The Dream Machine Pro is a very capable machine but it being in the SMB space makes it difficult to work with at times; especially figuring out why VPN doesn’t work because it doesn’t expose any of the logs through the UI.
To be able to look at the details of the configuration, SSH must be enabled. The username name is “root” and the password is set under System. I haven’t quite figured out what the Network level SSH credentials are for. The following are useful commands to troubleshoot VPN:
# ipsec statusall
# ipsec restart
# strongctl --log