OpenVPN Question - IPV4 Tunnel and Local Network - Required to already exist or?

Networking & Firewalls
1

Hi Everyone -

Somewhat of a n00bish question here, so pleas bear with me.

In Tom’s video about setting up OpenVPN on pfSense (around the 5:53 mark of this video https://youtu.be/I61t7aoGC2Q?si=qt5LcMuT5RHl11Wb&t=354) he outlines the IPV4 Tunnel and Local Network settings, however as I am never (likely) going to share resources out (and if I do - I will use an already existing VLAN/DHCP scope) I am curious…

Do these networks need to be configured in other locations (DHCP, VLAN interfaces, etc.) prior to running the OpenVPN wizard or if I put something in there (like a 172.16.x.x) will pfSense automagically do everything required to utilize the scope I drop in?

Thanks for your time in advance.

V/R,
crix0r

2

The tunnel networks should not overlap with an existing networks that area assigned to interfaces on your system.

3

Noted, and thank you!

4

Are you using TUN (routed) or TAP (bridged) connection?

If you are using a routed VPN, it will show up as another IP interface on your devices, so it will follow the routing rules you setup, so you will want to setup the IP information in your OpenVPN config.

If you are using a bridged (TAP) interface, you don’t need to setup IP information (you still can if you want the interface to have an IP address and use routing rules instead of bridging, just using Ethernet transport over the tunnel). You can bridge at L2 so it will share DHCP and such over the VPN link - although I wouldn’t do that for large networks, the broadcast traffic will take up it bit of tunnel capacity.