Openvpn
OpenVPN 停止在突尼斯載入網站
我已經設置 OpenVPN 好幾年了。我在世界各地有三台電腦連接到中央伺服器（OVH France），我一直在使用它在它們之間進行通信並路由所有網際網路流量，一直以來只有小問題。至少我覺得我有…
今天，我飛往突尼斯，到達，但無法載入任何網頁。如果我在手機上連接到同一個連接，我可以很好地載入它們（它不在 VPN 上），如果我在筆記型電腦頁面上禁用 OpenVPN，則會立即載入。但是，這不是 VPN 沒有連接的簡單情況，因為我知道它是。我可以：
- 平網站。
- Tracert 到他們，第一跳顯示為我的中央伺服器。
- 使用其內部 VPN IP SSH 到該伺服器。
- 再次使用他們的 VPN IP 連接到 VPN 上任何其他電腦上的文件共享。
- 當通過 SSH 連接到伺服器時，我可以 ping 和 curl 任何網頁。
- 我還可以從我的機器上捲曲頁面；但是，那是在一個 docker 容器中，所以我有一種感覺（也從那裡查看 tracert）這是繞過 VPN（我需要解決的問題，但不是目前的問題）。
我的理解是所有流量都通過同一個隧道路由，所以我不明白一些（samba、ping、ssh）如何能正常工作，而 http/https 根本不起作用。
我的客戶端配置：
############################################## # Sample client-side OpenVPN 2.0 config file # # for connecting to multi-client server. # # # # This configuration can be used by multiple # # clients, however each client should have # # its own cert and key files. # # # # On Windows, you might want to rename this # # file so it has a .ovpn extension # ############################################## # Specify that we are a client and that we # will be pulling certain config file directives # from the server. client # Use the same setting as you are using on # the server. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun # Windows needs the TAP-Windows adapter name # from the Network Connections panel # if you have more than one. On XP SP2, # you may need to disable the firewall # for the TAP adapter. ;dev-node MyTap # Are we connecting to a TCP or # UDP server? Use the same setting as # on the server. ;proto tcp proto udp # The hostname/IP and port of the server. # You can have multiple remote entries # to load balance between the servers. ;remote 176.58.100.178 1194 remote 217.182.67.172 1194 ;remote my-server-2 1194 # Choose a random host from the remote # list for load-balancing. Otherwise # try hosts in the order specified. ;remote-random # Keep trying indefinitely to resolve the # host name of the OpenVPN server. Very useful # on machines which are not permanently connected # to the internet such as laptops. resolv-retry infinite # Most clients don't need to bind to # a specific local port number. nobind # Downgrade privileges after initialization (non-Windows only) ;user nobody ;group nobody # Try to preserve some state across restarts. persist-key persist-tun # If you are connecting through an # HTTP proxy to reach the actual OpenVPN # server, put the proxy server/IP and # port number here. See the man page # if your proxy server requires # authentication. ;http-proxy-retry # retry on connection failures ;http-proxy [proxy server] [proxy port #] # Wireless networks often produce a lot # of duplicate packets. Set this flag # to silence duplicate packet warnings. ;mute-replay-warnings # SSL/TLS parms. # See the server config file for more # description. It's best to use # a separate .crt/.key file pair # for each client. A single ca # file can be used for all clients. ca ../EasyRSA/pki/ca.crt cert ../EasyRSA/pki/issued/Boomer.crt key ../EasyRSA/pki/private/Boomer.key # Verify server certificate by checking # that the certicate has the nsCertType # field set to "server". This is an # important precaution to protect against # a potential attack discussed here: # http://openvpn.net/howto.html#mitm # # To use this feature, you will need to generate # your server certificates with the nsCertType # field set to "server". The build-key-server # script in the easy-rsa folder will do this. remote-cert-tls server # If a tls-auth key is used on the server # then every client must also have the key. tls-auth ../EasyRSA/pki/ta.key 1 # Select a cryptographic cipher. # If the cipher option is used on the server # then you must also specify it here. ;cipher x cipher AES-256-CBC ;tls-cipher TLS-DHE-RSA-WITH-AES-256-GCM-SHA384 ;tls-cipher TLS-DHE-RSA-WITH-AES-256-CBC-SHA256 ;tls-cipher TLS-DHE-RSA-WITH-AES-128-GCM-SHA256 ;tls-cipher TLS-DHE-RSA-WITH-AES-128-CBC-SHA256 # Enable compression on the VPN link. # Don't enable this unless it is also # enabled in the server config file. comp-lzo # Set log file verbosity. verb 3 # Silence repeating messages ;mute 20 #block-outside-dns redirect-gateway def1 #route 10.96.42.0/24 #route 0.0.0.0 0.0.0.0 vpn_gateway 999我的伺服器配置：
