Dummy interface to share resources

Objective

The goal of the dummy interface is to bind services to it instead of local host. Bound services will be available from other resources on the host; such as container or VM.

Configuration

The creation and the configuration of the dummy interface can be accomplished with systemd-networkd.

Start by creating the dummy interface, which we'll call jump0.

# /etc/systemd/networkd/jumpbox.netdev
[NetDev]
Name=jump0
Kind=dummy

Then, configure and IP address and disable IPv6 link-local.

# /etc/systemd/networkd/jumpbox.network
[Match]
Name=jump0

[Address]
DHCP=none
Address=192.0.2.250/30

[Network]
LinkLocalAddressing=ipv4

The most common way that I use this interface is when I'm local fowarding ports with ssh.

# ~/.ssh/config
host jump
    hostname HOST
    port PORT
    User USER
    LocalForward 192.0.2.250:LOCAL_PORT REMOTE_IP:REMOTE_PORT
    SessionType none