xl2tpd client cannot connect with death_handler: Fatal signal 15

[Bradley-Drummonds]

We are using NetworkManager-l2tp/strongswan/xl2tp on our linux client

Versions
nm-l2tp-service: 1.2.18
xl2tpd version: 1.3.9
strongSwan 5.5.3
pppd 2.4.7

We are building our linux client using Yocto, and an old kernel, 3.1.10-2.8.7+g5e3cb65 .
The server we are trying to connect is an old windows 2008 server , but has no problem serving clients on iOS, WinCE, android.... The server traces show that a header has incorrect size, but we currently don't have more info from the server side.

Below is the output from nm-l2tp-service --debug

nm-l2tp[749] nm-l2tp-service (version 1.2.18) starting...
nm-l2tp[749] uses default --bus-name "org.freedesktop.NetworkManager.l2tp"
nm-l2tp[749] ipsec enable flag: yes
** Message: Check port 1701
connection
id : "vpn2" (s)
uuid : "5c912719-67d6-4bdb-b5eb-d5f3db641814" (s)
interface-name : NULL (sd)
type : "vpn" (s)
permissions : [] (s)
autoconnect : TRUE (sd)
autoconnect-priority : 0 (sd)
timestamp : 0 (sd)
read-only : FALSE (sd)
zone : NULL (sd)
master : NULL (sd)
slave-type : NULL (sd)
autoconnect-slaves : ((NMSettingConnectionAutoconnectSlaves) NM_SETTING_CONNECTION_AUTOCONNECT_SLAVES_DEFAULT) (sd)
secondaries : [] (s)
gateway-ping-timeout : 0 (sd)
metered : ((NMMetered) NM_METERED_UNKNOWN) (sd)
lldp : -1 (sd)
stable-id : NULL (sd)

ipv6
method : "auto" (s)
dns : [] (s)
dns-search : [] (s)
dns-options : NULL (sd)
dns-priority : 0 (sd)
addresses : ((GPtrArray*) 0x3a008) (s)
gateway : NULL (sd)
routes : ((GPtrArray*) 0x42109c08) (s)
route-metric : -1 (sd)
ignore-auto-routes : FALSE (sd)
ignore-auto-dns : FALSE (sd)
dhcp-hostname : NULL (sd)
dhcp-send-hostname : TRUE (sd)
never-default : FALSE (sd)
may-fail : TRUE (sd)
dad-timeout : -1 (sd)
dhcp-timeout : 0 (sd)
ip6-privacy : ((NMSettingIP6ConfigPrivacy) NM_SETTING_IP6_CONFIG_PRIVACY_UNKNOWN) (sd)
addr-gen-mode : 1 (sd)
token : NULL (sd)

ipv4
method : "auto" (s)
dns : [] (s)
dns-search : [] (s)
dns-options : NULL (sd)
dns-priority : 0 (sd)
addresses : ((GPtrArray*) 0x421098a8) (s)
gateway : NULL (sd)
routes : ((GPtrArray*) 0x52548) (s)
route-metric : -1 (sd)
ignore-auto-routes : FALSE (sd)
ignore-auto-dns : FALSE (sd)
dhcp-hostname : NULL (sd)
dhcp-send-hostname : TRUE (sd)
never-default : FALSE (sd)
may-fail : TRUE (sd)
dad-timeout : -1 (sd)
dhcp-timeout : 0 (sd)
dhcp-client-id : NULL (sd)
dhcp-fqdn : NULL (sd)

vpn
service-type : "org.freedesktop.NetworkManager.l2tp" (s)
user-name : "" (s)
persistent : FALSE (sd)
data : ((GHashTable*) 0x4dac0) (s)
secrets : ((GHashTable*) 0x4da50) (s)
timeout : 0 (sd)

