1. 關閉SELINUX

 setenforce0      //暫時關閉 sed -i '^SELINUX=/c\SELINUX=disabled'  /etc/selinux/config      //重啟有效

2.安裝"EPEL"源

 wget http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm     //下載centos6 32位的EPEL源 rpm -ivh epel-release-6-8.noarch.rpm     //安裝EPEL源 yum makecache     //更新本地緩存

3. 安裝openvpn

yum -y install openvpn easy-rsa

4. easy-rsa配置

 mkdir -p /etc/openvpn/easy-rsa/keys cp -rf/usr/share/easy-rsa/2.0/* /etc/openvpn/easy-rsa/

5. 創建CA證書和密鑰

 vi /etc/openvpn/easy-rsa/vars         //更改你自己的國家，省份，城市，郵箱等... source  ./vars         //初始化證書的授權中心 ./clean-all           //清除keys目錄下面的文件 ./build-ca         //創建ca證書Generating a 1024 bit RSA private key.++++++......................++++++writing new private key to 'ca.key'-----You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is what is called a Distinguished Name or a DN.There are quite a few fields but you can leave some blankFor some fields there will be a default value,If you enter '.', the field will be left blank.-----Country Name (2 letter code) [CN]:State or Province Name (full name) [CA]:Locality Name (eg, city) [HZ]:Organization Name (eg, company) [HZ]:Organizational Unit Name (eg, section) [changeme]:Common Name (eg, your name or your server's hostname) [changeme]:Name [changeme]:Email Address [[email protected]]:

6.創建服務端的證書和密鑰

./build-key-server serverGenerating a 1024 bit RSA private key.....++++++.................++++++writing new private key to 'server.key'-----You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is what is called a Distinguished Name or a DN.There are quite a few fields but you can leave some blankFor some fields there will be a default value,If you enter '.', the field will be left blank.-----Country Name (2 letter code) [CN]:State or Province Name (full name) [CA]:Locality Name (eg, city) [HZ]:Organization Name (eg, company) [HZ]:Organizational Unit Name (eg, section) [changeme]:Common Name (eg, your name or your server's hostname) [server]:Name [changeme]:Email Address [[email protected]]:  Please enter the following 'extra' attributesto be sent with your certificate requestA challenge password []:An optional company name []:Using configuration from /etc/easy-rsa/2.0/openssl.cnfCheck that the request matches the signatureSignature okThe Subject's Distinguished Name is as followscountryName           :PRINTABLE:'CN'stateOrProvinceName   :PRINTABLE:'CA'localityName          :PRINTABLE:'HZ'organizationName      :PRINTABLE:'HZ'organizationalUnitName:PRINTABLE:'changeme'commonName            :PRINTABLE:'server'name                  :PRINTABLE:'changeme'emailAddress          :IA5STRING:'[email protected]'Certificate is to be certified until Mar 28 03:05:21 2022 GMT (3650 days)Sign the certificate? [y/n]:y      1 out of 1 certificate requests certified, commit? [y/n]y  Write out database with 1 new entriesData Base Update

7.創建客戶端的證書和密鑰

./build-key client1Generating a 1024 bit RSA private key...++++++...............++++++writing new private key to 'client1.key'-----You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is what is called a Distinguished Name or a DN.There are quite a few fields but you can leave some blankFor some fields there will be a default value,If you enter '.', the field will be left blank.-----Country Name (2 letter code) [CN]:State or Province Name (full name) [CA]:Locality Name (eg, city) [HZ]:Organization Name (eg, company) [HZ]:Organizational Unit Name (eg, section) [changeme]:Common Name (eg, your name or your server's hostname) [client1]:Name [changeme]:Email Address [[email protected]]:  Please enter the following 'extra' attributesto be sent with your certificate requestA challenge password []:An optional company name []:Using configuration from /etc/easy-rsa/2.0/openssl.cnfCheck that the request matches the signatureSignature okThe Subject's Distinguished Name is as followscountryName           :PRINTABLE:'CN'stateOrProvinceName   :PRINTABLE:'CA'localityName          :PRINTABLE:'HZ'organizationName      :PRINTABLE:'HZ'organizationalUnitName:PRINTABLE:'changeme'commonName            :PRINTABLE:'client1'name                  :PRINTABLE:'changeme'emailAddress          :IA5STRING:'[email protected]'Certificate is to be certified until Mar 28 03:21:06 2022 GMT (3650 days)Sign the certificate? [y/n]:y      1 out of 1 certificate requests certified, commit? [y/n]y  Write out database with 1 new entriesData Base Updated

8.創建迪菲霍爾曼密鑰交換參數

 ./build-dh

9.拷貝服務端證書、秘鑰等

 cp /etc/openvpn/easy-rsa/keys/{server.crt,server.key,dh2048.pem,ca.crt} /etc/openvpn

10.配置VPN服務端

 cp /usr/share/doc/openvpn-2.3.*/sample/sample-config-files/server.conf/etc/openvpn/     //復制配置文件到/etc/openvpn

修改服務端配置文件：

 cat server.conf | grep "^[^#|^;]"              //列出未注釋的內容

 local 10.17.1.20  #監聽地址 port 1194   #監聽端口 proto tcp   #監聽協議 dev tun   #采用路由隧道模式 ca ca.crt #ca證書路徑 cert server.crt  #服務器證書 key server.key  # This file should be kept secret 服務器密鑰 dh dh2048.pem #密鑰交換協議文件 server 10.8.0.0 255.255.255.0    #給客戶端分配地址池，注意：不能和VPN服務器內網網段有相同 ifconfig-pool-persist ipp.txt push "route 192.168.20.0 255.255.255.0" #允許客戶端訪問內網 20.0 的網段。 push"dhcp-option DNS 8.8.8.8"       #dhcp分配dns client-to-client  #客戶端之間互相通信 keepalive 10 120 #存活時間，10秒ping一次,120 如未收到響應則視為斷線 comp-lzo    #傳輸數據壓縮 max-clients 100 #最多允許 100 客戶端連接 user nobody    #用戶 group nobody   #用戶組 persist-key persist-tun status    /var/log/openvpn/openvpn-status.log log    /var/log/openvpn/openvpn.log verb 3

11.iptables配置

 清空iptables配置： iptables -F iptables -X 配置openvpn的nat功能，將所有網段的包轉發到eth0口： iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE 添加FORWARD白名單： iptables -A FORWARD -i tun+ -j ACCEPT 開啟系統的路由功能： echo "1" > /proc/sys/net/ipv4/ip_forward service iptables save        //保存iptables配置 service iptables restart      //重啟iptables

12. 啟動openvpn

 service openvpn start

13. 配置客戶端

復制客戶端配置文件client.ovpn：

 cp /usr/share/doc/openvpn-2.3.*/sample/sample-config-files/client.conf  /etc/openvpn/client.ovpn

修改客戶端配置文件：

 cat server.conf | grep "^[^#|^;]"

 client devtun prototcp  //改為tcp remote203.195.xxx.xxx1194   //OpenVPN服務器的外網IP和端口 resolv-retryinfinite nobind persist-key persist-tun caca.crt  //client1的證書 certclient.crt keyclient.key  //client1的密鑰 ns-cert-typeserver comp-lzo verb3