SOLVED OpenVPN (tun mode) via OPNsense working, but no access to TrueNAS via VPN

[socrates324]

Hi!

So I have a problem I've been pulling my hair out trying to figure it out.

I had an IPSec VPN running between my ISP's router (AVM Fritzbox) and my iPhone.

Now after my FTTH was installed, I decided to switch to OPNsense with OpenVPN (tun) instead of the ISP-router solution amongst other things for better VPN performance.

The OpenVPN is running, I can access EVERY host on my home network trough VPN but my TrueNAS installation. No access to services, no access to WebUI not even PING is working.

The ISP Router (Fritzbox) is still configured as the default gateway, but there is a static route in place on Fritzbox to redirect traffic with destination VPN to the OPNsense box.

Local IPv4 configuration with default gateway set to Fritzbox is present on TrueNAS. I even temporarily added a static route on the TrueNAS explicitly for the VPN traffic but that also did not help.

My configuration:

OPNsense:
---------------
OPNsense 22.7.4-amd64
FreeBSD 13.1-RELEASE-p2
OpenSSL 1.1.1q 5 Jul 2022

TrueNAS:
-----------
TrueNAS 12.0-U8.1


Any ideas what I might be missing?

Any hints/pointers would be greatly appreciated!

Cheers,
Soc

 

[socrates324]

Ok, so I knew it had to be something stupid. I just didn't know if it was stupid on the OPNsense side or the TrueNAS side. I tended towards the TrueNAS side because it was the only device with problems.

Well, the stupid thing actually was that I had a static DHCP lease for my TrueNAS still configured on my OPNsense box. I ran into the "Realtek NIC problem" and added an Intel NIC on my TrueNAS server in order to finally solve the problem.

But as the OPNsense box still had the MAC address of the previous Realtek NIC from the static lease, it used that MAC when communicating with TrueNAS. And that, of course, wouldn't work.

Maybe this will help someone else to save some time...

Cheers,
Soc