Ping packet loss rate: Switch Port failure

Recently, some Internet users in the organization reported that the Network was interrupted when the network was unstable. In light of the actual repair work, I would like to explain some experiences in solving such problems.

I. briefly introduces the Ping packet loss rate Concept

Data is divided into data packets for transmission in the network. Each data packet contains information indicating the data and a token that provides data routing. In general, data packets are transmitted in a small part because the distance between the two terminals is too large to be lost, and most data packets reach the destination terminal. the so-called network packet loss rate is the ratio of the packet loss part to the total number of transmitted packets. during normal transmission, the network packet loss rate should be controlled within a certain range.

In cmd, type ping [url] and the last line (x % loss) is the packet loss rate of the target address ping package.

2. Understand the topology of internet users' broadband access methods (1)

▲Figure 1

Iii. troubleshooting steps

The problem we want to solve this time is that the user's computer packet loss is serious, and sometimes the user's normal internet access is affected. The solution is to find the problem from the bottom up by the user's computer.

4. Identify the problem step by step.

(1) Reasons for user PC Packet Loss during Internet access:

1. Whether the computer Nic is damaged;

2. Whether the RJ45 header is damaged or the line is incorrect;

3. Whether the network cable is damaged;

4. device faults;

Next, use the user's computer and Type ipconfig in cmd to display 2.

▲Figure 2

After obtaining the Gateway of the network (Default Gateway), ping 192.168.0.2-t to obtain the packet loss rate greater than 3.

▲Figure 3

After the above information is obtained, in order to eliminate the fault point, ping 192.168.0.2 from the notebook you carried with you, and the result is still 3. First, you can eliminate the fault that is not the user's computer Nic. Then, check whether the user's crystal head is standardized. In order to be safe, cut off the crystal head and create a new crystal head again, but the fault remains. At this time, we need to find the problem from the user's machine, that is, the method of looking at it.

In order to quickly locate the user's network cable in the 24-port switch, we need the user's help to keep working on pulling and inserting the network cable from the network port, I can see that a light is turned off at the switch indicator. Note that the light is turned off instead of flashing. The above method can be used to determine the port number of the vswitch connected to the user, disconnect the network cable from the switch, connect 7 ports at one end of the direct line, and switch the laptop at one end, still packet loss, this can eliminate the problem of network cable.

It should be noted that the number of Internet users reported for this repair is extremely small, indicating that the vast majority of users in this network access is normal. Find the idle port of the switch and connect it with one end of the direct connection line, one end is connected to the test notebook. The purpose is to test that port is in good condition through this step. If this port fails, try the next one, and so on, and find a good port, test the port as much as possible for a while. In order to save time to test the port, you can always run the ping packet command. After figure 4 appears, it can be determined that the port can be used normally.

▲Figure 4

To ensure the normal use of the port, You can ping the port for a period of time, as shown in Figure 5. You can insert the network cable used for this repair to the tested port and add a label for the next easy repair. Then, run the cmd command on the user's computer, ping192.168.02-t: The network is normal and the ping packet is normal. The repair work has been completed.

V. Summary

The reason for the failure of the switch port is that the performance of the switch is aging, which means that the faulty switch does suffer a decline in hardware performance, so there will be serious packet loss on the Internet. To sum up this work, you should be careful, accumulate more in your daily work, and sum up more. The next time you encounter such problems, you can quickly locate the problem, and quickly solve the problem