Shulou(Shulou.com)11/24 Report--

After a tired day, I finally got home, turned on the computer and rushed to join the fight, but I frequently encountered network stutters.

As the old saying goes, it is better to ask for help than to ask for help. Instead of waiting for rescue in a crash, learn a little trick to solve the network stutter easily.

Mr. documentation explains to you a magical gadget-the ping command, with which you can easily test whether the network is open.

What is the ping command? Ping is a network diagnostic tool that works as a service command in the application layer of the TCP / IP network architecture and is usually used to test network connectivity between hosts. The ping command sends an ICMP (Internet Control Message Protocol) echo request to the target host, and if the target host can respond, the Ping command receives an ICMP echo reply to confirm the network connection between the hosts.

Ping command form, common parameter options and meaning:

Ping [- t] [- a] [- n count] [- l size] [- f] [- I TTL] [- s count] [[- j host-list] | [- k host-list]] [- S srcaddr] target_name

How does the ping command check the network? The ping command can help us to judge whether the network is abnormal. According to the results displayed by the ping command, we can determine the round-trip time of sending and receiving each packet, and report the percentage of unresponsive packets, which can reflect whether the network is connected correctly and the packet loss rate, and diagnose the network problems quickly.

Next, the document will take the network connection failure as an example to see how ping locates the network failure.

1. Click start run in the system, type cmd in the run bar, and open the command prompt.

two。 Enter the ping command at the command prompt. First, the gateway address of the ping private network (how to get the gateway? When you run ipconfig from the command prompt, the packet loss rate is 0 and the ping value is normal (the ping value of the wired network is generally less than 1ms, while the ping value of the wireless network is between 1ms-20ms). This means that the private network is unblocked.

Example: assume that the gateway address of the private network is 192.168.1.1.

If there is packet loss or the ping value is high, then the problem lies in the private network. Need to troubleshoot internal network cables, loops, switches and other equipment problems.

3. When there is no problem with the private network, ping the IP address of the public network. For example, we can ping the IP address of Baidu to check whether the public network is unobstructed. On the public network, the ping value (1ms-50ms) is higher. Can ping and the ping value is normal without packet loss, which means that the public network is normal, otherwise the public network is abnormal, and you need to troubleshoot the router and WAN port line problems.

4. If the public network can be connected to ping, but still can not be online, through the ping domain name to judge. Normally, the IP address can be resolved through the domain name. If the IP cannot be parsed, there is a problem with the DNS.

5.ping results do not show [from... The format of the reply.] all means that ping does not understand. There are many reasons why ping cannot be connected, such as network failure, prohibition of ping, IP shielding and so on. The display results vary with different faults. Here are some common ping failures:

The request timeout network is normal, but the other server does not allow us to ping or the IP is prohibited in our area. For some reasons, we cannot visit some websites. When we ping these sites, we can get the IP address of the site, but we will prompt [request timeout] from. Reply: the request that the target host ping cannot be accessed was not sent.

It is possible that the other host is not powered on, IP error, gateway setting error and other reasons.

General failures may be caused by disconnection of the network, damage to the registry, incorrect settings when the firewall is on, and so on. The ping request could not find the host URL address. Please check the name and try again. The computer is not connected to the Internet. For example, the Baidu URL of ping shows that the host www.baidu.com cannot be found in the ping request. Please check the name and try again. ], indicating that the computer is not connected to the network To sum up: when there is a network failure, you can first ping Baidu, if ping does not reach Baidu, and then ping the gateway. If you can ping the gateway, it means that the network problem is on the router (you can log in to the router at this time to check the reason). You can try to restart the router. If the fault still exists, the problem may lie in the optical cat or optical fiber (in this case, you can call maintenance customer service).

If you cannot ping the gateway, there is a problem with the connection between the computer and the router.

When wired connection: ping is not connected to the gateway, generally, the network cable is too long, broken, aging or crystal head problems.

Wireless connection: the ping gateway may be too crowded, such as shopping malls and other areas with high traffic, connected to the wifi hotspot but show that the exclamation mark does not have a network.

The ping command also fails to do something to note that the ping command does not test all types of network failures.

Cannot test all problems in the network: the ping command can only test indicators such as connectivity and response time between two hosts in the network, not all problems in the network.

Packet loss rate is not entirely accurate: packets sent by ping commands may be discarded due to network congestion, firewalls and other reasons, resulting in the result of packet loss rate is not completely accurate.

Affected by the target host: the result of the ping command is affected by the target host, and if the target host is unable to respond in time due to high load or other reasons, the result of the ping command will also be affected.

Therefore, when using the ping command, you need to use it with caution and analyze it in conjunction with other network diagnostic tools.

Today, Mr. Archive has learned with you:

What is the ping command?

How does the ping command check the network?

There are things you can't do with the ping command.

This article comes from the official account of Wechat: ZTE documents (ID:ztedoc)

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