Wireless Joint

So, I connected the CBA850 via port 2 and POE to an unmanaged POE switch (that provides the power to the device). It powers up and connects to the internet. I then put an access point (just a Wi-Fi access point) to the same unmanaged switch and the CBA850 doesn't seem to give the access point an IP address and therefore allow clients access. Clients wont get DHCP either.

If I connect the access point via port 1 (and power the CBA850 with the adapter) the DHCP seems to work, and clients get addresses.

I am curious because I really wanted to power this with POE, so I am not sure what I am missing? Forgive me if this is dumb question. It looks to me as though port 2 would be configured for DHCP server?

That is most likely due to the CBA850LP6 being in IP Passthrough mode. It does this automatically when using the PoE LAN port. There are instructions on this TUTORIAL on how to configure it to be in DHCP mode.

Either what JimHelms has suggested, or it's possible that the unmanaged POE hub in between the CBA850LP6 and your access point is causing CBA850LP6 not to assign DHCP properly. For testing purposes try to borrow a managed switch from someone and see if you get DHCP IP with that.