Layer 2, the data-link layer.
Layer 2 , Data Link Layer
What_are_the_devices_used_in_osi_transport_layerNetwork Devices Used in Transport Layer: The Brouter (Bridge router), Gateway and Cable tester work on the transport layer.for more about devices used in 7 layers of OSI model go: http://www.networktutorials.info/osi_layers.html
bridges, Switches and NIC..
Layer 1 (hubs) or Layer 2 (bridges or switches) devices.
Bridges
some bridges are used to get to the other side of something
The most common types of straight bridges used in civil engineering projects are beam bridges, truss bridges, and arch bridges.
Switches / Bridges and hubs work at data link layer, but there are layer three switches which operate at network layer. Dhruv
The geometric shape used in truss bridges is the triangle.
layer 3 layer 3 Switch/ Bridges / Hubs works at layer 2 as they utilizes MAC address to communicate. However i aggree above stated answer as there are some layer three switches that work at Layer3 i.e. Network Layer. Dhruv
Stone bridges were built to get over rivers etc, before iron or steel was used.
The most common materials used in bridge building are generally steel or concrete for larger bridges, and stone or wood for smaller bridges.