L2TP配置

配置L2TP服务端，按照阿里给的配置脚本(l2tp.sh)，完整的执行了一遍。
但是，无论手机还是PC端都无法正常连接，折腾了好几天了，头发都白了。


1、ipsec verify正常：

Checking your system to see if IPsec got installed and started correctly:
Version check and ipsec on-path                                 [OK]
Linux Openswan U2.6.38/K3.10.0-514.26.2.el7.x86_64 (netkey)
Checking for IPsec support in kernel                            [OK]
SAref kernel support                                           [N/A]
NETKEY:  Testing XFRM related proc values                      [OK]
        [OK]
        [OK]
Hardware RNG detected, testing if used properly                 [OK]
Checking that pluto is running                                  [OK]
Pluto listening for IKE on udp 500                             [OK]
Pluto listening for NAT-T on udp 4500                          [OK]
Checking for 'ip' command                                       [OK]
Checking /bin/sh is not /bin/dash                               [OK]
Checking for 'iptables' command                                 [OK]
Opportunistic Encryption Support                                [DISABLED]


2、tail -f /var/log/secure，看到有报错如下：

Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-06] meth=111, but already using method 115
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-05] meth=110, but already using method 115
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-04] meth=109, but already using method 115
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-03] meth=108, but already using method 115
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02] meth=107, but already using method 115
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [draft-ietf-ipsec-nat-t-ike-02_n] meth=106, but already using method 115
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: ignoring Vendor ID payload [FRAGMENTATION 80000000]
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: received Vendor ID payload [Dead Peer Detection]
Nov 16 22:40:42 izj6c6h25ghj5n6vo0emwnz pluto[3070]: packet from 221.222.9.47:500: initial Main Mode message received on 172.31.232.230:500 but no connection has been authorized with policy=PSK


尝试了很多方法，无论如何都无法解决，愁死我了！哪位大师可否指点一下？
不胜感激！！