Hey again,

I'll update the demo.wireguard.com scripts in the repo in a bit to
make them slightly more simple and support v6, like the attached, but
thought you might benefit from this now.

zx2c4@thinkpad ~ $ ./client.sh > /etc/wireguard/demo.conf
zx2c4@thinkpad ~ $ wg-quick up demo
[#] ip link add demo type wireguard
[#] wg setconf demo /dev/fd/63
[#] ip address add 192.168.4.178/32 dev demo
[#] ip link set mtu 1420 dev demo
[#] ip link set demo up
[#] resolvconf -a tun.demo -m 0 -x
[#] wg set x fwmark 51820
[#] ip -4 route add 0.0.0.0/0 dev demo table 51820
[#] ip -4 rule add not fwmark 51820 table 51820
[#] ip -4 rule add table main suppress_prefixlength 0
zx2c4@thinkpad ~ $ curl -4 zx2c4.com/ip
163.172.161.0
demo.wireguard.com
curl/7.56.1

Please don't run the script more than once or twice or thrice.

Jason