A tiny Alpine based docker image to quickly setup an L2TP over IPsec VPN client w/ PSK.
Does your office or a client have a VPN server already setup and you just need to connect to it? Do you use Linux and are jealous that the one thing a MAC can do better is quickly setup this kind of VPN? Then here is all you need:
- VPN Server Address
- Pre Shared Key
- Username
- Password
Setup environment variables for your credentials and config:
export VPN_SERVER_IPV4='1.2.3.4'
export VPN_PSK='my pre shared key'
export VPN_USERNAME='[email protected]'
export VPN_PASSWORD='mypass'
export VPN_PASSWORD='mypass'
export VPN_TUNNEL_ROUTE_NETWORK_1=10.10.10.0/24 # automatically add a route to forward all traffic for 10.10.10.0/24 network via VPN
Now run it (you can daemonize of course after debugging):
docker run --rm -it --privileged --net=host \
-v /lib/modules:/lib/modules:ro \
-e VPN_SERVER_IPV4 \
-e VPN_PSK \
-e VPN_USERNAME \
-e VPN_PASSWORD \
-e VPN_TUNNEL_ROUTE_NETWORK_1 \
sjnet/l2tp-ipsec-vpn-client
From the host machine configure traffic to route through VPN link:
# confirm the ppp0 link and get the peer e.g. (192.0.2.1) IPV4 address
ip a show ppp0
# route traffic for a specific target ip through VPN tunnel address
sudo ip route add 1.2.3.4 via 192.0.2.1 dev ppp0
# route all traffice through VPN tunnel address
sudo ip route add default via 192.0.2.1 dev ppp0
# or
sudo route add -net default gw 192.0.2.1 dev ppp0
# and delete old default routes e.g.
sudo route del -net default gw 10.0.1.1 dev eth0
# when your done add your normal routes and delete the VPN routes
# or just `docker stop` and you'll probably be okay
On your VPN client localhost machine you may need to sudo modprobe af_key
if you're getting this error when starting:
pluto[17]: No XFRM/NETKEY kernel interface detected
pluto[17]: seccomp security for crypto helper not supported