################################################# # Sample OpenVPN 2.0 config file for # # multi-client server. # # # # This file is for the server side # # of a many-clients one-server # # OpenVPN configuration. # # # # OpenVPN also supports # # single-machine single-machine # # configurations (See the Examples page # # on the web site for more info). # # # # This config should work on Windows # # or Linux/BSD systems. Remember on # # Windows to quote pathnames and use # # double backslashes, e.g.: # # "C:\\Program Files\\OpenVPN\\config\\foo.key" # # # # Comments are preceded with '#' or ';' # ################################################# # Which local IP address should OpenVPN # listen on? (optional) ;local a.b.c.d # Which TCP/UDP port should OpenVPN listen on? # If you want to run multiple OpenVPN instances # on the same machine, use a different port # number for each one. You will need to # open up this port on your firewall. port 1194 # TCP or UDP server? ;proto tcp proto udp # "dev tun" will create a routed IP tunnel, # "dev tap" will create an ethernet tunnel. # Use "dev tap0" if you are ethernet bridging # and have precreated a tap0 virtual interface # and bridged it with your ethernet interface. # If you want to control access policies # over the VPN, you must create firewall # rules for the the TUN/TAP interface. # On non-Windows systems, you can give # an explicit unit number, such as tun0. # On Windows, use "dev-node" for this. # On most systems, the VPN will not function # unless you partially or fully disable # the firewall for the TUN/TAP interface. ;dev tap dev tun0 iproute /usr/local/sbin/unpriv-ip persist-tun # Windows needs the TAP-Windows adapter name # from the Network Connections panel if you # have more than one. On XP SP2 or higher, # you may need to selectively disable the # Windows firewall for the TAP adapter. # Non-Windows systems usually don't need this. ;dev-node MyTap # SSL/TLS root certificate (ca), certificate # (cert), and private key (key). Each client # and the server must have their own cert and # key file. The server and all clients will # use the same ca file. # # See the "easy-rsa" directory for a series # of scripts for generating RSA certificates # and private keys. Remember to use # a unique Common Name for the server # and each of the client certificates. # # Any X509 key management system can be used. # OpenVPN can also use a PKCS #12 formatted key file # (see "pkcs12" directive in man page). ca EasyRSA/pki/ca.crt cert EasyRSA/pki/issued/Ellen-Tigh.crt key EasyRSA/pki/private/Ellen-Tigh.key # This file should be kept secret # Diffie hellman parameters. # Generate your own with: # openssl dhparam -out dh1024.pem 1024 # Substitute 2048 for 1024 if you are using # 2048 bit keys. ;dh /etc/openvpn/dh.pem dh EasyRSA/pki/dh.pem # Configure server mode and supply a VPN subnet # for OpenVPN to draw client addresses from. # The server will take 10.8.0.1 for itself, # the rest will be made available to clients. # Each client will be able to reach the server # on 10.8.0.1. Comment this line out if you are # ethernet bridging. See the man page for more info. server 10.96.42.0 255.255.255.0 # Maintain a record of client virtual IP address # associations in this file. If OpenVPN goes down or # is restarted, reconnecting clients can be assigned # the same virtual IP address from the pool that was # previously assigned. ifconfig-pool-persist ipp.txt # Configure server mode for ethernet bridging. # You must first use your OS's bridging capability # to bridge the TAP interface with the ethernet # NIC interface. Then you must manually set the # IP/netmask on the bridge interface, here we # assume 10.8.0.4/255.255.255.0. Finally we # must set aside an IP range in this subnet # (start=10.8.0.50 end=10.8.0.100) to allocate # to connecting clients. Leave this line commented # out unless you are ethernet bridging. ;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100 # Push routes to the client to allow it # to reach other private subnets behind # the server. Remember that these # private subnets will also need # to know to route the OpenVPN client # address pool (10.8.0.0/255.255.255.0) # back to the OpenVPN server. ;push "route 192.168.10.0 255.255.255.0" ;push "route 192.168.20.0 255.255.255.0" # To assign specific IP addresses to specific # clients or if a connecting client has a private # subnet behind it that should also have VPN access, # use the subdirectory "ccd" for client-specific # configuration files (see man page for more info). # EXAMPLE: Suppose the client # having the certificate common name "Thelonious" # also has a small subnet behind his connecting # machine, such as 192.168.40.128/255.255.255.248. # First, uncomment out these lines: client-config-dir clients ;route 10.96.42.0 255.255.255.0 # Then create a file ccd/Thelonious with this line: # iroute 192.168.40.128 255.255.255.248 # This will allow Thelonious' private subnet to # access the VPN. This example will only work # if you are routing, not bridging, i.e. you are # using "dev tun" and "server" directives. # EXAMPLE: Suppose you want to give # Thelonious a fixed VPN IP address of 10.9.0.1. # First uncomment out these lines: ;client-config-dir ccd ;route 10.9.0.0 255.255.255.252 # Then add this line to ccd/Thelonious: # ifconfig-push 