Test-Connection is a PowerShell cmdlet in Windows that allows users to send ICMP echo requests to test the reachability of a network device. It is similar to the traditional "ping" command but offers more flexibility and detailed output. This article will guide you through using Test-Connection to troubleshoot network connectivity issues effectively.

Examples:

1. Basic Usage: To perform a simple ping test to a remote host, you can use the following command:

   Test-Connection -ComputerName www.google.com

   This command sends four ICMP echo requests to the specified computer (in this case, www.google.com) and returns the results.

2. Specifying the Number of Pings: You can specify the number of echo requests to send using the -Count parameter:

   Test-Connection -ComputerName www.google.com -Count 10

   This command sends 10 ICMP echo requests to www.google.com.

3. Testing Multiple Hosts: You can test the connectivity to multiple hosts by specifying an array of computer names:

   Test-Connection -ComputerName www.google.com, www.microsoft.com, www.github.com

   This command tests connectivity to all three specified hosts.

4. Using Test-Connection with Additional Parameters: Test-Connection can also be used with additional parameters to customize the test further, such as setting the buffer size or the delay between pings:

   Test-Connection -ComputerName www.google.com -Count 5 -BufferSize 64 -Delay 2

   This command sends five ICMP echo requests with a buffer size of 64 bytes and a 2-second delay between each request.

5. Checking Connectivity with Detailed Output: To get more detailed output, you can use the -Detailed parameter:

   Test-Connection -ComputerName www.google.com -Detailed

   This command provides a more comprehensive output, including the response time for each ping.

6. Using Test-Connection in a Script: Test-Connection can be incorporated into PowerShell scripts for automated network testing:

   $hosts = @("www.google.com", "www.microsoft.com", "www.github.com")
   foreach ($host in $hosts) {
      $result = Test-Connection -ComputerName $host -Count 2
      if ($result.StatusCode -eq 0) {
          Write-Host "$host is reachable"
      } else {
          Write-Host "$host is not reachable"
      }
   }

   This script tests the connectivity of each host in the array and reports whether each host is reachable.