Strongswan与Andriod野蛮模式L2TPoverIPsec对接有时候不成功。

不成功的时候strongswan打印如下：

Dec 17 13:55:12 05[ENC] generating AGGRESSIVE response 0 [ SA KE No ID V V V NAT-D NAT-D HASH ]

Dec 17 13:55:12 05[NET] sending packet: from 192.168.0.132[500] to 192.168.0.124[500] (384 bytes)

Dec 17 13:55:12 04[NET] sending packet: from 192.168.0.132[500] to 192.168.0.124[500]

Dec 17 13:55:12 05[MGR] checkin IKE_SA net-net[8]

Dec 17 13:55:12 05[MGR] check-in of IKE_SA successful.

Dec 17 13:55:12 01[JOB] next event in 3s 999ms, waiting

Dec 17 13:55:13 03[NET] received packet: from 192.168.0.124[500] to 192.168.0.132[500]

Dec 17 13:55:13 03[NET] waiting for data on sockets

Dec 17 13:55:13 03[NET] received packet: from 192.168.0.124[500] to 192.168.0.132[500]

Dec 17 13:55:13 03[NET] waiting for data on sockets

Dec 17 13:55:13 06[MGR] checkout IKE_SA by message

Dec 17 13:55:13 06[MGR] IKE_SA net-net[8] successfully checked out

Dec 17 13:55:13 06[NET] received packet: from 192.168.0.124[500] to 192.168.0.132[500] (92 bytes)

Dec 17 13:55:13 06[ENC] parsed INFORMATIONAL_V1 request 2630201173 [ HASH N(INITIAL_CONTACT) ]

Dec 17 13:55:13 06[IKE] calculated HASH does not match HASH payload

Dec 17 13:55:13 06[CFG] no alternative config found

Dec 17 13:55:13 06[IKE] queueing ISAKMP_DELETE task

Dec 17 13:55:13 06[IKE] activating new tasks

Dec 17 13:55:13 06[IKE]   activating ISAKMP_DELETE task

Dec 17 13:55:13 06[IKE] deleting IKE_SA net-net[8] between 192.168.0.132[192.168.0.132]...192.168.0.124[123]

Dec 17 13:55:13 06[IKE] sending DELETE for IKE_SA net-net[8]

Dec 17 13:55:13 06[IKE] IKE_SA net-net[8] state change: CONNECTING => DELETING

Dec 17 13:55:13 06[ENC] generating INFORMATIONAL_V1 request 3988102021 [ HASH D ]

Dec 17 13:55:13 06[NET] sending packet: from 192.168.0.132[500] to 192.168.0.124[500] (84 bytes)

Dec 17 13:55:13 06[MGR] checkin and destroy IKE_SA net-net[8]

Dec 17 13:55:13 06[IKE] IKE_SA net-net[8] state change: DELETING => DESTROYING

Dec 17 13:55:13 06[MGR] check-in and destroy of IKE_SA successful

可以看出，原本应该期待收到AGG的第三条报文，但是却收到了个通知载荷 N(INITIAL_CONTACT) ]。通过抓包发现Andriod（racoon）确实也发了，

在strongswan的接收机器上通过tcpdump抓包如下顺序。

agg1/agg2/agg3/info

但是strongswan却先收到了information报文，导致处理错误。。。。谨记一下。