We earn commission when you buy through affiliate links.

This does not influence our reviews or recommendations.Learn more.

Wondering how to check connectivity between two data pipe endpoints?

One of the common tasks for sysadmin is to check the connectivity to troubleshootnetworking issues.

Whatever it might be, the following utility/commands would help you.

They are tested on CentOS, and I dont see any reason not to work on another Linux distro.

The syntax for the command is easy.

If there is no issue in connecting, then you should see the connected message.

In most of the scenarios, telnet should help.

However, if you need some other option then here are some telnet alternatives.

ncat or nc

Ncat (a.k.a.

It works on IPv4 and IPv6, both.

Lets take an example of testing 443 port on geekflare.com.

As mentioned, you’re free to also usencto bind the connection tolisten on a particular port.

This can be handy when you dont have actual services running but want to ensure connectivity exists.

To start listening on a port:

It will bind the port to a given number.

wget

wget is a useful command to download/test HTTP, HTTPS, and FTP.

If you are working as a web engineer or often dealing with web-related issues thenwgetis your friend.

Testing using wget is straightforward.

Here is an example of testing tools.geekflare.com

If it shows connected means there is no connectivity issue.

Check out this to see some of the frequently usedwget command examples.

curl

Acurlis a multipurpose tool.

Do you know it’s possible for you to telnet to a port using curl?

Well, now you know.

The following is a working example.

nmap

A popular tool with hundreds of features.

Often this is considered as a security tool,nmaplets you test a single IP/port or in the range.

To test a single port

An example of testing port 443 on siterelic.com

Look at the state column.

Keep in mind, this may not give you accurate results when ICMP is blocked at the remote networksfirewall.

For example, success result of geekflare.com

For example, failure result of internal IP.

If the endpoint supports IPv6, it’s possible for you to use theping6command as below.

Conclusion

telnet is phasing out in the latest Linux version.

Thanks to the above telnet alternative.

If you are new to Linux and looking to learn then check out thisUdemy course.