L2TP/IPsec RSA

chap-secrets

# Secrets for authentication using CHAP
# client	server	secret			IP addresses

username * password *

ipsec.conf

# ipsec.conf - strongSwan IPsec configuration file

config setup

conn l2tp
      left=%any
      leftprotoport=udp/l2tp
      leftid=vpn.example.com
      leftcert=vpn.example.com
      right=%any
      rightprotoport=udp/%any
      keyingtries=1
      keyexchange=ikev1
      type=transport
      auto=add

ipsec.secrets

# This file holds shared secrets or RSA private keys for authentication.

# RSA private key for this host, authenticating it to any other host
# which knows the public part.

: RSA vpn.example.com.key

options.l2tpd.lns

ms-dns 8.8.8.8
ms-dns 8.8.4.4
auth
crtscts
lock
mru 1280
mtu 1280
proxyarp
refuse-pap
refuse-chap
refuse-mschap
require-mschap-v2
noccp

xl2tpd.conf

[global]
port = 1701

[lns default]
ip range = 10.10.0.2-10.10.0.254
local ip = 10.10.0.1
length bit = yes
refuse pap = yes
refuse chap = yes
require authentication = yes
name = l2tp
pppoptfile = /etc/ppp/options.l2tpd.lns