Bridges
One kind of computer network equipment called a bridge connects other bridge networks using the same protocol.
Bridge devices connect two distinct networks and enable communication between them by operating at the data link layer of the Open System Interconnect (OSI) architecture. Bridges broadcast data to every node, much as hubs and repeaters do. Nevertheless, as soon as bridges find new segments, they preserve the media access control (MAC) address table, ensuring that further messages are transmitted to just the intended receiver.
One tool for segmenting a network is a network bridge. The network experiences fewer collisions because each segment represents a distinct collision region. Because a bridge gives each collision zone its own dedicated bandwidth, it also enhances network performance.
Another name for a bridge is a Layer 2 switch. One kind of equipment that is often used in local area networks (LANs) is a network bridge. The reason for this is because a big network may become flooded and clogged by these networks.
If they are unsure about the address of the target node, they have the capability of broadcasting data to every node. A database is used by the bridge.
This database is used to determine the appropriate locations for passing, transmitting, and discarding data frames. Ethernet bridges are another name for network bridges. They establish a connection between two parts of a single network. Bridges are mostly used to split networks into smaller, more manageable segments.
In the OSI model, a bridge operates at Layer 2, or the data connection layer. It evaluates incoming data before determining whether to filter or send it. Every incoming Ethernet frame is examined to determine its MAC address destination. The bridge sends the frame to the appropriate network segment if it finds that the target host is on a different segment.
Take a look at the sample network below:
Four PCs are connected to a network in the image above. A bridge separates the network into several portions. Every segment has its own bandwidth and is a distinct collision domain. Assume that Host A wishes to speak with Host C. The frame with the destination MAC address of Host C will be sent to the bridge by Host A. After examining the frame, the bridge will send it to the network segment that Host C is on.
Although they provide significant advantages over network hubs, network bridges are becoming less used in contemporary LAN architectures. Instead, switches are often used..
Types of bridges in networking
Following are some Types of bridges in networking
- Transparent Bridge
This is a bridge in which the stations are completely unaware of the experience of the bridge. For example, May or May not a bridge is added or deleted from the network, the station’s reconfiguration is unnecessary. This bridge makes use of two different processes like bridge forwarding and bridge learning.
- Source routing bridge
In this bridge, the routing operation is performed by the source station. The frame specifies which route to follow. The hot discovers the frame by sending a special frame which is called a discovery frame. This spreads through the entire network by using all possible paths to the destination.
Advantages of bridges
- Bridges can extend a network.
- Bridges can act as a repeater.
- They can reduce network traffic on a segment.
- They can subdivide the network communication.
- They increase the available bandwidth to individual nodes.
- Bridges reduce collisions as well.
- Bridges can create separate collision domains.
- They can connect different architectures.
Disadvantages of bridges
- They are slower than repeaters.
- Filtering makes them slower.
- They do not filter broadcasts.
- Bridges are more expensive.
- They must use routable protocols.
- They need to understand the protocols which they forward.
- They require a lot of amount for initial configuration.
- These are complex devices.
- These devices are unable to read a specific IP address.
- Its speed is slow.
- Bridges cannot use a firewall as a device.
- They send messages to all the nodes.
- Sending a message to all nodes reduces speed.
- Sending messages to all nodes causes a waste of time.