nm-l2tp[749] starting ipsec
Stopping strongSwan IPsec failed: starter is not running
Starting strongSwan ..3 IPsec [starter]...
Loading config setup
Loading conn '5c912719-67d6-4bdb-b5eb-d5f3db641814'
found netkey IPsec stack
nm-l2tp[749] Spawned ipsec up script with PID 817.
initiating Main Mode IKE_SA 5c912719-67d6-4bdb-b5eb-d5f3db641814[1] to redacted
generating ID_PROT request 0 [ SA V V V V V ]
sending packet: from [500] to (532 bytes)
received packet: from to [500] (212 bytes)
parsed ID_PROT response 0 [ SA V V V V V V ]
received MS NT5 ISAKMPOAKLEY vendor ID
received NAT-T (RFC 3947) vendor ID
received draft-ietf-ipsec-nat-t-ike-02\n vendor ID
received FRAGMENTATION vendor ID
received unknown vendor ID: fb:1d:e3:cd:f3:41:b7:ea:16:b7:e5:be:08:55:f1:20
received unknown vendor ID: e3:a5:96:6a:76:37:9f:e7:07:22:82:31:e5:ce::52
generating ID_PROT request 0 [ KE No NAT-D NAT-D ]
sending packet: from [500] to (212 bytes)
received packet: from to [500] (228 bytes)
parsed ID_PROT response 0 [ KE No NAT-D NAT-D ]
local host is behind NAT, sending keep alives
remote host is behind NAT
generating ID_PROT request 0 [ ID HASH ]
sending packet: from 10.42.78.122[4500] to redacted[4500] (76 bytes)
received packet: from redacted[4500] to 10.42.78.122[4500] (76 bytes)
parsed ID_PROT response 0 [ ID HASH ]
IKE_SA 5c912719-67d6-4bdb-b5eb-d5f3db641814[1] established between 10.42.78.122[10.42.78.122]...redacted[192.168.90.90]
scheduling reauthentication in 10221s
maximum IKE_SA lifetime 10761s
generating QUICK_MODE request 1672764256 [ HASH SA No ID ID NAT-OA NAT-OA ]
sending packet: from 10.42.78.122[4500] to redacted[4500] (252 bytes)
received packet: from redacted[4500] to 10.42.78.122[4500] (220 bytes)
parsed QUICK_MODE response 1672764256 [ HASH SA No ID ID NAT-OA NAT-OA ]
connection '5c912719-67d6-4bdb-b5eb-d5f3db641814' established successfully
nm-l2tp[749] strongSwan IPsec tunnel is up.
** Message: xl2tpd started with pid 844
xl2tpd[844]: setsockopt recvref[30]: Protocol not available
xl2tpd[844]: This binary does not support kernel L2TP.
xl2tpd[844]: xl2tpd version xl2tpd-1.3.9 started on colibri-t30 PID:844
xl2tpd[844]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc.
xl2tpd[844]: Forked by Scott Balmos and David Stipp, (C) 2001
xl2tpd[844]: Inherited by Jeff McAdams, (C) 2002
xl2tpd[844]: Forked again by Xelerance (www.xelerance.com) (C) 2006-2016
xl2tpd[844]: Listening on IP address 0.0.0.0, port 1701
xl2tpd[844]: get_call: allocating new tunnel for host redacted, port 1701.
xl2tpd[844]: Connecting to host redacted, port 1701
xl2tpd[844]: control_finish: message type is (null)(0). Tunnel is 0, call is 0.
xl2tpd[844]: control_finish: sending SCCRQ
xl2tpd[844]: message_type_avp: message type 2 (Start-Control-Connection-Reply)
xl2tpd[844]: protocol_version_avp: peer is using version 1, revision 0.
xl2tpd[844]: framing_caps_avp: supported peer frames: sync
xl2tpd[844]: bearer_caps_avp: supported peer bearers:
xl2tpd[844]: firmware_rev_avp: peer reports firmware version 1537 (0x0601)
xl2tpd[844]: hostname_avp: peer reports hostname 'WS2008R2-WH1'
xl2tpd[844]: vendor_avp: peer reports vendor 'Microsoft'
xl2tpd[844]: assigned_tunnel_avp: using peer's tunnel 298
xl2tpd[844]: receive_window_size_avp: peer wants RWS of 8. Will use flow control.
xl2tpd[844]: control_finish: message type is Start-Control-Connection-Reply(2). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending SCCCN
xl2tpd[844]: Connection established to redacted, 1701. Local: 29027, Remote: 298 (ref=0/0).
xl2tpd[844]: Calling on tunnel 29027
xl2tpd[844]: control_finish: message type is (null)(0). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending ICRQ
xl2tpd[844]: message_type_avp: message type 11 (Incoming-Call-Reply)
xl2tpd[844]: assigned_call_avp: using peer's call 2
xl2tpd[844]: control_finish: message type is Incoming-Call-Reply(11). Tunnel is 298, call is 2.
