Centos 6 L*2tp 配置实例

如何科学地使用互联网，一直是个蛋疼的问题。以前使用p*ptp，iOS 10之后p*ptp被苹果干了，用不了，说是安全性不好，简直有病，我的使用环境又没有那么高的安全要求。而s*ock的使用需要在客户端安装第三方客户端才行，iOS市场上好多s*ock客户端都被下架了，剩余一些不支持自定义配置的，或者是收费的，切换iOS市场可以找到一些可用的，可恶的是切换市场的时候Apple要求一定要提交信用卡等信息。现在只能改用L*2tp协议，本文讲述其在CentOS 6的配置方法，在CentOS 7应该也差不多，我没有实际尝试。

1.安装一堆乱七八糟的环境包

yum install -y make gcc gmp-devel xmlto bison flex xmlto libpcap-devel lsof vim-enhanced man policycoreutil

2.安装openswan，ppp等

yum install openswan ppp xl2tpd

注意，以上openswan，xl2tpd如果找不到yum源，则需自行添加yum源，也可以直接wget下载后安装，具体如下：
a.openswan

wget https://download.openswan.org/openswan/old/openswan-2.6/openswan-2.6.38.tar.gz  tar -zxvf openswan-2.6.38.tar.gz  cd openswan-2.6.38  make programs install  

b.xl2tpd

wget https://download.openswan.org/xl2tpd/xl2tpd-1.3.0.tar.gz  tar zxf xl2tpd-1.3.0.tar.gz  cd xl2tpd-1.3.0  make && make install 

c.rp-l2tp，xl2tpd是新版的话，这玩意可以不安装。

wget http://sourceforge.net/projects/rp-l2tp/files/rp-l2tp/0.4/rp-l2tp-0.4.tar.gz  tar -zxvf rp-l2tp-0.4.tar.gz  cd rp-l2tp-0.4  ./configuremake  cp handlers/l2tp-control /usr/local/sbin/  mkdir /var/run/xl2tpd/  ln -s /usr/local/sbin/l2tp-control /var/run/xl2tpd/l2tp-control  

3.修改/etc/ipsec.conf内容如下：

# /etc/ipsec.conf - Openswan IPsec configuration file# This file:  /usr/local/share/doc/openswan/ipsec.conf-sample## Manual:     ipsec.conf.5version 2.0     # conforms to second version of ipsec.conf specification# basic configurationconfig setup        # Do not set debug options to debug configuration issues!        # plutodebug / klipsdebug = "all", "none" or a combation from below:        # "raw crypt parsing emitting control klips pfkey natt x509 dpd private"        # eg:        # plutodebug="control parsing"        # Again: only enable plutodebug or klipsdebug when asked by a developer        #        # enable to get logs per-peer        # plutoopts="--perpeerlog"        #        # Enable core dumps (might require system changes, like ulimit -C)        # This is required for abrtd to work properly        # Note: incorrect SElinux policies might prevent pluto writing the core        dumpdir=/var/run/pluto/        #        # NAT-TRAVERSAL support, see README.NAT-Traversal        nat_traversal=yes        # exclude networks used on server side by adding %v4:!a.b.c.0/24        # It seems that T-Mobile in the US and Rogers/Fido in Canada are        # using 25/8 as "private" address space on their 3G network.        # This range has not been announced via BGP (at least upto 2010-12-21)        virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:25.0.0.0/8,%v6:fd00::/8,%v6:fe80::/10        # OE is now off by default. Uncomment and change to on, to enable.        oe=off        # which IPsec stack to use. auto will try netkey, then klips then mast        protostack=netkey        #这里如果是auto，改为netkey        # Use this to log to a file, or disable logging on embedded systems (like openwrt)        #plutostderrlog=/dev/null# Add connections here# sample V*PN connection# for more examples, see /etc/ipsec.d/examples/#conn sample#               # Left security gateway, subnet behind it, nexthop toward right.#               left=10.0.0.1#               leftsubnet=172.16.0.0/24#               leftnexthop=10.22.33.44#               # Right security gateway, subnet behind it, nexthop toward left.#               right=10.12.12.1#               rightsubnet=192.168.0.0/24#               rightnexthop=10.101.102.103#               # To authorize this connection, but not actually start it,#               # at startup, uncomment this.#               #auto=add#以下为新增内容conn L2TP-PSK-NAT    rightsubnet=vhost:%priv    also=L2TP-PSK-noNATconn L2TP-PSK-noNAT    authby=secret    pfs=no    auto=add    keyingtries=3    rekey=no    ikelifetime=8h    keylife=1h    type=transport    left=103.74.195.xx #这里配置服务器公网IP    leftprotoport=17/1701 #服务端口    right=%any    rightprotoport=17/%any    dpddelay=40    dpdtimeout=130    dpdaction=clear    leftnexthop=%defaultroute    rightnexthop=%defaultroute

