L2TP IPSec VPN IPSec Ubuntu 14 64位

[alroyso]

连接不上，调试模式:
xl2tpd[36435]: Connection established to 113.56.227.255, 59675. Local: 3062, Remote: 2 (ref=0/0). LNS session is 'default'
xl2tpd[36435]: start_pppd: I'm running:
xl2tpd[36435]: "/usr/sbin/pppd"
xl2tpd[36435]: "passive"
xl2tpd[36435]: "nodetach"
xl2tpd[36435]: "10.9.0.1:10.9.0.30"
xl2tpd[36435]: "refuse-pap"
xl2tpd[36435]: "refuse-chap"
xl2tpd[36435]: "auth"
xl2tpd[36435]: "name"
xl2tpd[36435]: "DefaultL2TPServer"
xl2tpd[36435]: "file"
xl2tpd[36435]: "/etc/ppp/l2tpd-options"
xl2tpd[36435]: "/dev/pts/3"
xl2tpd[36435]: Call established with 113.56.227.255, Local: 16881, Remote: 5193, Serial: 1
/usr/sbin/pppd: The remote system is required to authenticate itself
/usr/sbin/pppd: but I couldn't find any suitable secret (password) for it to use to do so.
xl2tpd[36435]: child_handler : pppd exited for call 5193 with code 1
xl2tpd[36435]: call_close: Call 16881 to 113.56.227.255 disconnected

出现一下症状，请问这个 是什么问题呀