systemd-networkd.service; enabled)
       Active: active (running) since Thu 2014-03-13 04:02:24 UTC; 11min ago
    	 Docs: man:systemd-networkd.service(8)
     Main PID: 158 (systemd-network)
       Status: "Processing requests..."
       CGroup: /system.slice/systemd-networkd.service
    		   `-158 /usr/lib/systemd/systemd-networkd
    Mar 13 04:02:24 sgd systemd-networkd[158]: enp0s3: link is up
    Mar 13 04:02:24 sgd systemd-networkd[158]: enp0s3: carrier on
    Mar 13 04:02:24 sgd systemd-networkd[158]: enp0s3: link configured
    Mar 13 04:02:24 sgd systemd[1]: Started Network Service.
  

To watch/tail what the systemd-networkd.service is doing, journalctl -u systemd-networkd.service -f

• Enable it systemctl enable systemd-networkd.service
• And reboot!

Loose ends, ifplugd

I noticed in htop ifplugd is running. I can’t see from systemctl or pstree what invoked it. Mysterious.

[root@sgd ~]# ps aux | grep ifplugd
root       136  0.0  0.0   2200   284 ?        Ss   04:02   0:00 /usr/bin/ifplugd -i enp0p3 -r /etc/ifplugd/netcfg.action -fIns
root     27388  0.0  0.1   2828   584 pts/1    S+   04:16   0:00 grep ifplugd