l2tp ipsec x509 vpn clients

i’ve got vyos 1.0.4 working with a l2tp ipsec vpn using x509 authentication.
i’ve got remote-access local-users configured with static addresses, for now, just username’s configured, no passwords.
authentication mode x509, with ca-cert-file (crt), server-cert-file (crt) and server-key-file (pem), no server-key-password

this configuration works, i can connect perfectly fine from windows,
all I needed to install were the ca certificate, and the client certificate (p12)

has anyone got a Ubuntu client working?
If so, how exactly did you do it? I keep finding conflicting instructions that never quite seem to match the configuration options.