有人用OpenSwan配置过IPSec的VPN吗？

按照https://raymii.org/s/tutorials/IPSEC_L2TP_vpn_with_Ubuntu_12.04.html上面的教程在DO的VPS上配置完成，然后无法连接（服务器无响应），提示

packet from xx.xx.xx.xx:61330: initial Main Mode message received on xx.xx.xx.xx:500 but no connection has been authorized with policy=PSK

然后根据官方WiKi上改动了一些，现在是Disconnected by the communication device.查看log发现变成了这样：

Dec 27 03:11:20 username pluto[2985]: "L2TP-PSK-noNAT"[1] xx.xx.xx.xx #2: STATE_QUICK_R2: IPsec SA established transport mode {ESP=>0x0fa3c77a <0xb00f70e3 xfrm=AES_256-HMAC_SHA1 NATOA=none NATD=xx.xx.xx.xx:33170 DPD=none}
Dec 27 03:11:41 username pluto[2985]: "L2TP-PSK-NAT"[2] xx.xx.xx.xx #1: received Delete SA(0x0fa3c77a) payload: deleting IPSEC State #2
Dec 27 03:11:41 username pluto[2985]: "L2TP-PSK-NAT"[2] xx.xx.xx.xx #1: deleting connection "L2TP-PSK-noNAT" instance with peer xx.xx.xx.xx {isakmp=#0/ipsec=#0}

求指点，感谢