Bridge in Computer Networks

Last Updated on April 19, 2023 by Prepbytes

Computer networks are essential in today’s world as they enable communication between various devices and systems. Networks are made up of different components, including bridges. In this article, we will discuss what is bridge in computer networks, functions of a bridge in computer networks, working of bridge, types of bridge in computer networks, advantages, disadvantages, and uses of bridge in computer networks.

What is Bridge in Computer Networks?

A bridge in a computer network is a device that connects two or more LANs or network segments, enabling them to communicate with each other. It operates at the data link layer of the OSI model in computer networks and reads the source address of incoming data packets, forwarding them only to their target destination instead of broadcasting them to all connected segments. This helps reduce network congestion and improve performance.

A Bridge in computer networks can also improve network security by breaking up large LANs into smaller ones, reducing the risk of unauthorized access. Additionally, bridges can establish backup paths across the network, ensuring uninterrupted network connectivity in case of a failure. Overall, bridges are valuable networking devices that can help optimize network performance, enhance security, and ensure reliability.

Functions of Bridge in Computer Networks

Bridges have several functions in computer networks, including:

1. Bridges connect and enable communication between two different networks at the data link layer in an OSI model.
2. Bridges can also extend a network’s physical size.
3. Bridges can also be used to connect a LAN segment in one location to another LAN segment in another location via a synchronous modem connection.
4. To increase performance, bridges are used to divide large, busy networks into smaller, interconnected networks.
5. Bridges, such as hubs and repeaters, broadcast data to all nodes. Yet, the MAC (media access control) address table is constantly being updated in order to identify new segments.
6. Bridges can connect smaller virtual LANs (VLANs) to form bigger VLANs.
7. A wireless bridge is used to connect wireless networks or networks with wireless segments.

Working of Bridge in Computer Networks

A bridge in a computer network operates by inspecting the destination MAC address of incoming data packets and either blocking or forwarding them based on the destination address. When a data frame arrives at the bridge, it reads the destination MAC address and compares it with the address table it has created by monitoring the traffic on the connected network segments. If the destination MAC address is located in the table, the bridge forwards the data frame to the network segment where the destination node is located. If the address is not found, the bridge blocks the data frame and does not allow it to pass through.

Bridges accept all incoming data packets, amplify them, and then forward them to the other side of the bridge. However, they only allow specific packets that are addressed from one network node to another to pass through. This filtering process helps to reduce network congestion and improve network performance.

In order to determine which packets are sent from one LAN to another, the bridge creates an address table that contains the MAC addresses of nodes on each connected network segment. The address table is dynamically updated as new nodes are added or removed from the network, or as the network topology changes.

Overall, the working of a bridge in a computer network involves the inspection and filtering of data packets based on their destination MAC address, and the forwarding of approved packets to the appropriate network segment based on the information stored in the bridge’s address table.

Types of Bridge in Computer Networks

There are three types of bridges in computer networks, which are as follows:

1. Transparent Bridge: Transparent bridges are hidden from other network devices. This bridge does not reconfigure the network whenever a station is added or removed. The transparent bridge’s key responsibility is to either block or forward data based on the MAC address.

2. Source Route Bridge: A source route bridge routes data packets according to the path given by the source device. The path information is included in the data packet by the source device, and the packet is forwarded by the source route bridge along the specified path. This type of bridge is used in specialized network environments and is less popular than transparent bridges.

3. Translation Bridge: A translation bridge is a device that translates network protocols between different network segments. It can translate data packets between network protocols, allowing network devices on separate segments to communicate with one another. Translation bridges are frequently used in networks that employ multiple protocols or architectures.

