I am trying to connect to a VPN using l2tp ipsec from ubuntu 18.04.   After a bit of trying i've managed to get   PAP authentication succeeded   but im now getting the following error   Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2375] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",0]: VPN connection: (IP4 Config Get) reply received from old-style plugin Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2394] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: VPN Gateway: IP Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2395] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Tunnel Device: "ppp0" Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2396] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: IPv4 configuration: Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2396] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Internal Address: 192.168.30.39 Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2397] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Internal Prefix: 32 Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2397] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Internal Point-to-Point Address: 10.0.0.1 Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2398] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Static Route: 0.0.0.0/0 Next Hop: 0.0.0.0 Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2399] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Static Route: 10.0.0.1/32 Next Hop: 0.0.0.0 Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2399] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Internal DNS: <IP Removed> Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2400] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: Internal DNS: <IP Removed> Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2401] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: DNS Domain: '(none)' Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2401] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: Data: No IPv6 configuration Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2405] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: VPN plugin: state changed: started (4) Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2478] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: VPN connection: (IP Config Get) complete Oct 29 15:06:26 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:26 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.2485] device (ppp0): state change: unavailable -> disconnected (reason 'none', sys-iface-state: 'external') Oct 29 15:06:26 localhost dbus-daemon[989]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' requested by ':1.161' (uid=0 pid=14390 comm="/usr/sbin/NetworkManager --no-daemon ") Oct 29 15:06:26 localhost nm-applet[2826]: Can't set a parent on widget which has a parent Oct 29 15:06:26 localhost systemd[1]: Starting resolvconf-pull-resolved.service... Oct 29 15:06:26 localhost systemd[1]: Starting Network Manager Script Dispatcher Service... Oct 29 15:06:26 localhost pppd[21738]: IPCP terminated by peer (Refused our IP address) Oct 29 15:06:26 localhost pppd[21738]: Connect time 0.0 minutes. Oct 29 15:06:26 localhost pppd[21738]: Sent 0 bytes, received 26 bytes. Oct 29 15:06:26 localhost systemd[1]: Started resolvconf-pull-resolved.service. Oct 29 15:06:26 localhost dbus-daemon[989]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher' Oct 29 15:06:26 localhost systemd[1]: Started Network Manager Script Dispatcher Service. Oct 29 15:06:26 localhost nm-dispatcher: req:1 'vpn-up' [ppp0]: new request (3 scripts) Oct 29 15:06:26 localhost nm-dispatcher: req:1 'vpn-up' [ppp0]: start running ordered scripts... Oct 29 15:06:26 localhost NetworkManager[14390]: <info> [1572361586.3337] device (ppp0): state change: disconnected -> unmanaged (reason 'connection-assumed', sys-iface-state: 'external') Oct 29 15:06:26 localhost pppd[21738]: LCP terminated by peer (No network protocols running) Oct 29 15:06:26 localhost pppd[21738]: Overriding mtu 1500 to 1400 Oct 29 15:06:26 localhost pppd[21738]: Overriding mru 1500 to mtu value 1400 Oct 29 15:06:26 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:26 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:26 localhost nm-applet[2826]: Can't set a parent on widget which has a parent Oct 29 15:06:29 localhost pppd[21738]: Connection terminated. Oct 29 15:06:29 localhost NetworkManager[14390]: xl2tpd[21737]: death_handler: Fatal signal 15 received Oct 29 15:06:29 localhost NetworkManager[14390]: <info> [1572361589.3653] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: VPN plugin: state changed: stopping (5) Oct 29 15:06:29 localhost NetworkManager[14390]: xl2tpd[21737]: Terminating pppd: sending TERM signal to pid 21738 Oct 29 15:06:29 localhost NetworkManager[14390]: xl2tpd[21737]: Connection 37101 closed to <IP removed>, port 1701 (Server closing) Oct 29 15:06:29 localhost NetworkManager[14390]: 002 "d730a197-b3da-4763-8add-98a67338dadc": deleting non-instance connection Oct 29 15:06:29 localhost NetworkManager[14390]: 002 "d730a197-b3da-4763-8add-98a67338dadc" #2: deleting state (STATE_QUICK_I2) and sending notification Oct 29 15:06:29 localhost NetworkManager[14390]: 005 "d730a197-b3da-4763-8add-98a67338dadc" #2: ESP traffic information: in=3KB out=3KB Oct 29 15:06:29 localhost NetworkManager[14390]: <info> [1572361589.3782] devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0) Oct 29 15:06:29 localhost NetworkManager[14390]: 002 "d730a197-b3da-4763-8add-98a67338dadc" #1: deleting state (STATE_MAIN_I4) and sending notification Oct 29 15:06:29 localhost pppd[21738]: Terminating on signal 15 Oct 29 15:06:29 localhost pppd[21738]: Modem hangup Oct 29 15:06:29 localhost pppd[21738]: Exit. Oct 29 15:06:29 localhost nm-l2tp-service[21051]: ipsec shut down Oct 29 15:06:29 localhost NetworkManager[14390]: <info> [1572361589.4093] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",9:(ppp0)]: VPN plugin: state changed: stopped (6) Oct 29 15:06:29 localhost nm-dispatcher: req:2 'vpn-down' [ppp0]: new request (3 scripts) Oct 29 15:06:29 localhost nm-dispatcher: req:2 'vpn-down' [ppp0]: start running ordered scripts... Oct 29 15:06:29 localhost NetworkManager[14390]: <info> [1572361589.4264] vpn-connection[0x55919a9e61c0,d730a197-b3da-4763-8add-98a67338dadc,"VPN connection 1",0]: VPN service disappeared Oct 29 15:06:29 localhost systemd[1]: Starting resolvconf-pull-resolved.service... Oct 29 15:06:29 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:29 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:29 localhost nm-applet[2826]: Can't set a parent on widget which has a parent Oct 29 15:06:29 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:29 localhost nm-applet[2826]: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed Oct 29 15:06:29 localhost systemd[1]: Started resolvconf-pull-resolved.service. Oct 29 15:06:29 localhost nm-applet[2826]: Can't set a parent on widget which has a parent     I have tried using   libreswan strongswan   with and without   3des-sha1-modp1024 3des-sha1   and adding ! to the end of the above.   Am I missing something obvious?   ... View more