Method 1: ping command
Description of ping command
The ping command is a very frequently used network diagnostic tool, which is applicable to Windows, Unix and Linux systems. It is part of the TCP/IP protocol used to determine whether a local host can exchange datagrams with another host. According to the returned information, we can deduce whether the TCP/IP parameter settings are correct and whether the operation is normal. It should be noted that one or two successful datagram exchanges with another host does not mean that the TCP/IP configuration is correct. A large number of datagram exchanges must be successfully performed to be sure of the correctness of TCP/IP. Let's take the Windows system as an example to introduce the basic usage of the ping command.
The ping command uses
Use the shortcut key win+R to bring up the run command box, enter cmd, click OK, and a DOS window will pop up.
click OK
ping baidu.com
ping 163.com
ping 192.168.3.166
To sum up, the format of the ping command is (note that a space needs to be followed by ping)
①Ping IP address or host domain name
②Ping IP address or host domain name + command parameters
③ ping command parameter + IP address or host domain name
ping command parameter description
View ping command help
ping /?
Enter the above command, we can see the printing of the following figure, we can clearly understand the meaning of each parameter
ping 163.com -t
It will keep pinging until the Ctrl+C key combination is pressed to stop
ping 163.com -t -l 1024
-l: Define the size of the sent data packet, which is 32 bytes by default, and can be defined up to 65500 bytes by using it.
often used in work
Method 2: telnet command
Install
Install entry 1
WIN + R shortcut key, enter OptionalFeatures
Install entry 2
open control panel
Click Uninstall a program
Click to turn windows features on and off
Click OK
How to confirm the installation is successful
WIN+R, enter cmd, open the command line terminal, enter telnet, the following figure appears to indicate that the installation is successful
use
1. start
Example: telnet 192.168.31.100 8080
The following information is displayed, proving that the port is enabled:
The following figure shows that port 80 on the server 192.168.3.101 is blocked
2. Exit
First case CTRL+], then enter quit to exit telnet and re-enter the cmd command line
3. Parameter description
Common commands
open : 使用 openhostname 可以建立到主机的 Telnet 连接。
close : 使用命令 close 命令可以关闭现有的 Telnet 连接。
display : 使用 display 命令可以查看 Telnet 客户端的当前设置。
send : 使用 send 命令可以向 Telnet 服务器发送命令。支持以下命令：
ao : 放弃输出命令。
ayt : “Are you there”命令。
esc : 发送当前的转义字符。
ip : 中断进程命令。
synch : 执行 Telnet 同步操作。
brk : 发送信号。
quit 退出telnet。
command abbreviation
c - close 关闭当前连接
d - display 显示操作参数
o - open hostname [port] 连接到主机(默认端口 23)。
q - quit 退出 telnet
set - set 设置选项(键入 'set ?' 获得列表)
sen - send 将字符串发送到服务器
st - status 打印状态信息
u - unset 解除设置选项(键入 'set ?' 获得列表)
?/h - help 打印帮助信息
Method 3: tcping command
Compare with other commands
ping
Everyone is familiar with the ping command, which belongs to the ICMP protocol at the network layer. It can only check the connectivity of the IP or the speed of the network connection, but cannot detect the port status of the IP.
telnet
The telnet command, which belongs to the application layer protocol, is used for remote login and can also be used to detect the port status of the IP. However, the function is limited, and it can only detect the temporary IP port status, and cannot view the ping value, nor can it monitor in real time.
tcping
The tcping command uses the transport layer protocol, which can detect the status of the IP port and view the ping value. Even if the source address is forbidden to ping, the network status of the server can be monitored through tcping .
download
Official website http://www.elifulkerson.com/projects/tcping.php download tcping.exe, the file is less than 300KB.
Put the files under the c:\windows\system32\ and C:\Windows\SysWOW64 directories, and run the tcping command in any file path.
Enter tcping under the command and if the help document appears, the installation command is successful.
WIN+R opens the cmd command line
tcping 163.com
Port is open indicates that the port is open
time=xx.xxms indicates the network delay value
An example of real-time monitoring of the status of a port on the server:
tcping.exe -t -d --tee d:/tcpping.log 163.com 80
The parameter -t means to send data packets continuously until pressing ctrl+c to stop
The parameter -d means to display the detailed date and time in front of each line
The parameter --tee means to output the result to the specified location.
Examples of unreachable ports
tcping.exe -t -d --tee d:/tcpping.log 163.com 81
