IPSec VPN Between OPNSense and Unifi not sending traffic over tunnel

[aaronu]

While trying to establish an IPSec VPN between my opnsense router located in a data center environment to a UNIFI UDM appliance at a remote site, I have been running into some issues.

Here is some info on what is trying to be achieved and how. I am trying to establish an ipsec vpn connection between the two sites. This vpn connection is being made to a an office location utilizing a storage server on the data center (opnsense) network. The data center network has a large ip block. The ip being used for the actual opnsense unit is different that the one I want to connect the vpn to. I am essentially using a seperate ip and vlan network for all traffic connected to this remote office, as only that customers servers live on this vlan. The ip is setup as a virtual ip as an ip alias in opnsense and is showing the opnsense login when reached.



What is happening:

After setting up the vpn connection and a lot of firewall rules to route the traffic from the wan to ipsec, than ipsec to the vlan of the server, ect, I was able to get a vpn connection via ipsec, showing connection on the unifi end, and connection on the OPNsense end. I also setup the child uner the OPNsense connection for the remote and local subnets. When attempting to ping the server on the data center network from the office, I however have not gotten a ping. I noticed that in the ipsec connection status, there is no value (not even 0) is the bytes sent or received, and the child states installed, but not established. Also while attempting a ping, the live log of opnsense shows a connection attempt from the remote office ip to the vpn ip, but with no port attached to the request, not attempting over an ipsec port, and is blocking the traffic. I am hesitant to allow anything from the remote location for security. I'm honestly not sure what to do here. I have not been able to find any resources for a setup between opnsense and unifi at all and have run out of things to try.


Any help or suggestions are appreciated.

Thanks!