L2TP

Installation

apt-get install  xl2tpd ppp openswan

Openswan

cat /etc/ipsec.conf
version 2.0
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
   authby=secret
   pfs=no
   auto=add
   type=transport
   left=XXX.XXX.XXX.XXX
   leftprotoport=17/1701
   right=%any
   rightprotoport=17/%any

cat /etc/ipsec.secrets 
XXX.XXX.XXX.XXX  %any : PSK "1234"

XL2TP

cat /etc/xl2tpd/xl2tpd.conf 

[global]
ipsec saref = yes

[lns default]
ip range = 10.1.2.2-10.1.2.255
local ip = 10.1.2.1
refuse chap = yes
refuse pap = yes
require authentication = yes
ppp debug = yes
pppoptfile = /etc/ppp/options.xl2tpd
length bit = yes

PPP

cat /etc/ppp/options.xl2tpd

require-mschap-v2
ms-dns 192.168.240.21
ms-dns 192.168.240.22
asyncmap 0
auth
crtscts
lock
hide-password
modem
debug
name l2tpd
proxyarp
lcp-echo-interval 30
lcp-echo-failure 4

cat /etc/ppp/chap-secrets 

xinux        l2tpd       "geheimes-passwort"	       *
l2tpd        xinux	  "geheimes-passwort"	       *

~ ~ ~

Quellen:

• http://blog.riobard.com/2010/04/30/l2tp-over-ipsec-ubuntu
• http://pleasefeedthegeek.wordpress.com/2012/04/21/l2tp-ubuntu-server-setup-for-ios-clients/