即使流量双向流动，OpenVPN 客户端也会由于 --ping-restart 重新连接

Question

情况：

• 具有公共 IP 的 OpenVPN (2.3.12) 服务器1.1.1.1在 Amazon EC2 中运行，使用 UDP 协议。
• 具有公共 IP 的远程 OpenVPN (2.3.10) 客户端，2.2.2.2位于 ADSL 连接上的某个位置，位于 wifi 家用路由器和防火墙后面。

问题是客户端会每 40 秒重新连接一次，即使连接似乎工作正常。

正如您在下面看到的，我们已经keepalive 10 40在服务器上进行了配置，并将其适当地推送到客户端。我可以更改该值，但当然我们确实希望客户端在连接实际中断时重新连接（例如，wifi 路由器已重新启动并忘记了所有有状态的 UDP 规则）。所以这不是一个好的选择。

即使我ssh通过 VPN连接到客户端并通过在 中上下滚动产生一些流量less，或者如果我ping通过 VPN连续运行到客户端，也会发生断开连接。

我们也遇到了由 MTU 大小引起的数据包丢失的问题，但这已通过mssfix 1200在客户端上使用得到解决。作为记录，客户端可以使用以下命令 ping 服务器（VPN 外）

ping -M do -s 1412 -c 1 1.1.1.1

所以我们的mssfix值理论上可以根据这个答案设置为1372 ；1200 只是为了增加安全余量（因此我们可以在其他网络上的其他客户端上重用此配置）。

从客户端日志：

[server] Inactivity timeout (--ping-restart), restarting
TCP/UDP: Closing socket
SIGUSR1[soft,ping-restart] received, process restarting
Restart pause, 2 second(s)
Re-using SSL/TLS context
LZO compression initialized
Control Channel MTU parms [ L:1558 D:1212 EF:38 EB:0 ET:0 EL:3 ]
Socket Buffers: R=[212992->212992] S=[212992->212992]
Data Channel MTU parms [ L:1558 D:1200 EF:58 EB:143 ET:0 EL:3 AF:3/1 ]
Local Options String: 'V4,dev-type tun,link-mtu 1558,tun-mtu 1500,proto UDPv4,comp-lzo,cipher AES-256-CBC,auth SHA1,keysize 256,key-method 2,tls-client'
Expected Remote Options String: 'V4,dev-type tun,link-mtu 1558,tun-mtu 1500,proto UDPv4,comp-lzo,cipher AES-256-CBC,auth SHA1,keysize 256,key-method 2,tls-server'
Local Options hash (VER=V4): '22188c5b'
Expected Remote Options hash (VER=V4): 'a8f55717'
UDPv4 link local: [undef]
UDPv4 link remote: [AF_INET]1.1.1.1:1194
TLS: Initial packet from [AF_INET]1.1.1.1:1194, sid=78ff051d c8d027a7
VERIFY OK: depth=1, CN=REDACTED
Validating certificate key usage
++ Certificate has key usage  00a0, expects 00a0
VERIFY KU OK
Validating certificate extended key usage
++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication
VERIFY EKU OK
VERIFY OK: depth=0, CN=server
Data Channel Encrypt: Cipher 'AES-256-CBC' initialized with 256 bit key
Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Data Channel Decrypt: Cipher 'AES-256-CBC' initialized with 256 bit key
Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Control Channel: TLSv1.2, cipher TLSv1/SSLv3 DHE-RSA-AES256-GCM-SHA384, 2048 bit RSA
[server] Peer Connection Initiated with [AF_INET]1.1.1.1:1194
SENT CONTROL [server]: 'PUSH_REQUEST' (status=1)
PUSH: Received control message: 'PUSH_REPLY,route-gateway 10.84.0.1,topology subnet,ping 10,ping-restart 40,ifconfig 10.84.0.6 255.255.0.0'
OPTIONS IMPORT: timers and/or timeouts modified
OPTIONS IMPORT: --ifconfig/up options modified
OPTIONS IMPORT: route-related options modified
Preserving previous TUN/TAP instance: tun0
Initialization Sequence Completed

