好记性不如烂笔头，OpenVPN的配置真是一Google/baidu就一大堆。
由于教研室需要VPN，所以在网上找了OpenVpn的安装配置。经过两天在网上查找资料，配置成功可以通过vpn代理上网。
安装OpenVpn2.1.1
在进行操作之前，首先进行初始化工作：
修改C:\Program Files\OPENVPN\easy-rsa\vars.bat.sample的以下部分
set HOME=%ProgramFiles%\OpenVPN\easy-rsa
set KEY_COUNTRY=US
set KEY_PROVINCE=CA
set KEY_CITY=SanFrancisco
set KEY_ORG=FortFunston
set [email protected]
（请根据自身情况修改）改为
set HOME=C:\Program Files\OPENVPN\easy-rsa
set KEY_COUNTRY=CN #(国家)
set KEY_PROVINCE=GuangDong #(省份)
set KEY_CITY=ShenZhen #(城市)
set KEY_ORG=oovc.com #(组织)
set [email protected] #(邮件地址)
上面#开始的是注释，请不要写到文件中。
打开命令提示符：
开始-->运行...-->键入cmd，回车，进入命令提示符
或者 开始-->程序-->附件-->命令提示符
进入openvpn\easy-rsa目录。
命令如下：
c: 回车
cd \openvpn\easy-rsa 回车
init-config
vars
clean-all
上面是初始化工作，以后，在进行证书制作工作时，仍旧需要进行初始化，
但只需要进入openvpn\easy-rsa目录，运行vars就可以了，不需要上面那些
步骤了 。
下面开始证书的制作：
生成根证书
build-ca
build-dh
生成服务端密钥
build-key-server server
生成客户端密钥
build-key client （根据client不同，可生成多个。比如build-key client2.......）
注意：在输入参数时，Common Name 不要与生成其他证书时相同，否则会出错
生成的密钥存放于openvpn\easy\rsa\keys目录下
接下来开始配置服务器
将生成的ta.key, ca.crt,dh1024.pem,server.crt,server.key复制到\OPENVPN\config目录下
这四个文件是服务端运行所需要的文件。
ta.key, ca.crt ,client.crt, client.key 是客户端所需要的文件，复制到客户端\OPENVPN\config目录下
服务器端server.ovpn文件的内容：
# 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 tun
dev tap
# Windows needs the TAP-Win32 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 ca.crt
cert server.crt
key server.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 dh1024.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 192.168.0.0 255.255.255.0
# 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
# Configure server mode for ethernet bridging
# using a DHCP-proxy, where clients talk
# to the OpenVPN server-side DHCP server
# to receive their IP address allocation
# and DNS server addresses. You must first use
# your OS's bridging capability to bridge the TAP
# interface with the ethernet NIC interface.
# Note: this mode only works on clients (such as
# Windows), where the client-side TAP adapter is
# bound to a DHCP client.
;server-bridge
# 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 ccd
;route 192.168.40.128 255.255.255.248
# 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
# or bridge the TUN/TAP interface to the internet
# in order for this to work properly).
;push "redirect-gateway def1 bypass-dhcp"
# Certain Windows-specific network settings
# can be pushed to clients, such as DNS
# or WINS server addresses. CAVEAT:
# http://openvpn.net/faq.html#dhcpcaveats
# The addresses below refer to the public
# DNS servers provided by opendns.com.
;push "dhcp-option DNS 208.67.222.222"
;push "dhcp-option DNS 208.67.220.220"
# 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 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
# 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 100
# 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 nobody
# 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 "C:\\Program Files\\OpenVPN\\config\\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-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
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客户端client.ovpn的内容：
client
dev tap
proto udp
remote 121.49.110.10 1194
resolv-retry infinite
nobind
user nobody
group nobody
#下面两行是设置路由表，也可以在server.ovpn里面用push "route 0.0.0.0 0.0.0.0"和push"route 192.168.1.0 255.255.255.0"
route 0.0.0.0 0.0.0.0
route 192.168.1.0 255.255.255.0
persist-key
persist-tun
#同样，下面这一行也可以在服务端push
redirect-gateway def1
ca ca.crt
cert client2.crt
key client2.key
ns-cert-type server
tls-auth ta.key 1
comp-lzo
# Set log file verbosity
verb 3
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到此OpenVPN虽然配置完成，可以成功组成虚拟个人网，客户端（192.168.0.2）和服务器(192.168.0.1)可以ping通。但客户端还不能通过服务器代理访问外网。为了达到这个目的现需要在服务器端开启NAT服务。
Windows开启NAT请参考下博客：单网卡开启nat（配合openvpn）