Advantages of Bridge in Computer Network

Bridge in computer networks offer several advantages, including:

• Improved Network Performance: Bridges can segment the network into smaller parts, reducing congestion and improving network performance.
• Address Learning: A bridge in computer network learns the MAC addresses of devices connected to them and stores them in a table, which allows them to forward data more efficiently.
• Isolation: A bridge can isolate network problems and prevent them from affecting the entire network.
• Filtering: A Bridge in computer networks can filter traffic based on MAC addresses, reducing unnecessary traffic and improving network efficiency.
• Scalability: Bridges can be easily added to a network to connect additional LANs, making them scalable.
• Cost-Effective: A Bridge in computer networks is typically less expensive than routers or switches, making it a cost-effective option for smaller networks.
• Easy to Install: A bridge in computer networks is relatively easy to install and configure, which makes it a good option for small businesses or home networks.

Disadvantages of Bridge in Computer Network

While bridge in computer networks offer several advantages, there are also some disadvantages to consider, including

• Limited Range: A Bridge in computer networks have a limited range and can only connect LANs that are physically close to each other.
• Broadcast Storms: If a bridge receives data with an unknown destination MAC address, it will forward the data to all connected LANs, which can cause a broadcast storm and degrade network performance.
• Security Risks: A Bridge in computer networks does not offer the same level of security features as routers or switches, which may make it more vulnerable to security threats.
• Limited Traffic Control: A Bridge in computer networks does not offer the same level of traffic control as routers or switches, which may limit its usefulness in some network configurations.
• Limited Functionality: A Bridge in computer networks is limited in terms of functionality compared to routers or switches, which may not be sufficient for more complex network requirements.

Uses of Bridge in Computer Networks

A Bridge in computer networks are used for several purposes, including:

• Connecting LANs: A bridge in computer networks is used to connect two or more LANs and enable communication between them. This allows devices on different LANs to communicate with each other.
• Segmenting Networks: Bridges can segment a network into smaller parts, which improves network performance by reducing congestion and increasing the overall speed of the network.
• Extending Wireless Networks: Bridges can be used to extend wireless networks and improve coverage by connecting two or more access points.
• Load Balancing: A bridge in computer networks can balance traffic across multiple LANs, which improves network performance by distributing the load.
• Isolating Network Problems: A bridge in computer networks can isolate problems related to the network, making it easier to troubleshoot and resolve issues.
• Connecting Remote Offices: A bridge in computer networks can be used to connect remote offices and enable communication between them, which is particularly useful for companies with multiple locations.

Conclusion
In conclusion, bridges are useful networking devices that can be used to connect multiple LANs together and increase the performance of the network, scalability, and security. Bridges mainly work by forwarding data packets between LANs based on their destination MAC address. Overall, Bridges can be an important addition to a computer network, but they must be carefully planned and managed to ensure optimal performance and dependability.

FAQs

Here are some frequently asked questions on bridges in computer networks

Q1 – What is a bridge in computer networks?
Ans – A bridge is a networking device that connects multiple LANs together and forwards data packets between them based on their destination MAC address.

Q2 – Can a bridge really improve the performance of the network?
Ans – Yes, a bridge can increase network performance by decreasing the amount of traffic on each LAN and forwarding data packets only to the target destination.

Q3 – How does a bridge helps in providing increased network security?
Ans – A bridge can provide increased network security by filtering out unauthorized traffic based on source and destination MAC addresses. This prevents unauthorized access to the network.

Q4 – What is the difference between a bridge and a switch?
Ans – A bridge and a switch are very similar in functionality, but switches are mostly used in bigger networks and can connect multiple devices on each port, while bridges are mostly used to connect LANs together.

Q5 – Which is better: a router or a bridge?
Ans – Both a bridge and a router operate on different OSI model layers and have different functionality. A router is more intelligent compared to a bridge because it can perform layer 2 bridging functions and route traffic through the same interface at the same time.

Q6 – What is the difference between a repeater and a bridge?
Ans – Bridges can only work on one broadcast network segment, whereas repeaters can forward traffic from all segments. The data link layer functions as a bridge, while the physical layer of the OSI model functions as a repeater. A bridge extends the length of a network segment, whereas a repeater extends the length of a network cable.