Hi,
Basic Setup (without going into detailed configuration as there may be a simple answer?). There are 3 Switches connected to the Microtik RB2011UiAS-2HnD unit as per below.
- Port 02 = 8 Port Unmanaged Switch.
- Port 04 = 24 Port Unmanaged Switch attached to Ethernet Port 04
- Port 05 = 24 Port Unmanaged Switch attached to Ethernet Port 05

The Problem:
Port 05 = The PC's connected to the 24 Port “unmanaged” Switch are unable to see or ping themselves. They can however see the PC's connected to the other two switches (on Port 02 & 04).

Question: Is there a specific setting that would prevent the PC's connected via a Switch through Microtik Port 05 from seeing the other PC's attached to the same attached switch?
The PC's connected on Port 02 & 04 have no problems seeing all the PC's including the ones attached to their own switch.

Other Notes: All PC's are managed via a Single DHCP on the Microtik and all Ports are part of the same Single Bridge. All PC's have internet access.

Any advice or suggestion would be most welcome. Thanks in advance.

There can be such setting on the switch - port isolation or something like that, depending on a switch manufacturer.
But this has nothing to do with the mikrotik.

You know............you are absolutely correct. I just completed a test to confirm this i.e. plugged one of the others in and it worked fine so this rules out the Port issue. I should have done that to begin with and before even posting here. Oops!
Not all a loss though as (personally) I have never come across this in any switch I have worked with so didn't even even think about "Port Isolation". Now why would they do such a thing I ask myself. Time for me to read up on that as I am sure there is a good reason other than being a "cheapie D-Link DGS-1024D " Thanks so much for replying so quickly.