Routers operate at layer 3. LAN switches operate at layer 2. Ethernet hubs operate at layer 1.
Bridge operate on data link layer
Hubs are a physical layer (layer 1) device; most switches operate at the Data Link layer (Layer 2) of the OSI model.
The Transport Layer
Hubs and repeaters operate at the Physical Layer of the OSI Model. The Physical Layer is the first layer of the OSI Model.
Layer 3
Session Layer - layer 5Transport Layer - layer 4
1. Repeaters (Operate at the OSI Physical Layer).2. Bridges (Operate at the OSI Data Link Layer).3. Routers {and Brouters} (Operate at the OSI Network Layer).
no
TCP operates at transport layer
Layer 5 - Session layer
network layer