Broadcast domain and conflict domain

in LAN technology, the two words of conflict and broadcast domain have a great impact on network performance, let's take a look at how these two words affect network performance.
1. The conflict zone of LAN technology

if you want to drive off the freeway, but every time you try, there is a car blocking your way. If forced out, collisions occur, similar to what happens on an Ethernet network using a carrier-listening multi-access (CSMA/CD) protocol with conflict detection. The Institute of Electrical and Electronics Engineers (IEEE) defines CSMA/CD ethernet as the 802.3 standard, which is now used throughout the network community. The Open Systems Interconnection model (OSI) second layer of media access control (MAC) sub-layer is the use of the CSMA/CD protocol to access physical media.

all nodes in the network can send data whenever they need it, while the CSMA/CD network strives to ensure that only one node is sending data at any one time. However, it is possible for two nodes to send data at the same time, node 1 and Node 4 in example 1-1. When this happens, it can lead to collisions. This is the same as what we just said about taking the car out of the freeway, because there is no other car in the way, and as you drive out, another car hits you at 100 miles per hour.

However, one thing that is different from a crash on a motorway is that it is difficult to recover after a collision, while the network node can continue to listen for lines. If a device detects a collision, it stops sending and notifies the other node of the collision. All other nodes that are being sent are notified to stop sending. Collisions occur only in Ethernet. The only thing we care about is how much the collision frequency will affect network performance. Don't know if this analogy makes you understand what a conflict domain is?

The concept of conflict domains can also be explained by the LEDs on the front panel of the Ethernet hub at work to help users detect when the network segment is saturated with collisions. Even though there are several tools that can detect slow network speeds and bottlenecks, I think it's fast and convenient to use LED lights on the hub. There is a network segment whose hub indicates that the LED light on the collision has always been on, but surprisingly, I have never heard any of the users in that segment complain. I know it may be hard to believe, but it's true!

Figure 1-1 Simultaneous transmission of two nodes in Ethernet

2. LAN Technology broadcast Domain

Before discussing the broadcast domain, you must first understand what a broadcast is. A broadcast is data that is sent to all nodes on a network segment, not to a single node or to a group of nodes. To broadcast the node to send data to Mac 0xFFFFFFFFFFFF, you can achieve the above purposes. Therefore, the broadcast domain consists of a set of nodes capable of receiving broadcast messages from all other nodes in the same group. Typically, all nodes that are connected to one port on the router, such as the Hub, form a broadcast domain, as shown in 1-2.

For these networks, all 1 6 nodes make up this broadcast domain. Node 2 on the H U B 3 broadcasts not only to the host on the H U B 3, but also to all hosts on H U B 1, h U B 2, and H U B 4. The hosts on H U B 1, h U B 2, and H U B 4 also broadcast to all other nodes.

The number of broadcast packet encounters in broadcast domain increases with the increase of network scale. All of these broadcast messages do affect the performance of the network and, if improperly managed, can even cause the entire network to crash.

Broadcast domain and conflict domain