如何設置 OpenVPN 伺服器以像代理一樣工作

我正在嘗試在 Amazon EC2 上設置 openvpn。要檢查它，我正在使用http://whatismyipaddress.com。

目前我可以通過以下方式連接到我的遠端伺服器：

sudo openvpn --config /etc/openvpn/openvpnuser1.conf

連接後伺服器日誌有：

Sun Jun 11 08:44:06 2017 us=235368 GET INST BY REAL: 176.XX.193.73:54967 [succeeded]
Sun Jun 11 08:44:06 2017 us=235386 user1/176.XX.193.73:54967 UDPv4 READ [69] from [AF_INET]176.XX.193.73:54967: P_DATA_V1 kid=0 DATA 117650fd 4f53ac24 d1614c31 f40cd5d1 49c86aa0 066fc87e 7e1db1fb 47321f9[more...]
Sun Jun 11 08:44:06 2017 us=235393 user1/176.XX.193.73:54967 TLS: tls_pre_decrypt, key_id=0, IP=[AF_INET]176.XX.193.73:54967
Sun Jun 11 08:44:06 2017 us=235405 user1/176.XX.193.73:54967 DECRYPT IV: 066fc87e 7e1db1fb 47321f94 d4f764ee
Sun Jun 11 08:44:06 2017 us=235416 user1/176.XX.193.73:54967 DECRYPT TO: 00000008 fa2a187b f3641eb4 cb07ed2d 0a981fc7 48
Sun Jun 11 08:44:06 2017 us=235425 user1/176.XX.193.73:54967 PID_TEST [0] [SSL-0] [>EEEEEE] 0:7 0:8 t=1497170646[0] r=[0,64,15,0,1] sl=[57,7,64,528]
Sun Jun 11 08:44:06 2017 us=235431 user1/176.XX.193.73:54967 RECEIVED PING PACKET
Sun Jun 11 08:44:06 2017 us=235437 PO_CTL rwflags=0x0001 ev=4 arg=0x55687fb01180
Sun Jun 11 08:44:06 2017 us=235441 PO_CTL rwflags=0x0001 ev=5 arg=0x55687fb01068
Sun Jun 11 08:44:06 2017 us=235448 I/O WAIT TR|Tw|SR|Sw [8/142628]

客戶端還提出了額外的介面並獲得了 IP 地址（ifconfig）：

tun1      Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
         inet addr:10.0.0.6  P-t-P:10.0.0.5  Mask:255.255.255.255
         UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
         RX packets:0 errors:0 dropped:0 overruns:0 frame:0
         TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:100 
         RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

所以，我假設 openvpn 連接已經建立。但不幸的是，http://whatismyipaddress.com仍然顯示我的（客戶端）真實 IP 添加。

---

客戶端配置：

client
dev tun
proto udp
remote 52.XX.48.224 1194
resolv-retry infinite
nobind
persist-key
persist-tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/user1.crt
key /etc/openvpn/user1.key
tls-auth /etc/openvpn/ccd/ta.key 1
cipher AES-256-CBC
ns-cert-type server
comp-lzo
log /var/log/openvpn.log
verb 3
sndbuf 0
rcvbuf 0

伺服器配置：

port 1194
proto udp
dev tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/ServerV1.crt
key /etc/openvpn/ServerV1.key
dh /etc/openvpn/dh2048.pem
tls-auth /etc/openvpn/ccd/ta.key 0
cipher AES-256-CBC
server 10.0.0.0 255.255.255.0
keepalive 10 120
persist-key
persist-tun
client-config-dir /etc/openvpn/ccd
status ServerV1-status.log
log /var/log/ServerV1.log
sndbuf 0
rcvbuf 0
push "redirect-geteway def1"
push "dhcp-options DNS 8.8.8.8"
comp-lzo
verb 15

啟用伺服器轉發

cat /proc/sys/net/ipv4/conf/all/forwarding
1

iptables 編輯：

iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -o eth1 -j MASQUERADE
iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
MASQUERADE  all  --  ip-10-0-0-0.eu-central-1.compute.internal/24  anywhere

您的伺服器配置中似乎有錯字：

   push "redirect-geteway def1"

應該

   push "redirect-gateway def1"

這很可能是客戶端在建立隧道後沒有通過隧道設置預設路由的原因。

希望能幫助到你！

人力資源管理系統。我認為您可能希望在 iptables 配置中更加明確。

#Allow new OpenVPN connections from the outside
iptables -A INPUT -i eth1 -m state --state NEW -p udp --dport 1194 -j ACCEPT
# Allow all tun interfaces to talk to me
iptables -A input -i tun+ -j ACCEPT
# And to talk through me
iptables -A FORWARD -i tun+ -j ACCEPT
iptables -A FORWARD -i tun+ -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i eth1 -o tun+ -m state --state RELATED,ESTABLISHED -j ACCEPT

在您的 conf 頂部應該修復您…您的預設策略無處不在，並且您的偽裝線在我看來還不錯…您的流量一旦被協商（0 RX/0 TX）就不會通過隧道，因為您沒有在輸入鏈中添加任何內容….

引用自：https://serverfault.com/questions/855110