OpenVPN to LAN

thepfy

Morning All.

I'm not totally new to using OpenVPN but I am not what I would call experienced with it. (I have it running on my VPS for when I have no choice but to use open WiFi), But I am unsure how I would go about putting a new VPN server in for a particular task so I figured I would consult the mighty knowledge of the community before I even start installing anything.

I want to put an openVPN server (either on a virtual box VM as it will only be for me or on something like an odroid U3) onto my home network and be able to use that for web traffic and RDP to my machines while I am out and around (Say at uni) via VPN.

I have a standard 192.168.1.1 255.255.255.0 network, the VPN server will only have 1 nic as I only have one network and will have an address statically assigned from the 192.168.1.X network (When I have done this in the past I have had more than one network so I would just route one to the other and that was enough and it was Cisco stuff not openVPN) so I guess my first question is, is it possible to have just the one network that the openVPN server is on and have the openVPN server pass traffic to the main network it also lives on? How would I go about configuring this? Get the openVPN server to hand out its own DHCP range and use iptables to route it to the main network or something else?

I hope my question has made sense, if not I am truly sorry.

Traffic

What you have described is a typical home network VPN setup and more or less exactly what I have ..

Yes you can run an openVPN server with only one LAN NIC and no WAN NIC.
Packets sent over the VPN effectively see the eth as WAN and tun as LAN ..

The network path is (and vice-versa):

From client:
- packet is created and sent out via tun
  packet is encrypted
  packet is routed via eth to the internet
To server:
- packet arrives on eth
  packet is decrypted
  packet arrives at server LAN via tun

Be aware, using a server with VirtualBox does have issues when you share the server vbox-host eth with server vbox-guest virtual nic.
It will run but you will get many replay errors.

Also, avoid 192.168.0.0/24 & 192.168.1.0/24 as your server LAN at all costs !

Start with the HOWTO:
HOWTO: For OpenVPN Community Edition