CentOS7怎么部署L2TP

l2tp是一种工业标准的Internet隧道协议，功能大致和PPTP协议类似，比如同样可以对网络数据流进行加密。为众多公司所接受，已经成为IETF有关2层通道协议的工业标准，此协议基于微软的点对点隧道协议(PPTP)和思科2层转发协议(L2F)之上，这种虚拟私有网络可以被因特网服务提供商和公司通过因特网使用。

1.先看看你的主机是否支持pptp，返回结果为yes就表示通过

modprobe ppp-compress-18 && echo yes

2.是否开启了TUN

有的虚拟机主机需要开启，返回结果为cat: /dev/net/tun: File descriptor in bad state。就表示通过。

cat /dev/net/tun

3.更新一下再安装

yum install updateyum update -y

4.安装EPEL源

yum install -y epel-release

5.安装xl2tpd和libreswan

yum install -y xl2tpd libreswan lsof

6.编辑xl2tpd配置文件

vim /etc/xl2tpd/xl2tpd.conf

修改内容如下：

[global][lns default]ip range = 172.100.1.100-172.100.1.150   #分配给客户端的地址池local ip = 172.100.1.1require chap = yesrefuse pap = yesrequire authentication = yesname = LinuxVPNserverppp debug = yespppoptfile = /etc/ppp/options.xl2tpdlength bit = yes

7.编辑pppoptfile文件

vim /etc/ppp/options.xl2tpd

修改内容如下：

ipcp-accept-localipcp-accept-remotems-dns  8.8.8.8ms-dns 209.244.0.3ms-dns 208.67.222.222name xl2tpd#noccpauthcrtsctsidle 1800mtu 1410         #第一次配置不建议设置mtu，mru，否则可能789错误mru 1410nodefaultroutedebuglockproxyarpconnect-delay 5000refuse-paprefuse-chaprefuse-mschaprequire-mschap-v2persistlogfile /var/log/xl2tpd.log

8.编辑ipsec配置文件

vim /etc/ipsec.confconfig setup       protostack=netkey       dumpdir=/var/run/pluto/       virtual_private=%v4:10.0.0.0/8,%v4:172.100.0.0/12,%v4:25.0.0.0/8,%v4:100.64.0.0/10,%v6:fd00::/8,%v6:fe80::/10       include /etc/ipsec.d/*.conf

9.编辑include的conn文件

vim /etc/ipsec.d/l2tp-ipsec.conf

修改内容如下：

conn L2TP-PSK-NAT   rightsubnet=0.0.0.0/0   dpddelay=10   dpdtimeout=20   dpdaction=clear   forceencaps=yes   also=L2TP-PSK-noNATconn L2TP-PSK-noNAT   authby=secret   pfs=no   auto=add   keyingtries=3   rekey=no   ikelifetime=8h   keylife=1h   type=transport   left=192.168.0.17   #service/VPS的外网地址，某些vps只有eth0一块网卡的，                       #就填内网地址，内核开启nat转发就可以了，                       #CentOS7以下的用iptables定义转发规则   leftprotoport=17/1701   right=%any   rightprotoport=17/%any

10.设置用户名密码

vim /etc/ppp/chap-secrets

修改内容：

vpnuser * pass *说明：用户名[空格]service[空格]密码[空格]指定IP

11.设置PSK

vim /etc/ipsec.d/default.secrets: PSK "testvpn"

12.CentOS7防火墙设置

firewall-cmd --permanent --add-service=ipsecfirewall-cmd --permanent --add-port=1701/udpfirewall-cmd --permanent --add-port=4500/udpfirewall-cmd --permanent --add-masqueradefirewall-cmd --reload

13.IP_FORWARD 设置

vim /etc/sysctl.d/60-sysctl_ipsec.confnet.ipv4.ip_forward = 1net.ipv4.conf.all.accept_redirects = 0net.ipv4.conf.all.rp_filter = 0net.ipv4.conf.all.send_redirects = 0net.ipv4.conf.default.accept_redirects = 0net.ipv4.conf.default.rp_filter = 0net.ipv4.conf.default.send_redirects = 0net.ipv4.conf.eth0.accept_redirects = 0net.ipv4.conf.eth0.rp_filter = 0net.ipv4.conf.eth0.send_redirects = 0net.ipv4.conf.eth2.accept_redirects = 0net.ipv4.conf.eth2.rp_filter = 0net.ipv4.conf.eth2.send_redirects = 0net.ipv4.conf.eth3.accept_redirects = 0net.ipv4.conf.eth3.rp_filter = 0net.ipv4.conf.eth3.send_redirects = 0net.ipv4.conf.ip_vti0.accept_redirects = 0net.ipv4.conf.ip_vti0.rp_filter = 0net.ipv4.conf.ip_vti0.send_redirects = 0net.ipv4.conf.lo.accept_redirects = 0net.ipv4.conf.lo.rp_filter = 0net.ipv4.conf.lo.send_redirects = 0net.ipv4.conf.ppp0.accept_redirects = 0net.ipv4.conf.ppp0.rp_filter = 0net.ipv4.conf.ppp0.send_redirects = 0

重启生效

systemctl restart network

13.ipsec启动&检查

systemctl enable ipsecsystemctl restart ipsec

检查：ipsec verify

正常输出：

Verifying installed system and configuration filesVersion check and ipsec on-path                         [OK]Libreswan 3.15 (netkey) on 3.10.0-123.13.2.el7.x86_64Checking for IPsec support in kernel                    [OK]NETKEY: Testing XFRM related proc values        ICMP default/send_redirects                    [OK]        ICMP default/accept_redirects                  [OK]        XFRM larval drop                               [OK]Pluto ipsec.conf syntax                                 [OK]Hardware random device                                  [N/A]Two or more interfaces found, checking IP forwarding    [OK]Checking rp_filter                                      [OK]Checking that pluto is running                          [OK]Pluto listening for IKE on udp 500                     [OK]Pluto listening for IKE/NAT-T on udp 4500              [OK]Pluto ipsec.secret syntax                              [OK]Checking 'ip' command                                   [OK]Checking 'iptables' command                             [OK]Checking 'prelink' command does not interfere with FIPSChecking for obsolete ipsec.conf options             [OK]Opportunistic Encryption                                [DISABLED]

14.xl2tpd启动

systemctl enable xl2tpdsystemctl restart xl2tpd

15.Windows连接

Windows连接，需要修改注册表键值（据说可以不用修改，但是我的不修改的话，一直789，log无显示）