sudo /usr/lib/NetworkManager/nm-l2tp-service --debug
nm-l2tp[689590] <debug> nm-l2tp-service (version 1.8.6) starting...
nm-l2tp[689590] <debug>  uses default --bus-name "org.freedesktop.NetworkManager.l2tp"
nm-l2tp[689590] <info>  ipsec enable flag: yes
** Message: 09:22:07.607: Check port 1701
vpn
	data : {'gateway': '*addr*', 'ipsec-enabled': 'yes', 'ipsec-esp': '3des-sha1', 'ipsec-forceencaps': 'yes', 'ipsec-ike': '3des-sha1-modp1024', 'ipsec-psk': '*pre_shared_pass*', 'mru': '1400', 'mtu': '1400', 'password-flags': '0', 'user': '*username*'}
	secrets : {'password': '*password*'}
	service-type : 'org.freedesktop.NetworkManager.l2tp'

proxy

ipv6
	address-data : []
	dns : []
	dns-search : []
	method : 'auto'
	route-data : []

connection
	id : 'spotonf'
	permissions : []
	type : 'vpn'
	uuid : 'ffcdc390-c875-491f-a54b-5cf66c0762ed'

ipv4
	address-data : []
	dns : []
	dns-search : []
	method : 'auto'
	route-data : []

