About the port forwarding for one-to-one NAT, can try to enable DMZ on one-to-one NAT. If need to use port forwarding for other devices which did not use one-to-one NAT, virtual server should work....

I am using TP-Link managed switch. They are working perfectly as access layer. But I just used VLAN and layer3 interface and 802.1x. I think TP-Link switch is suitable for small or medium business.

Sorry that I cannot do anything. If your product has console port, we still can try to recover the firmware. But unfortunately TL-SG2452 has not console port. The seller or the courier company should...

I used iperf to test er5120v2 before. It can reach 250mbps.

If the system LED is off, it means that the switch is not working. Since TL-SG2452 has not console port, it's hard to fix it. If you device is during warranty, suggest to ask for RMA.

@Ruben_Zamudio b) Port #3: I need to split it into 2 VLANs: Administration and Public Area You just need to add port 3 to 2 VLANs and set port 3 as tagged port. Suppose that port 3 is connected to a...