Comment 0 for bug 1799487

Like many I use tunnelbroker.net for IPv6 connectivity on servers that lack native IPv6 connectivity through their provider.

Back in ifupdown, this was done with a nice and short snippet that looked like this:
```
auto he-ipv6
iface he-ipv6 inet6 v4tunnel
    address 2001:470:1c:1d7::2
    netmask 64
    endpoint 216.66.38.58
    local 192.222.186.156
    mtu 1480
    ttl 64
```

There is however no equivalent in netplan that I could find (on 18.04 at least), instead I had to do the following to get networkd to setup the tunnel.

1) Define a netdev (/etc/systemd/network/he-ipv6.netdev)
```
[NetDev]
Name=he-ipv6
Kind=sit
MTUBytes=1480

[Tunnel]
Local=54.39.107.213
Remote=216.66.38.58
TTL=64
```

2) Define a network (/etc/systemd/network/he-ipv6.network)
```
[Match]
Name=he-ipv6

[Network]
Address=2001:470:1c:b62::2/64
Gateway=2001:470:1c:b62::1
```

3) Setup a dependency between my WAN interface and the tunnel (/etc/systemd/network/10-netplan-eth0.network.d/tunnel.conf)
```
[Network]
Tunnel=he-ipv6
```

This then all works fine but has the very annoying side-effect of splitting my network config into a bunch of different pieces with everything in my netplan.yaml except for that tunnel which I have to configure directly in networkd and use systemd unit overrides to add the needed Tunnel statement to the netplan managed wan interface.