我正在尝试在我的桌面和运行 Linux（Ubuntu）的 AWS 服务器之间建立一个 VPN（Strongswan + xl2tpd），但我真的迷路了。
我相信我可以让 IPSec 部分工作，但我并不完全相信，因为 l2tp 部分不工作并且似乎没有在日志中显示任何内容。
我使用以下方式建立 IPSec 隧道
$ ipsec up AWSVPN
然后：
$ ipsec status
Security Associations (1 up, 0 connecting):
AWSVPN[3]: ESTABLISHED 17 minutes ago, 192.168.1.150[robin.blah.blah]...52.x.x.91[vpn.blah.blah]
AWSVPN{7}: INSTALLED, TUNNEL, ESP in UDP SPIs: ca867b64_i cda2db1d_o
AWSVPN{7}: 10.0.1.123/32 === 10.0.0.0/23
尝试 l2tp 部分：
$ echo "c awsvpn" > /var/run/xl2tpd/l2tp-control
我在客户端系统日志中收到此信息：
Jul 15 13:18:37 H61N-USB3 xl2tpd[10340]: get_call: allocating new tunnel for host 52.25.35.91, port 1701.
Jul 15 13:18:37 H61N-USB3 xl2tpd[10340]: Connecting to host 52.x.x.91, port 1701
Jul 15 13:18:37 H61N-USB3 xl2tpd[10340]: control_finish: message type is (null)(0). Tunnel is 0, call is 0.
Jul 15 13:18:37 H61N-USB3 xl2tpd[10340]: control_finish: sending SCCRQ
Jul 15 13:18:38 H61N-USB3 xl2tpd[10340]: network_thread: select timeout
Jul 15 13:18:42 H61N-USB3 xl2tpd[10340]: message repeated 4 times: [ network_thread: select timeout]
Jul 15 13:18:42 H61N-USB3 xl2tpd[10340]: Maximum retries exceeded for tunnel 65296. Closing.
Jul 15 13:18:42 H61N-USB3 xl2tpd[10340]: Connection 0 closed to 52.x.x.91, port 1701 (Timeout)
Jul 15 13:18:43 H61N-USB3 xl2tpd[10340]: network_thread: select timeout
Jul 15 13:18:47 H61N-USB3 xl2tpd[10340]: message repeated 4 times: [ network_thread: select timeout]
Jul 15 13:18:47 H61N-USB3 xl2tpd[10340]: Unable to deliver closing message for tunnel 65296. Destroying anyway.
在服务器上我什么也没得到。
Jul 15 12:14:06 ip-172-31-38-36 xl2tpd[4751]: xl2tpd version xl2tpd-1.3.6 started on ip-172-31-38-36 PID:4751
Jul 15 12:14:06 ip-172-31-38-36 xl2tpd[4751]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc.
Jul 15 12:14:06 ip-172-31-38-36 xl2tpd[4751]: Forked by Scott Balmos and David Stipp, (C) 2001
Jul 15 12:14:06 ip-172-31-38-36 xl2tpd[4751]: Inherited by Jeff McAdams, (C) 2002
Jul 15 12:14:06 ip-172-31-38-36 xl2tpd[4751]: Forked again by Xelerance (www.xelerance.com) (C) 2006
Jul 15 12:14:06 ip-172-31-38-36 xl2tpd[4751]: Listening on IP address 0.0.0.0, port 1701
我认为一定是我遗漏了某些步骤。有人能帮忙吗？