How to use Test-NetConnection to troubleshoot connectivity issues

Last monthsi am working a lot with network issues. One of my favorite tools is the Test-NetConnection command from PowerShell.

Test-Net Connection is a command that can use to troubleshoot networking issues and find out the source of the problem.

Today I would like to explain how can use the  command and which capabilities it has.

Let's start !!

Below you can find different scenarios that you can use the Test-NetConnection command, but you can't limit only to these scenarios.

You can simple

#Scenario 1 - Check the connectivity to specific Site or Public IP Address

Test the ping reply and get details regarding the IP Address of a website

Test-NetConnection -ComputerName www.google.com

However you can use the same command to get more details including the parameter -Information

Test-NetConnection -ComputerName www.google.com  -InformationLevel Detailed

#Scenario 1 - Check the connectivity to specific Server 

Let's see how can use the command to verify connectivity with a Server.

Test-NetConnection -ComputerName <Server/IP Address>

#Scenario 2 - Check if you have connectivity to a Server in specific Port

This command check if the Server has open specific Port.

It's very useful when you want to verify that a Windows, Server has access to another Server in a specific Port.

Test-NetConnection -ComputerName <Server/IP Address> -Port 443

#Scenario 3 - Check your routing from a PC to a Server

The command perform a route diagnostic to a specific server.

Test-NetConnection -ComputerName <Server/IP Address> -DiagnoseRouting  -InformationLevel Detailed

#Scenario 4 - Diagnose your routing from a PC with specific network interface to a Server

Let's see how can perform a route diagnostic to a specific server from a specific network interface.

If you have multiple network interfaces in a Server/Workstation that you want to perform a test the following command can fill your needs.

First run the  Get-NetIPAddress to get a list with your Network Interfaces including the ifIndex.

After that you can run the following command including the Parameter -ConstrainInterface with the ifIndex of the network interface.

Test-NetConnection -ComputerName <Server/IP Address> -DiagnoseRouting -ConstrainInterface 12 -InformationLevel Detailed

#Scenario 5 - Perform a Trace Route from one Endpoint to another.

Last you can use the parameter -TraceRoute to find out the routing of your Server until google.com.

However, this command you can use it to traceroute from one Server to another in your network.

Test-NetConnection -ComputerName www.google.com -TraceRoute

If you want to allow only specific hops with the -TraceRoute  then you can use the parameters -Hops including the number of the Hops that you want to run.

Test-NetConnection -ComputerName www.google.com -TraceRoute -Hops 3

You can find more parameters to run depends of your troubleshooting issue.

However, i found the above commands the most useful in different troubleshooting scenarios . 

I hope to help you learn something today that you will use it in your day to day tasks.