BRIDGE two interface subnets

[johnied]

Hello,

I have a very curious situation here.
I have a box with 6 interfaces. 3 of them are configured as WANs and 2 of them as LAN and SUBNET.
The LAN CIDR is 192.168.0.0/24.
The SUBNET CIDR is 192.168.1.0/24.
In the SUBNET interface there is an unmanaged switch which is connected to just one device(let's call it DEVICE), with ip 192.168.1.254.
For reasons irrelevant to this post I cannot change the IP of the DEVICE, but it has to be able to connect to the outside world(Internet).

In the SUBNET interface I have configured only the Static IP and the DHCP server.
I have bridged the two interfaces from the Interfaces->Assign->Bridges menu.
I have added a SUBNET firewall rule that looks like:

IPv4 * * * * * * none

Now I can ping the DEVICE from the SUBNET interface(Diagnostics->Ping) but I cant from the LAN interface.

I have done the exact same thing to a router with an internal WIFI antenna to bridge Wifi and LAN interfaces and it worked flawlessly.
What am I doing wrong here?

I have tried setting SUBNET's ip address to None but then I can't ping the DEVICE from the Ping menu.

Thank you and sorry for the long post. I am trying to provide as much details as possible

[Derelict]

Why would you bridge that? You don't use a layer 2 bridge between two different layer 3 networks.

Just enable Internet access from SUBNET…

[johnied]

OK…
But how?
??? ??? ???

[johnied]

And secondly, if I do that will I be able to port forward the DEVICE to the outside world?

[Derelict]

Add the proper firewall rules to SUBNET. If you have not enabled Manual Outbound NAT is should "just work." Look at the rules on LAN. Duplicate it for SUBNET.