10.9.0.1 10.9.0.2 # Suppose that you want to enable different # firewall access policies for different groups # of clients. There are two methods: # (1) Run multiple OpenVPN daemons, one for each # group, and firewall the TUN/TAP interface # for each group/daemon appropriately. # (2) (Advanced) Create a script to dynamically # modify the firewall in response to access # from different clients. See man # page for more info on learn-address script. ;learn-address ./script # If enabled, this directive will configure # all clients to redirect their default # network gateway through the VPN, causing # all IP traffic such as web browsing and # and DNS lookups to go through the VPN # (The OpenVPN server machine may need to NAT # the TUN/TAP interface to the internet in # order for this to work properly). # CAVEAT: May break client's network config if # client's local DHCP server packets get routed # through the tunnel. Solution: make sure # client's local DHCP server is reachable via # a more specific route than the default route # of 0.0.0.0/0.0.0.0. push "redirect-gateway def1" push "route 10.96.42.0 255.255.255.0" push "remote-gateway 10.96.42.1" # Certain Windows-specific network settings # can be pushed to clients, such as DNS # or WINS server addresses. CAVEAT: # http://openvpn.net/faq.html#dhcpcaveats push "dhcp-option DNS 10.96.42.1" push "dhcp-option WINS 10.96.42.1" # Uncomment this directive to allow different # clients to be able to "see" each other. # By default, clients will only see the server. # To force clients to only see the server, you # will also need to appropriately firewall the # server's TUN/TAP interface. client-to-client # Uncomment this directive if multiple clients # might connect with the same certificate/key # files or common names. This is recommended # only for testing purposes. For production use, # each client should have its own certificate/key # pair. # # IF YOU HAVE NOT GENERATED INDIVIDUAL # CERTIFICATE/KEY PAIRS FOR EACH CLIENT, # EACH HAVING ITS OWN UNIQUE "COMMON NAME", # UNCOMMENT THIS LINE OUT. ;duplicate-cn # The keepalive directive causes ping-like # messages to be sent back and forth over # the link so that each side knows when # the other side has gone down. # Ping every 10 seconds, assume that remote # peer is down if no ping received during # a 120 second time period. keepalive 10 120 # For extra security beyond that provided # by SSL/TLS, create an "HMAC firewall" # to help block DoS attacks and UDP port flooding. # # Generate with: # openvpn --genkey --secret ta.key # # The server and each client must have # a copy of this key. # The second parameter should be '0' # on the server and '1' on the clients. tls-auth EasyRSA/pki/ta.key 0 # This file is secret # Select a cryptographic cipher. # This config item must be copied to # the client config file as well. ;cipher BF-CBC # Blowfish (default) ;cipher AES-128-CBC # AES ;cipher DES-EDE3-CBC # Triple-DES cipher AES-256-CBC # Enable compression on the VPN link. # If you enable it here, you must also # enable it in the client config file. comp-lzo # The maximum number of concurrently connected # clients we want to allow. max-clients 8 # It's a good idea to reduce the OpenVPN # daemon's privileges after initialization. # # You can uncomment this out on # non-Windows systems. user nobody group nogroup # The persist options will try to avoid # accessing certain resources on restart # that may no longer be accessible because # of the privilege downgrade. persist-key persist-tun # Output a short status file showing # current connections, truncated # and rewritten every minute. status openvpn-status.log # By default, log messages will go to the syslog (or # on Windows, if running as a service, they will go to # the "\Program Files\OpenVPN\log" directory). # Use log or log-append to override this default. # "log" will truncate the log file on OpenVPN startup, # while "log-append" will append to it. Use one # or the other (but not both). log openvpn.log ;log /etc/openvpn/openvpn.log ;log-append openvpn.log # Set the appropriate level of log # file verbosity. # # 0 is silent, except for fatal errors # 4 is reasonable for general usage # 5 and 6 can help to debug connection problems # 9 is extremely verbose verb 3 # Silence repeating messages. At most 20 # sequential messages of the same message # category will be output to the log. ;mute 20 chroot /etc/openvpn/jail tmp-dir tmp正如我也說過的，我多年來一直在使用這個設置，沒有任何問題。從字面上看，唯一改變的是我的國家。這不是我嘗試使用它的第一個外國，有很多 - 這是我首先獲得 VPN 的部分原因。
編輯：
我還安裝了teamviewer，因此能夠遠端控製網路上的另一台PC，在英國。那台電腦可以完美連接網站，檢查時，它的IP被報告為中央伺服器的IP。所以我真的不相信這是一個伺服器端的問題，因為其他機器仍然表現正確。
也許您遇到了 MTU 問題：嘗試降低本地連接的 MTU。您可能還必須降低隧道內的 MTU。
作為參考，將其添加到客戶端和伺服器配置中都有效：
# Limit the MTU size. fragment 1400 mssfix 1400