从服务器日志：

MULTI: multi_create_instance called
93.254.95.157:33098 Re-using SSL/TLS context
93.254.95.157:33098 LZO compression initialized
93.254.95.157:33098 Control Channel MTU parms [ L:1558 D:1212 EF:38 EB:0 ET:0 EL:3 ]
93.254.95.157:33098 Data Channel MTU parms [ L:1558 D:1450 EF:58 EB:143 ET:0 EL:3 AF:3/1 ]
93.254.95.157:33098 Local Options String: 'V4,dev-type tun,link-mtu 1558,tun-mtu 1500,proto UDPv4,comp-lzo,cipher AES-256-CBC,auth SHA1,keysize 256,key-method 2,tls-server'
93.254.95.157:33098 Expected Remote Options String: 'V4,dev-type tun,link-mtu 1558,tun-mtu 1500,proto UDPv4,comp-lzo,cipher AES-256-CBC,auth SHA1,keysize 256,key-method 2,tls-client'
93.254.95.157:33098 Local Options hash (VER=V4): 'a8f55717'
93.254.95.157:33098 Expected Remote Options hash (VER=V4): '22188c5b'
93.254.95.157:33098 TLS: Initial packet from [AF_INET]93.254.95.157:33098, sid=a3383b01 bc17f487
93.254.95.157:33098 VERIFY OK: depth=1, CN=REDACTED
93.254.95.157:33098 VERIFY OK: depth=0, CN=ClientName
93.254.95.157:33098 Data Channel Encrypt: Cipher 'AES-256-CBC' initialized with 256 bit key
93.254.95.157:33098 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
93.254.95.157:33098 Data Channel Decrypt: Cipher 'AES-256-CBC' initialized with 256 bit key
93.254.95.157:33098 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
93.254.95.157:33098 Control Channel: TLSv1.2, cipher TLSv1/SSLv3 DHE-RSA-AES256-GCM-SHA384, 2048 bit RSA
93.254.95.157:33098 [ClientName] Peer Connection Initiated with [AF_INET]93.254.95.157:33098
MULTI: new connection by client 'ClientName' will cause previous active sessions by this client to be dropped.  Remember to use the --duplicate-cn option if you want multiple clients using the same certificate or username to concurrently connect.
MULTI_sva: pool returned IPv4=10.84.0.6, IPv6=(Not enabled)
MULTI: Learn: 10.84.0.6 -> ClientName/2.2.2.2:33098
MULTI: primary virtual IP for ClientName/2.2.2.2:33098: 10.84.0.6
ClientName/2.2.2.2:33098 PUSH: Received control message: 'PUSH_REQUEST'
ClientName/2.2.2.2:33098 send_push_reply(): safe_cap=940
ClientName/2.2.2.2:33098 SENT CONTROL [ClientName]: 'PUSH_REPLY,route-gateway 10.84.0.1,topology subnet,ping 10,ping-restart 40,ifconfig 10.84.0.6 255.255.0.0' (status=1)

客户端配置：

client
dev tun
proto udp
remote 1.1.1.1 1194
resolv-retry infinite
nobind
user nobody
group nogroup
persist-key
persist-tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/client.crt
key /etc/openvpn/client.key
remote-cert-tls server
cipher AES-256-CBC
comp-lzo
verb 4
mssfix 1200

服务器配置：

port 1194
proto udp
dev tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key
dh /etc/openvpn/dh.pem
topology subnet
server 10.84.0.0 255.255.0.0
ifconfig-pool-persist ipp.txt
client-to-client
keepalive 10 40
cipher AES-256-CBC
comp-lzo
user nobody
group nobody
persist-key
persist-tun
status openvpn-status.log
verb 4

我也许可以通过切换到 TCP 而不是 UDP 来解决这个问题，但是我对开销和风险很警惕，并且觉得即使它最终有效，它也是一个愚蠢的“解决方案”。

关于在哪里看和尝试什么的任何其他想法？

Answer 1

你知道有什么帮助吗？不在openvpn客户端机器上同时运行两个客户端进程。第一个会重新连接，然后服务器忘记第二个并停止 ping 它，所以第二个最终会重新连接，依此类推......

我现在觉得有点傻，但我会留下这个，以防其他人也同样傻。