Published: Thursday, Mar 13, 2014 Last modified: Monday, Oct 26, 2020

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.

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

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