Many friends who learn Xi network knowledge often see half-duplex and full-duplex functions when configuring switches.
THE EARLY NETWORK EQUIPMENT HUB (HUB) WAS HALF-DUPLEX, AND NOW THERE IS BASICALLY NO USE OF IT, AND THE SWITCH (SWITCH) USED NOW IS FULL-DUPLEX.
a. Half-duplex: The interface can only receive or send data at any time, and there is a limit to the maximum transmission distance.
Half-duplex is like a walkie-talkie, if someone wants to pass the voice to another person, it has to press a certain button and then speak. When the button is pressed, the information is transmitted to only one method, so they cannot hear the other person's voice when transmitting the voice, and the button must be released in order to receive the other person's voice.
b. Full-duplex: The interface can receive and send data at the same time, and the maximum throughput can reach double the rate, and the physical distance limitation of half-duplex is eliminated.
As a result, a full-duplex system has twice as much bandwidth as a half-duplex system because the device can send and receive data at the same time.
A good example of full-duplex is telephone communication. When you're talking to someone on the phone, you can address and listen to each other at the same time. So you don't have to wait, you can talk and listen at the same time.
Configure Ethernet interface rate and duplex mode in either auto-negotiation or non-auto-negotiation mode.
a. In auto-negotiation mode, the interface rate and duplex mode are determined by the interface negotiation at both ends of the link. Once the agreement is approved, the devices at both ends of the link are locked to the same duplex mode and interface rate. The auto-negotiation feature can take effect only when both devices on both ends of the link support it. If the peer device does not support the auto-negotiation function, or the auto-negotiation mode of the peer device is inconsistent with the local device, the interface may be in the Down state.
b. When the peer device does not support the self-negotiation function, or the device cannot be connected after the self-negotiation function is configured, and there are a large number of packet errors or packet loss on the interface after physical connection, the user can configure the interface to work in non-self-negotiation mode, manually configure the interface rate and duplex mode, and adjust the interface rate and duplex mode.
Ethernet's interface duplex mode
Ethernet interface rate and duplex mode support
How to resolve congestion in your network
Server farms (Server1, Server2, and Server3) are connected to GE0/0/1, GE0/0/2, and GE0/0/3 of the Switch, respectively, and the Switch connects to the Internet network through GE0/0/4.
Due to the special limitations of the server NIC, interfaces GE0/0/1, GE0/0/2, and GE0/0/3 can only be auto-negotiated in half-duplex mode, and packet loss occurs when the service data traffic is large.
At the same time, the rate of GE0/0/1, GE0/0/2, and GE0/0/3 is self-negotiated to a maximum rate of 1000 Mbit/s. Users want to solve data loss and congestion problems.
1. Configure the networking diagram of rate and duplex mode in non-auto-negotiation mode
2. The configuration idea is as follows:
Configure the interface to work in non-auto-negotiation mode to prevent the server NIC from affecting the final working rate of the device interface.
In non-auto-negotiation mode, the duplex mode of the interface is forced to be full-duplex to avoid data packet loss.
In non-auto-negotiation mode, the working rate of the specified interface is forced to be 100 Mbit/s to avoid data congestion.
3. Configuration steps
Step 1: Create a port group and add GE0/0/1, GE0/0/2, and GE0/0/3 to the port group
Step 2: Configure APIs GE0/0/1, GE0/0/2, and GE0/0/3 in batch to work in non-auto-negotiation mode, full duplex mode, and 100 Mbit/s in duplex mode
Step 3: Verify the configuration result Run the display interface gigabitethernet 0/0/1 command in any view to check the current working rate and duplex mode of the interface.
From the above echo fields, it can be seen that the interface works in non-auto-negotiation mode, the working rate is 100 Mbit/s, and the duplex mode is full-duplex. Similarly, for GE0/0/2 and GE0/0/3, you can run the display interface gigabitethernet 0/0/2 and display interface gigabitethernet 0/0/3 commands to check the current working information of the interface.