What do the relevant terms in the switch mean? It is necessary to figure out

Switch

A switch is a device used to implement a switched network. In the OSI model of the iSO, it is a device at the second layer, the data link layer, which can operate on a frame and is an intelligent device.

2. IEEE 802.3

Ethernet standard

3. IEEE 802.3u

Fast Ethernet standard

4. IEEE 802.3ab

Gigabit Ethernet (unshielded twisted pair) standard

5. IEEE 802.3z

Gigabit Ethernet (fiber, copper) standard

6. IEEE 802.3x

Flow control standard

7. IEEE 802.1X

Port-based access control standard

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 in the second layer of the ISO/OSI reference model, it is responsible for transmitting one frame of data error-free through a series of means such as detection, flow control and retransmission on the line between nodes, so that it is from the upper layer (network layer) ) looks like an error-free link.

12. Full and half duplex

In the network, full-duplex means that two separate channels are used for receiving and transmitting, which can be performed simultaneously without mutual interference. Half-duplex is a channel shared between receiving and transmitting. It can only be sent or received at the same time, so half-duplex may cause conflict. 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. The popular point is the physical address of the network card (LAN node). In the physical transmission process under the network, the host (local area network node) is identified by the physical address, and it is generally global. The current MAC address is 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 allows the switch to adapt 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, when the network is congested, the network device uses a predefined Pause frame for flow control.

17. Half-duplex flow control (backpressure technology Backpressure)

Based on the IEEE 802.3x standard, when the processor finds that the buffer is about to fill up, it sends a false collision signal to the originating station, delaying it for a random time, and then continuing to transmit. Can alleviate and eliminate congestion.

18. Line speed

The theoretical maximum value of the switch forwarding data.

19. Broadcast Storm Control

The number of broadcast frames on the network (due to being forwarded) increases sharply and affects the abnormality of normal network communication. The broadcast storm will occupy a fairly objective network bandwidth, causing the entire network to fail to work properly. Broadcast storm control allows ports to filter broadcast storms that occur on the network. After broadcast storm control is enabled, when a broadcast frame received by a port accumulates to a predetermined threshold, the port automatically discards the received broadcast frame. When this feature is not enabled or the broadcast frame is not accumulated to the threshold, the broadcast frame will be broadcast normally to other ports on the switch.

20. TRUNK (port aggregation)

Usually used to aggregate multiple ports together to form a high-bandwidth data transmission channel. The switch treats all ports that are grouped together as one logical port.

21. VLAN (Virtual Local Area Network)

It is a broadcast domain consisting of a group of terminal workstations. Hosts (switch ports) in the same VLAN can communicate with each other. It can establish logical working groups without considering the specific wiring structure. Flexible configuration and increased system security.

22. Port VLAN

Port-based VLANs can communicate with each other between the same VLAN port.

23. Tag VLAN

Based on IEEE 802.1Q, VID is used to divide different VLANs.

24. VID (VLAN ID)

An identifier for a VLAN that represents a Tag VLAN.

25. MTU VLAN

When the switch is configured with a VLAN, the port occupied by each user and the uplink port are divided into a single VLAN.

26. MAC address aging time

Each port in the switch has an automatic learning address function. The source address (source MAC address, switch port number) of the frame sent and received through the port is stored in the address table. Aging time is a parameter that affects the learning process of the switch. After an address record is added to the address table, the time is counted. If the port does not receive the frame whose source address is the MAC address within the aging time, then these addresses will be forwarded from the dynamic address table (by the source MAC address, the destination MAC address, and They are deleted in the port number of their corresponding switch). The static MAC address table is not affected by the address aging time.

27. Static Address Table

The static MAC address is distinguished from the general dynamic MAC address obtained by learning. Once a static address is added, the address will remain valid until it is deleted, and is not subject to the maximum aging time. The static address table records the static address of the port. A MAC address in the static address table corresponds to a port. If set, all data sent to this address will be forwarded only to that port. Also become a MAC address binding.

28.MAC address filtering

MAC address filtering is configured by filtering the address and allowing the switch to filter data frames that are not expected to be forwarded. When the restricted MAC address is connected to the switch, the switch will automatically filter out the frame whose destination address is this address for security purposes. The address in the filter address table is valid for all switch ports. Addresses that have been added to the filter address table cannot be added to the static address table or dynamically bound by the port.

29. Dynamic MAC address binding

Dynamic address binding means that the port of the switch can dynamically learn the MAC address in the state of dynamic address binding. However, the number of addresses that can be learned is limited. When the port learns a MAC address, it is bound immediately, and then learns the next address. The bound address is not subject to the aging time and will remain in effect. After the port learns a certain number of addresses, it no longer learns and binds. The MAC address bound by the port will not be deleted until the port address binding function is disabled or the switch is restarted.

30. Port Security

When a port is enabled for port security, the port will not learn the new MAC address and will only forward the data frame of the learned MAC address, and other data frames will be discarded. The judgment condition is: the frame sent to the switch is allowed to be forwarded if its source address is a member of the MAC address table of the port, otherwise it will be discarded. When the port security option is "disabled", the port will resume learning the new MAC address automatically and forwarding the received frame.

31. Port Bandwidth Control

The input and output data transmission rates of each port (except the module port) can be limited by the bandwidth.

32. Port monitoring

Port monitoring is to copy the packets of the monitored port to the monitoring port. The monitoring port is connected to a host with the packet analysis software installed. The network administrator analyzes the collected data packets to perform network monitoring and network elimination. malfunction.

33. Cable detection

When the switch port is connected to a suitable twisted pair cable, the status of the twisted pair cable can be tested through the switch to confirm the problem and the problem.

34. SNMP

The Simple Network Management Protocol (SNMP) is an OSI Layer 7 (application layer) protocol for remote monitoring and configuration of network devices. SNMP enables network management workstations to read and modify settings for gateways, routers, switches, and other network devices.

35. IGMP (Internet Group Management Protocol)

IP manages multicast traffic by using switches, multicast routers, and IGMP-enabled hosts. A group of hosts, routers (or switches) exchanges 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 technology greatly improves network utilization for applications such as video on demand. In the network, when IP multicast communication is used for a variety of multimedia applications, you can reduce unnecessary bandwidth usage by setting IGMP on each port of the switch.

36. IEEE 802.1D/STP

The IEEE 802.1D Spanning Tree Protocol automatically disconnects the loop when it detects a loop on the network. When there are multiple connections between switches, only the most important one will be started, and the other connections will be blocked, making these connections redundant. When there is a problem with the primary connection, the spanning tree protocol will automatically initiate the backup connection to take over the primary connection without any human intervention.

37. IEEE 802.1X Authentication Protocol

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