Bridge with DHCP client

[mauro]

Dea rall,
I'm new to opnsense and I'm happy I decided to start to use it.

I have an APU2D4 (3 NICs) and for fun few years back I built my own 'IT' corner with a NAS and a webserver.

Thi IT corner is so configured:

• modem/router with openwrt generating a DMZ network for which is the DHCP server (old setup on which I have to work on but I'm never home long enough to have direct access to my devices
• Zeroshell as FW in the DMZ with DHCP (Client) and a bridge of the 3 NICs working also as switch
• webserver and NAS

Now I'm trying to change Zeroshell with OPNsense and I got stucked right at the beginning. First step is to replicate the Bridge in OPNSense using the DHCP server from the router/modem.

I followed the documentation about how to create a bridge assigning to it the LAN specs which did work.

After I assgned the LAN itnerface to the original NIC, created a new BRIDGE interface with dymanic DHCP. When I connect the BRIDGE to the router, the interface receive an IP accordingly but:

• if I connect my pc to BRIDGE I don't receive the IP
• despite I set up a FW rule for BRIDGE to accept TPC connections (consider I connect to the DMZ network from a different temporary switch) I can't access the machine

Now, first thing first. Can someone pass some hints how to dynamically pass te IP address to any machine connected to the BRIDGE interface?

cheers

ADDENDUM: I connect a serial console to the box and I see this error shown on the screen:
arpresolve: can't allocate llinfo for 10.xxx.xxx.1
on BRIDGE network and the IP is for the GW and IP of the router/modem