4.配置网络转发等，修改/etc/sysctl.conf内容如下：

# Kernel sysctl configuration file for Red Hat Linux## For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and# sysctl.conf(5) for more details.# Controls IP packet forwardingnet.ipv4.ip_forward = 1 #0改为1# Controls source route verificationnet.ipv4.conf.default.rp_filter = 0 #1改为0# Do not accept source routingnet.ipv4.conf.default.accept_source_route = 0# Controls the System Request debugging functionality of the kernelkernel.sysrq = 0# Controls whether core dumps will append the PID to the core filename.# Useful for debugging multi-threaded applications.kernel.core_uses_pid = 1# Controls the use of TCP syncookies#net.ipv4.tcp_syncookies = 1# Disable netfilter on bridges.#net.bridge.bridge-nf-call-ip6tables = 0#net.bridge.bridge-nf-call-iptables = 0#net.bridge.bridge-nf-call-arptables = 0# Controls the default maxmimum size of a mesage queuekernel.msgmnb = 65536# Controls the maximum size of a message, in byteskernel.msgmax = 65536# Controls the maximum shared segment size, in byteskernel.shmmax = 68719476736# Controls the maximum number of shared memory segments, in pageskernel.shmall = 4294967296#以下为新增内容net.ipv4.conf.all.send_redirects = 0net.ipv4.conf.default.send_redirects = 0net.ipv4.conf.all.log_martians = 0net.ipv4.conf.default.log_martians = 0net.ipv4.conf.all.accept_redirects = 0net.ipv4.conf.default.accept_redirects = 0net.ipv4.icmp_ignore_bogus_error_responses = 1

执行以下命令令配置生效：

sysctl -p

5.配置l*2tp网络参数，修改/etc/xl2tpd/xl2tpd.conf内容如下：

[global]ipsec saref = yeslisten-addr = 103.74.195.xx #公网IP[lns default]ip range = 192.168.1.2-192.168.1.100 #l*2tp内网客户端IP端local ip = 192.168.1.1 #l*2tp内网本地IPrefuse chap = yesrefuse pap = yesrequire authentication = yesppp debug = yespppoptfile = /etc/ppp/options.xl2tpdlength bit = yes

修改/etc/ppp/options.xl2tpd内容如下：

ms-dns 8.8.8.8  ms-dns 8.8.4.4  asyncmap 0  auth  crtscts  lock  hide-password  modem  debug  name l2tpd  proxyarp  lcp-echo-interval 30  lcp-echo-failure 4 require-mschap-v2

6.配置客户端预共享密码，编辑/etc/ipsec.secrets内容如下：

include /etc/ipsec.d/*.secrets103.74.195.xx %any: PSK "password"

password为预共享密钥。

7.配置客户端用户名和密码，修改/etc/ppp/chap-secrets内容如下：

dancen l2tpd password *

dancen是用户名，password是密码。

8.验证ipsec运行状态

ipsec restartipsec verify

显示如下说明运行正常：

Verifying installed system and configuration filesVersion check and ipsec on-path                   [OK]Libreswan 3.15 (netkey) on 2.6.32-504.12.2.el6.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]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]

9.修改防火墙配置：

开放l*2tp对外网的访问，增加iptables的nat表规则：

iptables -t nat -A POSTROUTING -o eth1 -s 192.168.1.0/24 -j MASQUERADE #eth1为公网网卡iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -o eth0 -j MASQUERADE #eth0为私网网卡

开放udp协议的1701，500，4500端口，开放l*2tp内网forward，增加iptables的filter表规则：

iptables -t filter -A INPUT -p udp -m state --state NEW -m udp --dport 1701 -j ACCEPTiptables -t filter -A INPUT -p udp -m state --state NEW -m udp --dport 500 -j ACCEPTiptables -t filter -A INPUT -p udp -m state --state NEW -m udp --dport 4500 -j ACCEPTiptables -I FORWARD -s 192.168.1.0/24 -j ACCEPTiptables -I FORWARD -d 192.168.1.0/24 -j ACCEPT

执行

service iptables save

或

iptables-save

保存防火墙配置
执行

service iptables restart

重启防火墙

也可以直接修改防火墙配置/etc/sysconfig/iptables的内容如下：

# sample configuration for iptables service# you can edit this manually or use system-config-firewall# please do not ask us to add additional ports/services to this default configuration*filter:INPUT DROP [0:0]:FORWARD ACCEPT [0:0]:OUTPUT ACCEPT [0:0]-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT-A INPUT -p icmp -j ACCEPT-A INPUT -i lo -j ACCEPT-A INPUT -p udp -m state --state NEW -m udp --dport 1701 -j ACCEPT-A INPUT -p udp -m state --state NEW -m udp --dport 500 -j ACCEPT-A INPUT -p udp -m state --state NEW -m udp --dport 4500 -j ACCEPT-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT-A FORWARD -d 192.168.1.0/24 -j ACCEPT-A FORWARD -s 192.168.1.0/24 -j ACCEPTCOMMIT*nat-A POSTROUTING -o eth1 -s 192.168.1.0/24 -j MASQUERADE-A POSTROUTING -s 192.168.1.0/24 -o eth0 -j MASQUERADECOMMIT

10.重启xl2tp

service xl2tpd restart

没有配置服务的话，直接执行

xl2tp

运行即可。

11.添加自启动，需要把xl2tpd配置为服务：

chkconfig xl2tpd onchkconfig iptables onchkconfig ipsec on

12.客户端选择l*2tp协议，提交预共享密码以及用户名可密码即可建立连接，完毕。