Ubuntu 18.04: How to create a persistent dummy network interface
I am trying to create a dummy network interface on a Ubuntu 18.04 server. Here is how I would do it on my previous Ubuntu 16.04 servers:
In /etc/network/interfaces.d/dummy.cfg
, write:
auto dummy0
iface dummy0 inet static
address 192.168.98.1
netmask 255.255.255.0
And then add source /etc/network/interfaces.d/dummy.cfg
in /etc/network/interfaces/
From what I understand, Ubuntu 18.04 does not use /etc/network/interfaces
anymore, we should use netplan
instead. Apparently netplan
does not support the creation of virtual interface (!) https://bugs.launchpad.net/ubuntu/+source/nplan/+bug/1743200.
I can create the dummy interface with the iproute2 toolkit instead:
$ ip link add dummy0 type dummy
$ ip addr add 192.168.98.1/24 dev dummy0
$ ip link set dummy0 up
But this interface will disappear after reboot, as one would expect.
How can I create such a dummy network interface that will persist after reboot?
I had the same problem on 18.04 server and directly used the systemd-networkd way of configuring interfaces:
I created 2 files in /etc/systemd/network/
:
-
10-dummy0.netdev
[NetDev] Name=dummy0 Kind=dummy
-
20-dummy0.network
[Match] Name=dummy0 [Network] Address=192.168.... Address=fe80::.....
On boot the dummy interface is created automatically with IPv4 and IPv6 addresses an is shown in ip addr
. Also systemctl restart systemd-networkd
should create the interface.
I filed a bug on netplan, please support: https://bugs.launchpad.net/netplan/+bug/1774203
The docs:
https://www.freedesktop.org/software/systemd/man/systemd.netdev.html# https://www.freedesktop.org/software/systemd/man/systemd.link.html# https://www.freedesktop.org/software/systemd/man/systemd.network.html#