nm-l2tp[689590] <info>  starting ipsec
Stopping strongSwan IPsec failed: starter is not running
Starting strongSwan 5.9.1 IPsec [starter]...
Loading config setup
Loading conn 'ffcdc390-c875-491f-a54b-5cf66c0762ed'
nm-l2tp[689590] <info>  Spawned ipsec up script with PID 689652.
initiating Main Mode IKE_SA ffcdc390-c875-491f-a54b-5cf66c0762ed[1] to *addr*
generating ID_PROT request 0 [ SA V V V V V ]
sending packet: from 192.168.1.137[500] to *addr*[500] (236 bytes)
received packet: from *addr*[500] to 192.168.1.137[500] (156 bytes)
parsed ID_PROT response 0 [ SA V V V V ]
received XAuth vendor ID
received NAT-T (RFC 3947) vendor ID
received DPD vendor ID
received FRAGMENTATION vendor ID
selected proposal: IKE:3DES_CBC/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
generating ID_PROT request 0 [ KE No NAT-D NAT-D ]
sending packet: from 192.168.1.137[500] to *addr*[500] (244 bytes)
received packet: from *addr*[500] to 192.168.1.137[500] (228 bytes)
parsed ID_PROT response 0 [ KE No NAT-D NAT-D ]
local host is behind NAT, sending keep alives
generating ID_PROT request 0 [ ID HASH ]
sending packet: from 192.168.1.137[4500] to *addr*[4500] (68 bytes)
received packet: from *addr*[4500] to 192.168.1.137[4500] (92 bytes)
parsed ID_PROT response 0 [ ID HASH V ]
received DPD vendor ID
IKE_SA ffcdc390-c875-491f-a54b-5cf66c0762ed[1] established between 192.168.1.137[192.168.1.137]...*addr*[*addr*]
scheduling reauthentication in 10230s
maximum IKE_SA lifetime 10770s
generating QUICK_MODE request 644858499 [ HASH SA No ID ID NAT-OA NAT-OA ]
sending packet: from 192.168.1.137[4500] to *addr*[4500] (244 bytes)
received packet: from *addr*[4500] to 192.168.1.137[4500] (172 bytes)
parsed QUICK_MODE response 644858499 [ HASH SA No ID ID NAT-OA NAT-OA ]
selected proposal: ESP:3DES_CBC/HMAC_SHA1_96/NO_EXT_SEQ
CHILD_SA ffcdc390-c875-491f-a54b-5cf66c0762ed{1} established with SPIs c5890210_i 0425b01c_o and TS 192.168.1.137/32[udp/l2f] === *addr*/32[udp/l2f]
connection 'ffcdc390-c875-491f-a54b-5cf66c0762ed' established successfully
nm-l2tp[689590] <info>  strongSwan IPsec tunnel is up.
** Message: 09:22:11.434: xl2tpd started with pid 689663
xl2tpd[689663]: Not looking for kernel SAref support.
xl2tpd[689663]: Using l2tp kernel support.
xl2tpd[689663]: xl2tpd version xl2tpd-1.3.16 started on halee PID:689663
xl2tpd[689663]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc.
xl2tpd[689663]: Forked by Scott Balmos and David Stipp, (C) 2001
xl2tpd[689663]: Inherited by Jeff McAdams, (C) 2002
xl2tpd[689663]: Forked again by Xelerance (www.xelerance.com) (C) 2006-2016
xl2tpd[689663]: Listening on IP address 0.0.0.0, port 1701
xl2tpd[689663]: get_call: allocating new tunnel for host *addr*, port 1701.
xl2tpd[689663]: Connecting to host *addr*, port 1701
xl2tpd[689663]: control_finish: message type is (null)(0).  Tunnel is 0, call is 0.
xl2tpd[689663]: control_finish: sending SCCRQ
xl2tpd[689663]: message_type_avp: message type 2 (Start-Control-Connection-Reply)
xl2tpd[689663]: protocol_version_avp: peer is using version 1, revision 0.
xl2tpd[689663]: framing_caps_avp: supported peer frames: async sync
xl2tpd[689663]: bearer_caps_avp: supported peer bearers: analog digital
xl2tpd[689663]: firmware_rev_avp: peer reports firmware version 264 (0x0108)
xl2tpd[689663]: hostname_avp: peer reports hostname 'mE0CBBC046F9D'
xl2tpd[689663]: vendor_avp: peer reports vendor 'Katalix Systems Ltd. Linux-3.18.66-meraki-x86 (x86_64)'
xl2tpd[689663]: assigned_tunnel_avp: using peer's tunnel 21664
xl2tpd[689663]: receive_window_size_avp: peer wants RWS of 10.  Will use flow control.
xl2tpd[689663]: control_finish: message type is Start-Control-Connection-Reply(2).  Tunnel is 21664, call is 0.
xl2tpd[689663]: control_finish: sending SCCCN
xl2tpd[689663]: Connection established to *addr*, 1701.  Local: 37638, Remote: 21664 (ref=0/0).
xl2tpd[689663]: Calling on tunnel 37638
xl2tpd[689663]: control_finish: message type is (null)(0).  Tunnel is 21664, call is 0.
xl2tpd[689663]: control_finish: sending ICRQ
xl2tpd[689663]: message_type_avp: message type 11 (Incoming-Call-Reply)
xl2tpd[689663]: assigned_call_avp: using peer's call 7738
xl2tpd[689663]: control_finish: message type is Incoming-Call-Reply(11).  Tunnel is 21664, call is 7738.
xl2tpd[689663]: control_finish: Sending ICCN
xl2tpd[689663]: Call established with *addr*, Local: 23288, Remote: 7738, Serial: 1 (ref=0/0)
xl2tpd[689663]: start_pppd: I'm running:
xl2tpd[689663]: "/usr/sbin/pppd"
xl2tpd[689663]: "plugin"
xl2tpd[689663]: "pppol2tp.so"
xl2tpd[689663]: "pppol2tp"
xl2tpd[689663]: "7"
xl2tpd[689663]: "passive"
xl2tpd[689663]: "nodetach"
xl2tpd[689663]: ":"
xl2tpd[689663]: "debug"
xl2tpd[689663]: "file"
xl2tpd[689663]: "/var/run/nm-l2tp-ffcdc390-c875-491f-a54b-5cf66c0762ed/ppp-options"
xl2tpd[689663]: message_type_avp: message type 16 (Set-Link-Info)
xl2tpd[689663]: ignore_avp : Ignoring AVP
xl2tpd[689663]: control_finish: message type is Set-Link-Info(16).  Tunnel is 21664, call is 7738.
nm-l2tp[689590] <info>  Terminated xl2tpd daemon with PID 689663.
xl2tpd[689663]: death_handler: Fatal signal 15 received
xl2tpd[689663]: Terminating pppd: sending TERM signal to pid 689664
xl2tpd[689663]: Connection 21664 closed to *addr*, port 1701 (Server closing)
Stopping strongSwan IPsec...
** Message: 09:22:13.063: ipsec shut down
nm-l2tp[689590] <warn>  xl2tpd exited with error code 1
Stopping strongSwan IPsec failed: starter is not running
** Message: 09:22:13.073: ipsec shut down