How do I ping a specific port of a remote server?

Transfered from Linux Config Disqus comments:

Question:

How do I ping a specific port of a remote server? I need to find out whether the port on the remote server is open.

Answer:
ping utility does not allow you to ping specific port on you remote server. To see whether a specific port is open on a remote server you can use port-scanner such as nmap or simply try connect to a socket ( IP-address:port ) using telnet. In the example below we test whether a port number of TCP port 80 is open a host google.com:


# nmap -p 80 -sT google.com

or

# nmap -p 80 google.com 
 To test a UDP port 80 use:

# nmap -p 80 -sU google.com 

other way to test whether a specific port is open on a remote server is to use telnet command. Below we test whether a port 443 on host google.com is open:


# telnet google.com 443 Trying 74.125.237.19... Connected to google.com. Escape character is '^]'.