Docker image to run an IPsec VPN server, with both IPsec/L2TP and IPsec/XAuth ("Cisco IPsec").

Based on Debian Jessie with Libreswan (IPsec VPN software) and xl2tpd (L2TP daemon).

» See also: IPsec VPN Server on Ubuntu, Debian and CentOS

Read this in other languages: English, Chinese (Simplified).

Follow these instructions to get Docker running on your Linux server.

Get the trusted build from the Docker Hub registry:

docker pull hwdsl2/ipsec-vpn-server

Alternatively, you may build from source code on GitHub.

This Docker image uses the following three environment variables, that can be declared in an env file:

VPN_IPSEC_PSK=<IPsec pre-shared key>
VPN_USER=<VPN Username>
VPN_PASSWORD=<VPN Password>

This will create a single user account for VPN login. The IPsec PSK (pre-shared key) is specified by the VPN_IPSEC_PSK environment variable. The VPN username is defined in VPN_USER, and VPN password is specified by VPN_PASSWORD.

Note 1: In your env file, DO NOT put single or double quotes around values, or add space around =. Also, DO NOT use these characters within values: \ " '.

Note 2: The same VPN account can be used by your multiple devices. However, due to an IPsec limitation, only one device behind the same NAT (e.g. home router) can connect to the VPN server at a time.

All the variables to this image are optional, which means you don't have to type in any environment variable, and you can have an IPsec VPN server out of the box! Read the sections below for details.

Important: First, load the IPsec NETKEY kernel module on the Docker host:

sudo modprobe af_key

Create a new Docker container from this image (replace ./vpn.env with your own env file):

docker run \
    --name ipsec-vpn-server \
    --env-file ./vpn.env \
    --restart=always \
    -p 500:500/udp \
    -p 4500:4500/udp \
    -v /lib/modules:/lib/modules:ro \
    -d --privileged \
    hwdsl2/ipsec-vpn-server

If you did not specify an env file in the docker run command above, VPN_USER will default to vpnuser and both VPN_IPSEC_PSK and VPN_PASSWORD will be randomly generated. To retrieve them, view the container logs:

docker logs ipsec-vpn-server

Search for these lines in the output:

Connect to your new VPN with these details:

Server IP: <VPN Server IP>
IPsec PSK: <IPsec pre-shared key>
Username: <VPN Username>
Password: <VPN Password>

(Optional) Backup the generated VPN credentials (if any) to the current directory:

docker cp ipsec-vpn-server:/opt/src/vpn-gen.env ./

To check the status of your IPsec VPN server, you can pass ipsec status to your container like this:

docker exec -it ipsec-vpn-server ipsec status

Get your computer or device to use the VPN. Please refer to:

Configure IPsec/L2TP VPN Clients
Configure IPsec/XAuth ("Cisco IPsec") VPN Clients

If you get an error when trying to connect, see Troubleshooting.

Enjoy your very own VPN!

There are two services running: Libreswan (pluto) for the IPsec VPN, and xl2tpd for L2TP support.

Clients are configured to use Google Public DNS when the VPN connection is active.

The default IPsec configuration supports:

• IKEv1 with PSK and XAuth ("Cisco IPsec")
• IPsec/L2TP with PSK

The ports that are exposed for this container to work are:

• 4500/udp and 500/udp for IPsec

Advanced users can download and compile the source code from GitHub:

git clone https://github.com/hwdsl2/docker-ipsec-vpn-server.git
cd docker-ipsec-vpn-server
docker build -t hwdsl2/ipsec-vpn-server .

or use this if not modifying the source code:

docker build -t hwdsl2/ipsec-vpn-server github.com/hwdsl2/docker-ipsec-vpn-server.git

To start a Bash session in the running container:

docker exec -it ipsec-vpn-server env TERM=xterm bash -l

• IPsec VPN Server on Ubuntu, Debian and CentOS
• IKEv2 VPN Server on Docker

Copyright (C) 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!