IPsec/L2TP VPN Server Auto Setup Scripts

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Scripts for automatic configuration of an IPsec/L2TP VPN server on Ubuntu 16.04/14.04/12.04, Debian 8 and CentOS 6 & 7. All you need to do is providing your own values for IPSEC_PSK, VPN_USER and VPN_PASSWORD, and let them handle the rest.

We will use Libreswan as the IPsec server, and xl2tpd as the L2TP provider.

Link to my VPN tutorial with detailed usage instructions

Table of Contents

• Author
• Features
• Requirements
• Installation
  • Ubuntu & Debian
  • CentOS & RHEL
• Next Steps
• Important Notes
• Upgrading Libreswan
• Bugs & Questions
• License

Author

Lin Song

• Final year U.S. PhD candidate seeking opportunities in the industry.
• View my LinkedIn profile and contact me: www.linkedin.com/in/linsongui

Features

• Fully automated IPsec/L2TP VPN server setup, no user input needed
• Encapsulates all VPN traffic in UDP - does not need ESP protocol
• Can be directly used as "user-data" for a new Amazon EC2 instance
• Automatically determines public IP and private IP of server
• Includes basic IPTables rules and sysctl.conf settings
• Tested with Ubuntu 16.04/14.04/12.04, Debian 8 and CentOS 6 & 7

Requirements

A newly created Amazon EC2 instance, using these AMIs: (See instructions)

• Ubuntu 16.04 (Xenial), 14.04 (Trusty) or 12.04 (Precise)
• Debian 8 (Jessie) EC2 Images
• CentOS 7 (x86_64) with Updates HVM
• CentOS 6 (x86_64) with Updates HVM

-OR-

A dedicated server or KVM/Xen-based Virtual Private Server (VPS), with the following OS:
 (Note: Starting with a freshly installed system is recommended)

• Ubuntu 16.04 (Xenial), 14.04 (Trusty) or 12.04 (Precise)
• Debian 8 (Jessie)
• Debian 7 (Wheezy) » Not recommended. Requires this workaround to work.
• CentOS / Red Hat Enterprise Linux (RHEL) 6 or 7

OpenVZ VPS users should instead try Nyr's OpenVPN script.

» I want to run my own VPN but don't have a server for that

⚠️ DO NOT run these scripts on your PC or Mac! They should only be used on a server!

Installation

Ubuntu & Debian

First, update your system with apt-get update && apt-get dist-upgrade and reboot. This is optional, but recommended.

wget https://github.com/hwdsl2/setup-ipsec-vpn/raw/master/vpnsetup.sh -O vpnsetup.sh
nano -w vpnsetup.sh
[Edit and replace IPSEC_PSK, VPN_USER and VPN_PASSWORD with your own values]
sudo sh vpnsetup.sh

CentOS & RHEL

First, update your system with yum update and reboot. This is optional, but recommended.

yum -y install wget nano
wget https://github.com/hwdsl2/setup-ipsec-vpn/raw/master/vpnsetup_centos.sh -O vpnsetup_centos.sh
nano -w vpnsetup_centos.sh
[Edit and replace IPSEC_PSK, VPN_USER and VPN_PASSWORD with your own values]
sudo sh vpnsetup_centos.sh

If unable to download via wget, you may alternatively open vpnsetup.sh (or vpnsetup_centos.sh) and click the Raw button. Press Ctrl-A to select all, Ctrl-C to copy, then paste into your favorite editor.

Next Steps

Get your computer or device to use the VPN. Search the web for instructions, e.g. google.com/search?q=setup+l2tp+client

Enjoy your very own VPN! ✨🎉🚀✨

Important Notes

For Windows users, a one-time registry change is required if the VPN server and/or client is behind NAT (e.g. home router). In case you see Error 628, go to the "Security" tab of VPN connection properties, enable CHAP and disable MS-CHAP v2.

Android 6 (Marshmallow) users: After install, edit /etc/ipsec.conf and append ,aes256-sha2_256 to both ike= and phase2alg=. Then add a new line sha2-truncbug=yes. Indent lines with two spaces. Finally, run service ipsec restart.

iPhone/iPad users: In iOS settings, choose L2TP (instead of IPSec) as the VPN type. In case you are unable to connect, edit ipsec.conf and replace rightprotoport=17/%any with rightprotoport=17/0. Then restart ipsec service.

If you wish to create multiple VPN users with different credentials, just edit a few lines in the scripts.

Clients are configured to use Google Public DNS when the VPN is active. To change, set ms-dns in options.xl2tpd.

For Amazon EC2 instances only: In the security group, open UDP ports 500 & 4500 and TCP port 22 (optional, for SSH).

If you configured a custom SSH port (not 22) or wish to allow other services, edit IPTables rules before using the scripts.

The scripts will backup your existing config files before making changes, to the same folder with .old-date-time suffix.

Upgrading Libreswan

The additional scripts vpnupgrade_Libreswan.sh and vpnupgrade_Libreswan_centos.sh can be used to periodically upgrade Libreswan to the latest version. Check the official website and update the SWAN_VER variable as necessary.

Bugs & Questions

• Got a question? Please first search other people's comments in this GitHub Gist and on my blog.
• Ask Libreswan (IPsec) related questions on the mailing list, or read these wikis: [1] [2] [3] [4] [5].
• If you found a reproducible bug, open a GitHub Issue to submit a bug report.

License

Copyright (C) 2014-2016 Lin Song   
Based on the work of Thomas Sarlandie (Copyright 2012)

This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License
Attribution required: please include my name in any derivative and let me know how you have improved it!