Access machines behind VPN

gamatos

Hello everyone,

first of all please excuse my ignorance, I'm a complete noob when it comes to networking, and maybe im trying to eat more than I can chew.

I have a raspberry pi (10.1.1.2) connected to my isp modem router (10.1.1.1) via eth0 running open vpn. I can connect remotely to the pi without any issues.
I have a UDM router (192.168.1.1) whose WAN port is connected to my isp modem router. The UDM provides wifi access to other computers.
The raspberry pi is connected to UDMs wireless network via wlan0 (192.168.1.216). From the raspberry pi i can ping machines on the 192.168.1.X network.

I want to be able to ping machines on the 192.168.1.X network from the clients connecting to the VPN.

I understand that this is possible, but I'm really getting lost in the terminology. I tried following the flowchart and could not even get past the first step.

I appreciate the time you took to read this

TinCanTech

Start here: https://community.openvpn.net/openvpn/wiki/HOWTO

gamatos

That's what I started with but i do not understand a thing. Some examples might apply in my situation but i'm not 100% sure because I dont really understands what it refers to.

I explained my problem in layman terms, can someone help me through this in layman terms as well?
No, this is not the right place for these things is also an acceptable answer.

TinCanTech

There is a section of the howto specific to your question.
https://community.openvpn.net/openvpn/wiki/HOWTO#ExpandingthescopeoftheVPNtoincludeadditionalmachinesoneithertheclientorserversubnet

gamatos

Thank you! I will try to go through it

First, you must advertise the 10.66.0.0/24 subnet to VPN clients as being accessible through the VPN. This can easily be done with the following server-side config file directive:

Does this refer to a terminal command or editing a configuration file? In my case 10.66.0.0/24 is 192.168.1.0/24 and 10.8.0.0/24 is 10.1.1.0/24 ?

Next, you must set up a route on the server-side LAN gateway to route the VPN client subnet (10.8.0.0/24) to the OpenVPN server

What would this option be called on the router?

Make sure that you've enabled IP and TUN/TAP forwarding on the OpenVPN server machine.

I already have a port forwarding setup for the ovpn port. Is this what it means? Do i need to put the raspberry on the DMZ of the router?

gamatos

First, you must advertise the 10.66.0.0/24 subnet to VPN clients as being accessible through the VPN. This can easily be done with the following server-side config file directive:

I added push "route 192.168.1.0 255.255.255.0" in my /etc/openvpn/server.conf file.

Next, you must set up a route on the server-side LAN gateway to route the VPN client subnet (10.8.0.0/24) to the OpenVPN server

still no clue how to perform this step, or what it means

Make sure that you've enabled IP and TUN/TAP forwarding on the OpenVPN server machine.

I added net.ipv4.ip_forward=1 in my /etc/sysctl.conf file. Is this sufficient?