Several Basic concepts of networks

Several Basic concepts of the network today began to learn the basics of network interconnection. I found myself vague in some devices and network concepts. The first is the Broadcast Domain and Collision Domain ). In short, a broadcast domain is a collection of all devices in the same CIDR block. These devices listen to all the broadcasts sent in this CIDR block. What is a CIDR Block? A cidr Block refers to the part in a computer network that uses the same physical layer device (transmission medium, repeater, Hub, etc.) for direct communication [Baidu Encyclopedia: CIDR block]. A conflict domain means that when a network device sends data over the network, other devices in the network segment where the device is located must re-transmit the data if the device sends the data. That is to say, the conflicted domain is a collection of all devices competing on the same network segment. If the device in this network segment has data to send, you must be aware that other devices are using communication channels to send data. Second, there are switches, hubs, bridges, and routers. A hub is a physical layer device that does not recognize or analyze data. It simply forwards data from other interfaces. All hosts connected to the Hub belong to the same conflict domain and belong to the same broadcast domain. The switch exchanges frames between ports in the network. Each port of a vswitch is an independent conflict domain, but belongs to the same broadcast domain. The functions of the bridge are basically the same as those of the switch, and can be divided into multiple conflicting domains. A vro is actually a vswitch. The vro uses a logical address, which is different from the forwarding or filtering frame of the vswitch on the second layer. When a vro is used, each LAN interface belongs to an independent broadcast domain, which also separates conflicting domains.