I'm experiencing the same issue with OpenVPN Access Server + Duo Security. Our server requires both client certificate, username/password and a 2FA token.
The problem seems to be that network-manager-openvpn lacks support for username/password auth combined with challenge response. Expected scenario would be a second dialog asking for 2FA token, similar to what openvpn(1) does when started manually from the command line. May 6 11:12:38 hostname nm-openvpn[8558]: [OpenVPN Server] Peer Connection Initiated with [AF_INET]x.x.x.x:443 May 6 11:12:40 hostname nm-openvpn[8558]: AUTH: Received control message: AUTH_FAILED,CRV1:R,E:<removed>:Duo passcode or second factor: May 6 11:12:40 hostname NetworkManager[1032]: (nm-openvpn-service:8459): nm-openvpn-WARNING **: Password verification failed May 6 11:12:40 hostname nm-openvpn[8558]: SIGTERM[soft,auth-failure] received, process exiting May 6 11:12:40 hostname NetworkManager[1032]: <warn> VPN plugin failed: login-failed (0) % cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=15.04 DISTRIB_CODENAME=vivid DISTRIB_DESCRIPTION="Ubuntu 15.04" % dpkg -l | grep '^ii network-manager' ii network-manager 0.9.10.0-4ubuntu15.1 amd64 network management framework (daemon and userspace tools) ii network-manager-gnome 0.9.10.1-0ubuntu4 amd64 network management framework (GNOME frontend) ii network-manager-openvpn 0.9.10.0-1ubuntu1 amd64 network management framework (OpenVPN plugin core) ii network-manager-openvpn-gnome 0.9.10.0-1ubuntu1 amd64 network management framework (OpenVPN plugin GNOME GUI) ii network-manager-pptp 0.9.10.0-1ubuntu1 amd64 network management framework (PPTP plugin core) ii network-manager-pptp-gnome 0.9.10.0-1ubuntu1 amd64 network management framework (PPTP plugin GNOME GUI) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1322728 Title: VPN Connection Failed With 2 Factor Authentication To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager-openvpn/+bug/1322728/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs