"Walking" or "crossing the bridge"? Router and bridge difference

For the average user to listen to the router and bridge two network devices, it feels very advanced, but for a slightly larger network, there are almost all routers. The router is like a mobile phone in the network system. It is a computer and network. Important equipment for communication, but have you ever thought about how the router works? With the rise of wireless networks, wireless bridges can also form networks, so how does it work? What is the difference between the two? Today, let the author take you inside the network system and see how the router and bridge work.

"Walking" or "crossing the bridge"? ——The difference between router and bridge

1. Router

So what exactly is the router? It is the main node device of the Internet. The router determines the forwarding of data through routing. The forwarding policy is called routing, which is also the origin of the router name (router, forwarder). As a hub for interconnecting different networks, the router system constitutes the main body of the Internet based on TCP/IP. It can also be said that the router constitutes the backbone of the Internet. Its processing speed is one of the main bottlenecks of network communication, and its reliability directly affects the quality of network interconnection. Therefore, in the campus network, regional network, and even the entire Internet research field, router technology has always been at the core, and its development history and direction has become a microcosm of the entire Internet research.

3. Bridge

The Gate Bridge is a function that works on the second layer (data link layer) of the OSI and can reproduce signals between different network segments. It can effectively connect two LANs, and it forwards frames according to the MAC address. Can be seen as a "low-level router." The local communication can be restricted to the local network segment, and the corresponding signal is forwarded to another network segment. The bridge is usually used to connect a small number of network segments of the same type. The remote bridge connects two remote LANs over a generally slow link (such as a telephone line); performance is important for local bridges. With the rise of wireless networks, wireless bridges can also be popular. A wireless bridge is a device similar to a router. It is usually paired, and at two opposite points, each point can transmit and receive signals. For example, the Cisco Aironet 350 Series Wireless Bridge can establish high-speed remote outdoor connections between buildings, which can connect to two or more networks, providing high data transfer rates and excellent data-intensive line-of-sight applications. The throughput rate. The two wireless bridges must be visible and unobstructed. The cost of the wireless bridge is relatively low. Currently, the price of the bridge is generally less than 2,000 yuan, and no cable is required. Interested friends can contact Tianbo, Hui dare not think about it!

4. The difference between bridge and router

As a device that connects the two networks, the bridge and the router are somewhat similar, but they are essentially different. The bridge is also called a bridge, which is a store-and-forward device that implements LAN interconnection at the link layer. The bridge receives the MAC frame from a local area network, unpacks, proofreads, and verifies it, reassembles it in another LAN format, and sends it to its physical layer. Since the bridge is a link layer device, the header added by the protocol above the data link layer is not processed.

Routers, also known as path selectors, are devices that are interconnected at the network layer. It is more complex and more flexible than a bridge. Because routers have stronger interconnection capabilities between different networks, their connection objects include multiple types of networks such as local area networks and wide area networks. The bridge is a simple related device. Its sole purpose is to divide many physical networks that are being shared into smaller parts.

As can be seen from the above, the difference between bridges and routers is mainly reflected in four aspects.

(1) The number of network ports is different. A bridge usually has only two ports. A bridge with more than two ports is called a switch; and a router can have at least 16 ports and up to 48 ports.

(2) The bridge can only connect two identical networks, and the router can connect to different networks; the router is useful for connecting networks for different purposes or different organizations. Users can apply rules or filters to make specific data pass. Without making other data not pass. Or arrange data for a certain purpose to enter a specific network connection, other data skip this connection. The bridge is relatively good in terms of information confidentiality. It connects two peer-to-peer networks, and data is transmitted between the two networks.

(3) The bridge does not isolate the broadcast, and the router can isolate the broadcast.

(4) Different levels of work. The bridge is the second layer of equipment. The bridge does not consider the protocol used by the user on the network. The bridge can transmit data at high speed without selection. The router is the third layer of equipment. Knowing the protocol for transmitting data on the network, you can The transmitted data is controlled (routed) and can be determined by rules to determine how specific data will be processed.

summary

Routers and bridges seem to be very deep, in fact, two physical devices are used to manage the network. Bridges are typically used to connect two identical networks, and routers are not subject to this limitation and can connect to multiple networks. The price of the router is much higher than the price of the bridge.