我正在为我的工程学位做一个项目，需要我与一些现有的设备进行交互，所以我的选择相当有限。我对 VPN 和 ipsec 还不太熟悉。如果我完全搞错了，请告诉我。我已尽力阅读手册页和文档。
我正在尝试将蜂窝 3G 路由器 (Moxa OnCell 5104-HSPA) 连接到 Amazon EC2 云中的 VPN 服务器，以在任一网络上的两个设备之间提供端到端访问。3G 路由器支持带 PSK 的 IPSec VPN。困难的部分是，我目前没有蜂窝路由器的静态、面向公众的 IP。获取该 IP 正在准备中，但我正在尝试看看能否让它同时工作。如果没有公共静态 IP 地址就无法做到这一点，请告诉我。
[ Openswan VPN Server ] ---> internet ---> Cellular NAT(s) ---> [ Cellular Router ]
^ ^
| |
[ End User ] [ Remote Device ]
蜂窝路由器似乎仅支持站点到站点 VPN 配置。我有它成功连接 （见下文）到 VPN 网络，但我不确定如何从 VPN 的任一端获取数据包路由。
从 /var/log/auth.log 确认连接 （在此示例中，更改了 IP：
172.31.0.1 = EC2 IP (VPN server)
22.22.22.22 = Cellular NAT
10.185.42.114 = 3G Router
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: responding to Main Mode from unknown peer 22.22.22.22
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: STATE_MAIN_R1: sent MR1, expecting MI2
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: NAT-Traversal: Result using draft-ietf-ipsec-nat-t-ike (MacOS X): both are NATed
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: transition from state STATE_MAIN_R1 to state STATE_MAIN_R2
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: STATE_MAIN_R2: sent MR2, expecting MI3
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: Main mode peer ID is ID_IPV4_ADDR: '10.185.42.114'
pluto[11336]: "RWConn"[7] 22.22.22.22 #11: switched from "RWConn" to "RWConn"
pluto[11336]: "RWConn"[8] 22.22.22.22 #11: deleting connection "RWConn" instance with peer 22.22.22.22 {isakmp=#0/ipsec=#0}
pluto[11336]: "RWConn"[8] 22.22.22.22 #11: transition from state STATE_MAIN_R2 to state STATE_MAIN_R3
pluto[11336]: "RWConn"[8] 22.22.22.22 #11: new NAT mapping for #11, was 22.22.22.22:52862, now 22.22.22.22:46828
pluto[11336]: "RWConn"[8] 22.22.22.22 #11: STATE_MAIN_R3: sent MR3, ISAKMP SA established {auth=OAKLEY_PRESHARED_KEY cipher=oakley_3des_cbc_192 prf=oakley_sha group=modp1536}
pluto[11336]: "RWConn"[8] 22.22.22.22 #11: Dead Peer Detection (RFC 3706): enabled
pluto[11336]: "RWConn"[8] 22.22.22.22 #11: the peer proposed: 10.0.1.0/24:17/1701 -> 10.0.50.0/24:17/0
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: responding to Quick Mode proposal
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: us: 172.31.0.1/32===172.31.0.1<172.31.0.1>:17/1701---172.31.0.1
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: them: 22.22.22.22[10.185.42.114]:17/0
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: transition from state STATE_QUICK_R0 to state STATE_QUICK_R1
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: STATE_QUICK_R1: sent QR1, inbound IPsec SA installed, expecting QI2
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: Dead Peer Detection (RFC 3706): enabled
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: transition from state STATE_QUICK_R1 to state STATE_QUICK_R2
pluto[11336]: "RWConn"[8] 22.22.22.22 #12: STATE_QUICK_R2: IPsec SA established transport mode {ESP/NAT=>0x********* <0x********** xfrm=3DES_0-HMAC_SHA1 NATOA=none NATD=22.22.22.22:46828 DPD=enabled}
** 因此，此时，我相信我已经正确连接了 VPN 客户端，但我不确定下一步该去哪里设置设备之间的数据包转发 **
ipsec.conf 和相关文件可以根据需要提供。我想让我的初始帖子保持简洁。