apt-get install openswan xl2tpd ppp lsof iptables -t nat -A POSTROUTING -j SNAT --to-source <IP地址> -o eth0 echo "net.ipv4.ip_forward = 1" | tee -a /etc/sysctl.conf echo "net.ipv4.conf.all.accept_redirects = 0" | tee -a /etc/sysctl.conf echo "net.ipv4.conf.all.send_redirects = 0" | tee -a /etc/sysctl.conf echo "net.ipv4.conf.default.rp_filter = 0" | tee -a /etc/sysctl.conf echo "net.ipv4.conf.default.accept_source_route = 0" | tee -a /etc/sysctl.conf echo "net.ipv4.conf.default.send_redirects = 0" | tee -a /etc/sysctl.conf echo "net.ipv4.icmp_ignore_bogus_error_responses = 1" | tee -a /etc/sysctl.conf for vpn in /PRoc/sys/net/ipv4/conf/*; do echo 0 > $vpn/accept_redirects; echo 0 > $vpn/send_redirects; done sysctl -p


version 2 # conforms to second version of ipsec.conf specification config setup dumpdir=/var/run/pluto/ #in what directory should things started by setup (notably the Pluto daemon) be allowed to dump core? nat_traversal=yes #whether to accept/offer to support NAT (NAPT, also known as "IP Masqurade") workaround for IPsec virtual_private=%v4:,%v4:,%v4:,%v6:fd00::/8,%v6:fe80::/10 #contains the networks that are allowed as subnet= for the remote client. In other Words, the address ranges that may live behind a NAT router through which a client connects. protostack=netkey #decide which protocol stack is going to be used. force_keepalive=yes keep_alive=60 # Send a keep-alive packet every 60 seconds. conn L2TP-PSK-noNAT authby=secret #shared secret. Use rsasig for certificates. pfs=no #Disable pfs auto=add #the ipsec tunnel should be started and routes created when the ipsec daemon itself starts. keyingtries=3 #Only negotiate a conn. 3 times. ikelifetime=8h keylife=1h ike=aes256-sha1,aes128-sha1,3des-sha1 phase2alg=aes256-sha1,aes128-sha1,3des-sha1 # https://lists.openswan.org/pipermail/users/2014-April/022947.html # specifies the phase 1 encryption scheme, the hashing algorithm, and the diffie-hellman group. The modp1024 is for Diffie-Hellman 2. Why 'modp' instead of dh? DH2 is a 1028 bit encryption algorithm that modulo's a prime number, e.g. modp1028. See RFC 5114 for details or the wiki page on diffie hellmann, if interested. type=transport #because we use l2tp as tunnel protocol left=服务器IP地址 #fill in server IP above leftprotoport=17/1701 right=%any rightprotoport=17/%any dpddelay=10 # Dead Peer Dectection (RFC 3706) keepalives delay dpdtimeout=20 # length of time (in seconds) we will idle without hearing either an R_U_THERE poll from our peer, or an R_U_THERE_ACK reply. dpdaction=clear # When a DPD enabled peer is declared dead, what action should be taken. clear means the eroute and SA with both be cleared.

编辑 /etc/ipsec.secrets 添加一行

IP地址 %any: PSK "secure_password"


[global] ipsec saref = yes saref refinfo = 30 ;debug avp = yes ;debug network = yes ;debug state = yes ;debug tunnel = yes [lns default] ip range = local ip = refuse pap = yes require authentication = yes ;ppp debug = yes pppoptfile = /etc/ppp/options.xl2tpd length bit = yes


require-mschap-v2 ms-dns ms-dns auth mtu 1200 mru 1000 crtscts hide-password modem name l2tpd proxyarp lcp-echo-interval 30 lcp-echo-failure 4


Secrets for authentication using CHAP # client server secret IP addresses bob l2tpd DF98F09F74C06A2F * service ipsec restart service xl2tpd restart