Advanced network learning: subnet mask and VLAN division
What is a subnet?
⭐A subnet is a network that divides a large IP address segment into several small IP address segments. Subnets can help network administrators better manage the network and improve network security and efficiency. In a large IP address segment, IP addresses can be assigned to different departments or different offices, so as to realize the allocation and management of network resources.
For example, Internet cafes , or university computer classrooms , I don’t know if they are called like this now, but they were called computer rooms * when I was in school . Basically, one computer controls all the other computers.
Maybe a student is playing a cs shootout game in computer class, and the teacher finds out and cuts off the internet for you directly on his computer.
The teacher can also control all the computers, and the same screen will appear at the same time to give lectures.
The network of all machines comes from the teacher's computer. With this concept in mind, we can understand the meaning of the subnet.
What is a subnet mask?
The subnet mask is a 32-bit binary number used to specify which bits of an IP address are network addresses and which bits are host addresses. A 1 in the subnet mask means the bit is a network address, a 0 means the bit is a host address. The subnet mask is used to divide the network. A large IP address segment can be divided into several small IP address segments through the subnet mask. Each small IP address segment is called a subnet.
⭐View your own subnet mask, easy to operate.
Step 1: Windows + r, open a small window, enter cmd, click OK to
enter the small black frame, this is called a terminal, and each line of English code in it is called a command line.
Step 2: Enter ipconfig and press Enter
This 255.255.255.0 is called the subnet mask
, which means that I am using a subnet of a certain large network. This large network divides this IP address segment into several subnets, and the subnet mask can be changed to 255.255.255.0 , divide the IP address segment into 256 subnets, and each subnet contains 256 IP addresses.
What is VLAN
VLAN is the abbreviation of Virtual Local Area Network (Virtual Local Area Network), which is a technology that divides a physical local area network into multiple logical subnets . VLAN can divide different network devices into different logical subnets, thus improving the security and efficiency of the network. VLAN can be used to isolate the network traffic of different departments or different users, so as to avoid network congestion and security problems.
⭐⭐⭐VLAN 8 important knowledge points
VLANs can be divided in different ways according to different needs. The most common methods are based on port, MAC address, IP address or protocol type. The communication between VLANs needs to be forwarded by routers.
Port-based VLAN is the most common form, which configures each port on the switch as a virtual network segment, which can isolate different devices, thereby improving network performance and security.
MAC address-based VLAN is to put devices with the same MAC address prefix into the same VLAN, which is usually used in wireless networks.
IP address-based VLAN is to put devices in a specific subnet into the same VLAN. This method is usually used for servers and other devices that need to communicate with designated hosts.
Protocol-based VLAN is to put specific types of traffic into different VLANs. For example, VoIP traffic can be put into a dedicated VLAN to ensure its priority and QoS.
A VLAN can contain multiple switches and span multiple physical locations.
VLAN ID is the unique identifier of VLAN, it is a 12-digit number.
VLAN Trunking Protocol (VTP) can be used to manage VLANs, and VTP can automatically configure and synchronize VLAN information in the network.
Relationship between subnet mask and VLAN
⭐⭐⭐
- Subnet masks are used to divide networks, while VLANs are used to divide logical subnets.
- VLAN can divide different physical ports into different logical subnets, and each logical subnet has its own IP address segment and subnet mask.
- With VLAN technology, a large physical network can be divided into multiple logical subnets, thereby improving network efficiency and security.
Subnet mask and VLAN can help us manage the network better and improve the efficiency and security of the network. Through the subnet mask, a large IP address segment can be divided into several small IP address segments, which is convenient for network management and monitoring. With VLAN technology, different physical ports can be divided into different logical subnets, thereby isolating the network traffic of different departments or different users, and avoiding network congestion and security problems.
summary
1. Subnet mask and VLAN are two different concepts, but they are related.
2. The subnet mask is used to determine the network address and host address of an IP address. It can divide an IP address into a network part and a host part, so as to realize communication and management on the network.
3. VLAN (Virtual Local Area Network) is a logical division, which divides a physical local area network (LAN) into multiple virtual subnets, each VLAN has its own broadcast domain, and communication between VLANs A router is required for forwarding.
4. In practical application, VLAN is usually used together with subnet mask to improve the security and manageability of the network. By assigning different VLANs to different subnets, finer-grained network management and isolation can be achieved, thereby improving network security and reliability. At the same time, using VLAN can also achieve better network bandwidth utilization and load balancing.