Difference between Router and Bridge

In this article, we will learn the differences between Router and Bridge networking devices in detail.

Router:

It is an interconnecting device that works at the physical, data link and network layer of OSI reference model. It may connect LAN and WAN in the network and can pass or relay the packets among them. It has access to the network or logical address. The following figure displays the router acts as a station in the network.

In this the routers are a member of more than one network simultaneously. They have links with two or more networks and contain the addresses of the stations on all these networks. It receives the packets from one connected network and passes them to a second connected network. If a received packet contains the address of a node that is on some other network, the Router determines which of its connected networks the best next relay point for that packet.

Bridge

A bridge is a networking device that works in both the physical and data link layer in a network. This devices can divide a large network into smaller segments and pass the frames between two originally separated LANs. A bridge maintains a MAC address of various stations attached to it. When a frames enters a bridge, it checks the address contained in the frame and compares it with a table of all the stations on both segments.

For Example, A-frame is sent from station A to station C. When this frame arrives at the Bridge, the Bridge checks its table and blocks it from crossing into the lower segment as station C is in the upper segment only. Thus, a frame is relayed to the entire upper segment and is not allowed to move to lower segment. If the frame is to be transmitted from station A to station F, the Bridge will allow this frame to pass through it and relay it to the entire lower segment.

Following are the point-to-point comparison between Router and Bridge.

Sr. No	Points of differences	Router	Bridge
1	Function	The main function is to route the packets and to reduce the network problems.	The main function of Bridge is to filter the packets and to keep the traffic for each segment separately.
2	Layers	It is a hardware device that works at the network, data link & physical layer of the OSI Model.	It is a hardware device that works at the OSI model's data link and physical layer.
3	Address	The Router has access to the logical address or IP address of stations.	The Bridge has access to a physical address or MAC address of stations.
4	Protocols	RIP, OSPF, etc. these are some protocols that can be configured in the Router.	In Bridge, there are no protocols to configure.
5	Connection	It connects two or more networks and routes packets between them.	The Bridge is used to extend the existing network or divide or large network into smaller segments.
6	Routing Table	The Router uses a routing table to store information. This table is dynamic and is updated using routing protocols.	The Bridge does not use a routing table for storing information.
7	Data Structure	A router used graph data structure.	Bridge used tables data structures
8	Network Segmentation	In Router enables network segmentation.	In Bridge network segmentation is disable.
9	Domain	It works on more than single broadcast domains.	Bridge works on a single broadcast domain.
10	Transparency	It is not transparent to the end stations.	It is transparent to the end stations and do not rely on the protocol.
11	Efficiency	Routing is more efficient.	The Bridge has less efficiency than the Router.
12	Ports	It has more than two ports.	It has only two ports.
13	Path	Router devices can accommodate multiple paths.	Bridge devices can accommodate a single path.
14	Setup	Difficult	Easy
15	Cost	Routers are relatively expensive devices.	Bridges are relatively inexpensive devices.