First, the levels are different.
1. Repeater: Repeater is used as an intermediate device in the physical layer.
2. Bridge: As an intermediate device, the bridge is used in the data link layer.
3. Router: The router is used as an intermediate device. Used in the network layer.
4. Gateway: Gateway is used as an intermediate device in the transport layer.
Second, the transmission units are different.
1. repeater: the transmission unit of the repeater is the data group.
2. Bridge: The transmission unit of a bridge is a data frame.
3. Router: The transmission unit of router is data packet.
4. Gateway: The transmission unit of the gateway is data bytes.
Third, the function is different.
1. Repeater: Repeater is used to connect two network segments of the same type, and its main function is to extend network segments and change transmission media.
2. Bridge: A bridge can connect two LANs, so that local communication is limited to this network segment and the corresponding signals are forwarded to another network segment.
3. Router: The router checks the IP address in the data, ignores the destination address if it belongs to the local network, and forwards the packet outside the local network if it belongs to other networks.
4. Gateway: The gateway uses different transmission protocols to translate and convert data in two network segments.