The device that will fulfill the specifications described in the question is a bridge.
A bridge is a network device that connects two LANs and allows communication between them. It operates at the data link layer of the OSI model, which means that it is responsible for establishing a connection between two devices on the same network and exchanging data between them.
A bridge can also act as a repeater, which means that it can receive a signal on one LAN and retransmit it on the other LAN. This allows the bridge to extend the range of the network and improve its performance.
Additionally, a bridge can filter packets based on their MAC (Media Access Control) address, which is a unique identifier assigned to each device on a network. This allows the bridge to control which packets are forwarded between the LANs and which are blocked, providing a level of security for the network.
Therefore, a bridge is the device that will fulfill the specifications described in the question.