Switches are one of the most common devices in the weak power industry, so how much do you know about switch-related terms? Today take you to understand together!

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1. Switch

Switch is a device used to realize the switched network, in the iSO OSI model, it is located in the second layer - data link layer of equipment, can operate on the frame, is an intelligent device.

2. IEEE 802.3

Ethernet standards.

3. IEEE 802.3u

Fast Ethernet standard.

4. IEEE 802.3ab

Gigabit Ethernet (unshielded twisted pair) standard.

5. IEEE 802.3z

Gigabit Ethernet (optical fiber, copper) standard.
IEEE 802.3x

Flow control standards.

7. IEEE 802.1X

Port-based access control standards.

8. IEEE 802.1q

VLAN standard.

9. IEEE 802.1p

Traffic priority control standard.

10. IEEE 802.1d

Spanning tree protocol

11. Data link layer

Located at the second layer of the ISO/OSI reference model, it is responsible for error-free transmission of one frame of data over the line between nodes through a series of means such as detection, flow control, and retransmission, so that from its previous layer (the network layer) it appears to be an error-free link.

12. Full and half duplex

In the network, full duplex means that receiving and sending use two independent channels, which can be carried out at the same time without interfering with each other. Half duplex is to receive and send the same channel, at the same time can only send or receive, so half duplex may cause conflicts. The switch we are talking about is a full-duplex device, and the hub is a half-duplex device.

13. MAC address

The MAC address is the address used in the media access layer, which is the physical address of the network card (LAN node). In the physical transmission process at the bottom of the network, the host (LAN node) is identified by the physical address, which is generally unique in the world. Nowadays, MAC addresses are generally 6 bytes and 48 bits.

14. IP address

An IP address is a 32-bit address assigned to each host connected to the Internet. Each host can be accessed through an IP address.

15. Auto-Negotiation

The Auto-Negotiation standard ADAPTS the switch to the operating rate and operating mode in the following order: 100M full duplex, 100M half duplex, 10M full duplex, 10M half duplex.

16. Full duplex flow control

Following the IEEE 802.3x standard, network devices use predefined Pause frames for flow control when the network is congested.

17. Half duplex flow control (Backpressure technology Backpressure)

Based on the IEEE802.3x standard, when the processor finds that the buffer is about to fill up, it sends a false collision signal to the source station, delays it for a random time, and then continues transmitting. Can relieve and eliminate congestion.

18. Line speed

Theoretical maximum value of data forwarded by the switch.

19. Broadcast storm control

Abnormal phenomenon in which the number of broadcast frames on the network (as a result of being forwarded) increases dramatically and affects normal network communication. Broadcast storms can occupy a considerable amount of network bandwidth and cause the entire network to fail to function properly. Broadcast storm control allows ports to filter broadcast storms that occur on the network. After broadcast storm control is enabled, the port automatically discards the received broadcast frames when the number of broadcast frames reaches a preset threshold. If this function is disabled or the number of broadcast frames does not reach the threshold, broadcast frames are normally broadcast to other ports on the switch.


20. TRUNK (Port aggregation)

It is often used to aggregate multiple ports together to form a high-bandwidth data transmission channel. The switch treats all ports clustered together as one logical port.

21. VLAN (VirtualLocal Area Network)

Is a broadcast domain composed of a group of terminal workstations, hosts in the same VLAN (switch port) can communicate with each other, it does not need to consider the specific cabling structure can establish a logical working group. Flexible configuration improves system security.

22. Port VLAN

Port-based VLAN: Ports on the same VLAN can communicate with each other.

23. Tag VLAN

Based on IEEE 802.1Q, different vlans are divided by VID.

24. VID (VLAN ID)

Id of a VLAN, which is used to represent a Tag VLAN.

25. MTU VLAN

When configuring the VLAN on the switch, the ports occupied by each user and the uplink ports are divided into a separate VLAN.

26. MAC address aging time

Each port on the switch has the function of automatically learning addresses. The source addresses (source MAC address and switch port number) of frames sent and received through the port are stored in the address table. Aging time is a parameter that affects the learning process of a switch. The time starts after an address record is added to the address table. If the ports do not receive frames with the source MAC address within the aging time, these addresses are deleted from the dynamic forwarding address table (consisting of the source MAC address, destination MAC address, and the corresponding switch port number). Static MAC address table is not affected by the address aging time.

27. Static address table

Static MAC addresses are different from learned dynamic MAC addresses. Once a static address is added, the address remains valid until it is deleted and is not subject to the maximum aging time. The static address table records the static addresses of ports. A MAC address in a static address table corresponds to a port. If this is set, all data sent to this address is forwarded only to this port. Also known as MAC address binding.

28.MAC address filtering

MAC address filtering Allows the switch to filter data frames that are not expected to be forwarded. When a restricted MAC address is connected to the switch, the switch automatically filters out the frames whose destination address is this address for security purposes. The addresses in the filtering address table are valid for all switch ports. An address that has been added to the filtering address table cannot be added to the static address table or dynamically bound to a port.

29. Dynamic MAC address binding

Dynamic address binding means that ports on the switch can dynamically learn MAC addresses in the dynamic address binding state. However, the number of addresses that can be learned is limited. When a port learns a MAC address, it is bound immediately and learns the next MAC address. The bound address is not limited by the aging time and takes effect all the time. After the port learns a certain number of addresses, it does not learn and bind any more. The MAC address bound by a port is deleted only after the port address binding function is disabled or the switch is restarted.

30. Port security

After port security is enabled on a port, the port does not learn new MAC addresses and forwards only the learned MAC addresses. Other data frames are discarded. If the source address of the frame sent to the switch is a member of the MAC address table of the port, the frame can be forwarded. Otherwise, the frame is discarded. When Disable is selected for a port, the port automatically learns a new MAC address and forwards received frames.

31. Port bandwidth control

The input/output data transfer rate of each port (except the module port) can be limited by bandwidth.

32. Port monitoring

Port monitoring replicates the packets from the monitored port to the monitoring port. A host installed with the data packet analysis software is connected to the monitoring port. The network administrator analyzes the collected data packets to monitor the network and rectify network faults.

33. Check cables

When the switch port is connected to a suitable twisted pair, you can test the status of the twisted pair through the switch to confirm whether there is a problem and where the problem occurs.

34. SNMP

Simple NetworkManagement Protocol (SNMP) is an OSI Layer 7 (application layer) protocol used to remotely monitor and configure network devices. SNMP enables network management workstations to read and modify the Settings of gateways, routers, switches, and other network devices.

35. InternetGroup Management Protocol (IGMP)

IP manages multicast communications through the use of switches, multicast routers, and IGMP-enabled hosts. A group of hosts, routers (or switches) communicate multicast data streams with members belonging to the same multicast group. And all devices in this group use the same multicast group address. IGMP Snooping greatly improves network utilization for applications such as VOD. In the network, when conducting IP multicast communication for a wide variety of multimedia applications, you can reduce unnecessary bandwidth usage by setting IGMP on each port of the switch.

36. IEEE 802.1D/STP

When the IEEE 802.1D Spanning Tree Protocol detects loops on the network, loops are automatically disconnected. If multiple connections exist between switches, only the most important connection is enabled, and all other connections are blocked and become standby connections. When the primary connection fails, the spanning tree protocol automatically uses the secondary connection to take over the primary connection without any manual intervention.

37. IEEE 802.1X authentication protocol

Port-based Access Control Protocol (Port BaseNetwork Access Control Protocol). The protocol architecture is divided into three parts: client, authentication system and authentication server.