Detecting a network within the network protocol

icmp probe ping baidu.com

tcp probe nc ip port
powershell -exec bypass Import-Module .\telnet.ps1 Test-PortConnectivity -Source 'localhost' -RemoteDestination '192.168.3.69' -Port 110 -Iterate -protocol TCP

udp probe powershell -exec bypass Import-Module .\telnet.ps1 Test-PortConnectivity 'localhost' '192.168.3.69' 53 -Iterate -protocol UD

http probe curl vps-ip:8080

dns detect Windows: nslookup www.baidu.com vps-ip
Linux:dig @vps-ip www.baidu.com