allowedIPs should be 0.0.0.0/0 and it should just work
Discussion
On the remote side side you may need
iptables -t nat -A POSTROUTING -s 10.100.0.0/24 -o eth0 -j MASQUERADE
allowedIPs should be 0.0.0.0/0 and it should just work
On the remote side side you may need
iptables -t nat -A POSTROUTING -s 10.100.0.0/24 -o eth0 -j MASQUERADE