Sep 5 14:31:50 root charon: 13[ENC] generating QUICK_MODE request 3930082374 [ HASH ]
Sep 5 14:31:50 root charon: 13[NET] sending packet: from 10.18.99.33[4500] to 128.88.33.11[4500] (60 bytes)
Sep 5 14:31:50 root NetworkManager[932]: nm-l2tp[26025] <info> strongSwan IPsec tunnel is up.
Sep 5 14:31:50 root NetworkManager[932]: ** Message: xl2tpd started with pid 26104
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Not looking for kernel SAref support.
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Using l2tp kernel support.
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: xl2tpd version xl2tpd-1.3.6 started on root PID:26104
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc.
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Forked by Scott Balmos and David Stipp, (C) 2001
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Inherited by Jeff McAdams, (C) 2002
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Forked again by Xelerance (www.xelerance.com) (C) 2006
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Listening on IP address 0.0.0.0, port 1701
Sep 5 14:31:50 root NetworkManager[932]: xl2tpd[26104]: Connecting to host 128.88.33.11, port 1701
Sep 5 14:31:50 root NetworkManager[932]: <info> [1536129110.8589] vpn-connection[0x2207460,c700dc45-2bc6-4e83-a50a-7fdacfd4ac19,"VPN connection 1",0]: VPN plugin: state changed: starting (3)
Sep 5 14:31:55 root NetworkManager[932]: xl2tpd[26104]: Maximum retries exceeded for tunnel 33925. Closing.
Sep 5 14:31:55 root NetworkManager[932]: xl2tpd[26104]: Connection 0 closed to 128.88.33.11, port 1701 (Timeout)
Sep 5 14:32:00 root NetworkManager[932]: xl2tpd[26104]: Unable to deliver closing message for tunnel 33925. Destroying anyway.
Sep 5 14:32:04 root NetworkManager[932]: nm-l2tp[26025] <warn> Looks like pppd didn't initialize our dbus module
Sep 5 14:32:04 root NetworkManager[932]: nm-l2tp[26025] <info> Terminated xl2tpd daemon with PID 26104.
Sep 5 14:32:04 root NetworkManager[932]: xl2tpd[26104]: death_handler: Fatal signal 15 received
在/etc/ipsec.conf里的L2TP-PSK-noNAT中加上
dpddelay=40
dpdtimeout=130
dpdaction=clear