免费vpn教程之L2TP ipsec vpn搭建

前面一篇本博客已经提到--OpenVZ VPS怎样搭建PPTP VPN

今天在这里给大家介绍下l2tp ipsec vpn的搭建教程。下面说下我们需要的一些载体：

运行环境:centos 5.7 32bit【redhat系都可以用】

1、首先安装必要的包。

yum install -y ppp iptables make gcc gmp-devel xmlto bison flex xmlto libpcap-devel lsof vim-enhanced

2、下载安装openswan.

wget http://www.openswan.org/download/openswan-2.6.24.tar.gztar zxvf openswan-2.6.24.tar.gz  cd openswan-2.6.24  make programs install

3、安装xl2tpd。[这里可能有的筒子们用的编译的，不过安装扩展源之后直接安装岂不是更方便]

rpm -ivh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm   [centos 5x]  rpm -ivh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-7.noarch.rpm   [centos 6x]  

yum install xl2tpd

4、各种修改配置文件了。编辑 /etc/ipsec.conf 注意$vpsip替换成你机器的ip，贴出配置文件，大家修改就好了。

config setup      nat_traversal=yes      virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12      oe=off      protostack=netkey     conn L2TP-PSK-NAT      rightsubnet=vhost:%priv      also=L2TP-PSK-noNAT     conn L2TP-PSK-noNAT      authby=secret      pfs=no      auto=add      keyingtries=3      rekey=no      ikelifetime=8h      keylife=1h      type=transport      left=$vpsip      leftprotoport=17/1701      right=%any      rightprotoport=17/%any

5、编辑 /etc/ipsec.secrets注意$vpsip替换成你机器的ip, $psk缓存你想设置的密钥

$vpsip %any: PSK "$psk"

6、修改/etc/sysctl.conf，添加转发补丁等功能。注意这里的你参照你文件内容的改，没有的添加。

net.ipv4.ip_forward = 1  net.ipv4.conf.default.rp_filter = 0  net.ipv4.conf.all.send_redirects = 0  net.ipv4.conf.default.send_redirects = 0  net.ipv4.conf.all.log_martians = 0  net.ipv4.conf.default.log_martians = 0  net.ipv4.conf.default.accept_source_route = 0  net.ipv4.conf.all.accept_redirects = 0  net.ipv4.conf.default.accept_redirects = 0  net.ipv4.icmp_ignore_bogus_error_responses = 1

7、修改完成后，运行如下命令使之生效。

sysctl -p

8、验证ipsec运行。

ipsec setup restart  ipsec verify

输出以下内容就表示配置成功了

Checking your system to see if IPsec got installed and started correctly:  Version check and ipsec on-path                             	[OK]  Linux Openswan U2.6.24/K2.6.32.16-linode28 (netkey)  Checking for IPsec support in kernel                        	[OK]  NETKEY detected, testing for disabled ICMP send_redirects   	[OK]  NETKEY detected, testing for disabled ICMP accept_redirects 	[OK]  Checking for RSA private key (/etc/ipsec.secrets)           	[OK]  Checking that pluto is running                              	[OK]  Pluto listening for IKE on udp 500                          	[OK]  Pluto listening for NAT-T on udp 4500                       	[OK]  Two or more interfaces found, checking IP forwarding        	[OK]  Checking NAT and MASQUERADEing  Checking for 'ip' command                                   	[OK]  Checking for 'iptables' command                             	[OK]  Opportunistic Encryption Support                            	[DISABLED]

9、编辑 /etc/xl2tpd/xl2tpd.conf

[global]  ipsec saref = yes  listen-addr = $vpsip  [lns default]  ip range = 10.1.88.2-10.1.88.254      local ip = 10.1.88.1       refuse chap = yes  refuse pap = yes  require authentication = yes  ppp debug = yes  pppoptfile = /etc/ppp/options.xl2tpd  length bit = yes

10、编辑 /etc/ppp/options.xl2tpd

require-mschap-v2  ms-dns 208.67.222.222  ms-dns 208.67.220.220  asyncmap 0  auth  crtscts  lock  hide-password  modem  debug  name l2tpd  proxyarp  lcp-echo-interval 30  lcp-echo-failure 4

11、设置用户名,密码:编辑 /etc/ppp/chap-secrets

# user server password ip  username * userpass * #改成你的用户名 密码

12、重启xl2tpd

service xl2tpd restart

13、设置iptables。

iptables --table nat --append POSTROUTING --jump MASQUERADE

service iptables save  service iptables restart

chkconfig xl2tpd on  chkconfig iptables on  chkconfig ipsec on

好吧，搭建完成，现在测试一下吧，有条件的筒子们可以把有限的资源提供给无尽的网络，提供免费vpn哦，如果有任何配置上的问题，可以联系我，我们共同研究！

原文：http://www.seevpn.com/article-127.html