Ubuntu下安装xl2tpd服务

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.confecho "net.ipv4.conf.all.accept_redirects = 0" |  tee -a /etc/sysctl.confecho "net.ipv4.conf.all.send_redirects = 0" |  tee -a /etc/sysctl.confecho "net.ipv4.conf.default.rp_filter = 0" |  tee -a /etc/sysctl.confecho "net.ipv4.conf.default.accept_source_route = 0" |  tee -a /etc/sysctl.confecho "net.ipv4.conf.default.send_redirects = 0" |  tee -a /etc/sysctl.confecho "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

编辑/etc/ipsec.conf

version 2 # conforms to second version of ipsec.conf specificationconfig 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=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%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"

编辑/etc/xl2tpd/xl2tpd.conf

[global]ipsec saref = yessaref refinfo = 30;debug avp = yes;debug network = yes;debug state = yes;debug tunnel = yes[lns default]ip range = 172.16.1.30-172.16.1.100local ip = 172.16.1.1refuse pap = yesrequire authentication = yes;ppp debug = yespppoptfile = /etc/ppp/options.xl2tpdlength bit = yes

编辑/etc/ppp/options.xl2tpd

require-mschap-v2ms-dns 8.8.8.8ms-dns 8.8.4.4authmtu 1200mru 1000crtsctshide-passwordmodemname l2tpdproxyarplcp-echo-interval 30lcp-echo-failure 4

编辑/etc/ppp/chap-secrets

 Secrets for authentication using CHAP# client       server  secret                  IP addressesbob            l2tpd   DF98F09F74C06A2F             *

service ipsec restartservice xl2tpd restart