David Cox wrote:

I have several VPN servers and 2 radius servers. I run OpenVPN, PPTP and L2TP. PPTP/L2TP will respect the simultaneous-use flag but OpenVPN does not respect the simultaneous-use flag on my primary radius server.

That's really a wrong description. Simultaneous-Use is implemented on FreeRADIUS, not OpenVPN.

It seems to work just fine if I use the failover. Here is the debug output.

Which shows one accounting packet. i.e. it's useless for telling the difference between the working and non-working systems.

The only things I can see that is different between the primary and backup is OpenVPN has caps in the primary and for some reason [detail] expand: %{Packet-Src-IP-Address} is not displayed in the primary logs. Any advice would be a huge help.

Run the server in debugging mode, and look at the packets. ALL OF THEM. Look at the authentication and accounting packets for a working session, and then compare them to the authentication and accounting packets for a non-working session. The differences will be why one works and the other doesn't. Alan DeKok.