Judging from the Internet:

icmp:

ping ip/domaintracert ip/domainpathping ip/domain

tcp:

##vps monitoring## tcp##nc -lvvnp porttelnet ip portnc -zv ip port

udp:

## vps monitor##udp##nc -lvvnup portnc -zuv ip port

http/https:

curl http://xxx.xx.xxwget https://xxx.xx.xx

dns:

ping xxx.comnslookup xxx.comdig xxx.com