xl2tpd[844]: control_finish: Sending ICCN
xl2tpd[844]: Call established with redacted, Local: 21420, Remote: 2, Serial: 1 (ref=0/0)
** Message: nm-l2tp-ppp-plugin: (plugin_init): initializing
** Message: nm-l2tp-ppp-plugin: (nm_phasechange): status 3 / phase 'serial connection'
** Message: nm-l2tp-ppp-plugin: (nm_phasechange): status / phase 'establish'
xl2tpd[844]: message_type_avp: message type 2 (Start-Control-Connection-Reply)
xl2tpd[844]: protocol_version_avp: peer is using version 1, revision 0.
xl2tpd[844]: framing_caps_avp: supported peer frames: sync
xl2tpd[844]: bearer_caps_avp: supported peer bearers:
xl2tpd[844]: firmware_rev_avp: peer reports firmware version 1537 (0x0601)
xl2tpd[844]: hostname_avp: peer reports hostname 'WS2008R2-WH1'
xl2tpd[844]: vendor_avp: peer reports vendor 'Microsoft'
xl2tpd[844]: assigned_tunnel_avp: using peer's tunnel 298
xl2tpd[844]: receive_window_size_avp: peer wants RWS of 8. Will use flow control.
xl2tpd[844]: control_finish: message type is Start-Control-Connection-Reply(2). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending SCCCN
xl2tpd[844]: Connection established to redacted, 1701. Local: 29027, Remote: 298 (ref=0/0).
xl2tpd[844]: Calling on tunnel 29027
xl2tpd[844]: control_finish: message type is (null)(0). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending ICRQ
xl2tpd[844]: message_type_avp: message type 2 (Start-Control-Connection-Reply)
xl2tpd[844]: protocol_version_avp: peer is using version 1, revision 0.
xl2tpd[844]: framing_caps_avp: supported peer frames: sync
xl2tpd[844]: bearer_caps_avp: supported peer bearers:
xl2tpd[844]: firmware_rev_avp: peer reports firmware version 1537 (0x0601)
xl2tpd[844]: hostname_avp: peer reports hostname 'WS2008R2-WH1'
xl2tpd[844]: vendor_avp: peer reports vendor 'Microsoft'
xl2tpd[844]: assigned_tunnel_avp: using peer's tunnel 298
xl2tpd[844]: receive_window_size_avp: peer wants RWS of 8. Will use flow control.
xl2tpd[844]: control_finish: message type is Start-Control-Connection-Reply(2). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending SCCCN
xl2tpd[844]: Connection established to redacted, 1701. Local: 29027, Remote: 298 (ref=0/0).
xl2tpd[844]: Calling on tunnel 29027
xl2tpd[844]: control_finish: message type is (null)(0). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending ICRQ
xl2tpd[844]: message_type_avp: message type 2 (Start-Control-Connection-Reply)
xl2tpd[844]: protocol_version_avp: peer is using version 1, revision 0.
xl2tpd[844]: framing_caps_avp: supported peer frames: sync
xl2tpd[844]: bearer_caps_avp: supported peer bearers:
xl2tpd[844]: firmware_rev_avp: peer reports firmware version 1537 (0x0601)
xl2tpd[844]: hostname_avp: peer reports hostname 'WS2008R2-WH1'
xl2tpd[844]: vendor_avp: peer reports vendor 'Microsoft'
xl2tpd[844]: assigned_tunnel_avp: using peer's tunnel 298
xl2tpd[844]: receive_window_size_avp: peer wants RWS of 8. Will use flow control.
xl2tpd[844]: control_finish: message type is Start-Control-Connection-Reply(2). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending SCCCN
xl2tpd[844]: Connection established to redacted5..210, 1701. Local: 29027, Remote: 298 (ref=0/0).
xl2tpd[844]: Calling on tunnel 29027
xl2tpd[844]: control_finish: message type is (null)(0). Tunnel is 298, call is 0.
xl2tpd[844]: control_finish: sending ICRQ
nm-l2tp[749] Looks like pppd didn't initialize our dbus module
xl2tpd[844]: death_handler: Fatal signal 15 received
** Message: nm-l2tp-ppp-plugin: (nm_phasechange): status 11 / phase 'disconnect'
nm-l2tp[749] Terminated xl2tpd daemon with PID 844.
** Message: nm-l2tp-ppp-plugin: (nm_phasechange): status 1 / phase 'dead'
** Message: nm-l2tp-ppp-plugin: (nm_exit_notify): cleaning up
Stopping strongSwan IPsec...
** Message: ipsec shut down
nm-l2tp[749] xl2tpd exited with error code 1
Stopping strongSwan IPsec failed: starter is not running
** Message: ipsec shut down

Thanks for your help