Difference between the bridge and gateway

In a computer network, physical devices are used to communicate from one to another. These devices are also called Network Hardware. The primary functions in computer networks are Connectivity and controlling of the network traffic. The network can be expanded or separated using network devices.

A network device to regenerate incoming signal before retransmission to the receiver over a distance in the OSI model is known as Bridge. Gateway is a node to connect two disparate networks using two different protocols.

What is Bridge?

A network unit in which the connection of two different LANs in the same protocol is known as a Bridge. In two different LAN’s the frames are transmitted.

The network hardware like a bridge works in the Data link layer. A bridge is a repeater with reading the MAC address from the source to filter the content. The bridge is two port device because it has one input and one output port.

The bridges can be used to monitor the traffic from the computers and detect the computer causing the traffic issue in the connected network. The address of each network node is stored and based on the stored address packet is forwarded to the destination. The bridge segments the network into the smaller network. The bridge divides the network with separate bandwidths. Also, keep the traffic separate side of the Bridge.


In bridges, there are three types, Source routing bridge, Transparent bridge, and Translation Bridge.

  • Source routing bridge − The path is determined by the source device and based on the content of the MAC frame header a routing decision is taken.

    The source address field information is followed by information on the router field. The discovery frame is the frame when the special frame is sent by the host through all possible paths to the destination in an extended LAN network.

  • Transparent Bridge − The most popular bridge in which the devices are invisible. In this bridge, it is not known whether the network was added or deleted and reconfiguration is not necessary. There are two functions bridge learning and bridge forwarding.

  • Translation Bridge − The two different LANs are connected which is used to change from one to another networking system. For instance: Token ring networks, Ethernet, etc.

From the address information, the bridge analyses the incoming packets and forwarding packets.

The bridge also decreases network congestion and filters the error-causing links by isolating them and high-level error detection. Moreover more features of security can be added. The integration of LAN into multiple segments can be done using Bridge.

Bridges are scalable, manageable, easy to install, and reliable. The disadvantage of bridges is only two networks links to the bridge and broadcast data. Bridges cannot filter packets based on protocol and are also not able to interpret high-level information.

What is Gateway?

Different protocols are connected by a device using a disparate network known as Gateway. It is an entry point of the host network through a remote network.

The Gateway is more complex and powerful as compared to the bridge.

Gateway is also called Proxy servers or firewall servers. The routing of data is done by gateways. Also depending on data flow there are many types of gateway, Bidirectional, unidirectional, Network, cloud storage gateway, etc. The Gateway may give the translation between two such as Electrical components and media. The gateway is more flexible than the bridge as translates the address between two different networks.

The difference between the bridge and gateway are highlighted in the following table −

Basis of Difference




The connecting device between two LANs.

The gate for the passage between two different networks.

Layer in OSI model

The data link layer and the physical layer are used

Operates in all layers of the network.


Same protocol but a different LAN

A different protocol is used to transfer the packet in the network. It is a protocol converter

The main cause of the existence

The main cause of voltage drop is the current flowing through a circuit element.

The main cause of the potential difference is EMF (Electromotive Force).

Form of data

The bridge works with frames.

In the gateway also packet is the form of transferring data.


The packet format is not changed

The packet format is changed


The router is not used for installation

The router is used for installation.


The receiving frame in the bridge regenerates and the destination address of the frame is checked which forwards to the address it is received.

Communication between two different protocols of two different networks.


The path for transmitting the frame increases efficiency and regenerating the signal is done by a bridge.

In a communication to increase compatibility in the different networks using a different protocol.


To conclude, Gateway, bridges are the main component of computer networking. The bridge operates in the same protocol employed in different networks. In the gateway, two different network works using two different protocol which means two local networks can be connected using different protocols. Gateway is the interface that allows two networks to connect.

Updated on: 14-Apr-2023

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