How to perform a TCP ping

Normal ping using ICMP, not TCP nor UDP.

But sometimes we want to check whether a port is open or not.
For example I establish a new service on my server but find out client cannot get access.
That's time when we should use TCP ping.

So how can we perform TCP ping?

If you are using Windows, you can use tcping, a simple CLI tool brought to you by Eli Fulkerson, which can be downloaded here.

If you are using Linux, then you have multiple useful choices.
The first is nmap.You can use it like this

nmap -p 80 onofri.org

The second is tcpping brought to you by Richard. Click here for tutorial.
There are some other tool can perform TCP ping too, e.g. Hping, Paping.

If you'd prefer web application, there are many websites that offer a bunch of Network tesing tool such as ping, tcping, tracert, etc. Just Google it.