Windows ping via interface

Test connectivity via a specific network interface

Recently while working on a Private cloud implementation, I
came across a scenario where I needed to test connectivity of a node to the
AD/DNS via multiple network adapters. 


Many of us would know that having multiple network routes is usually done to take care of redundancy.
So that if a network adapter goes down, one can use the other network interface
to reach out to the node.

In order to make it easy for everyone to follow along, below
is an analogy for the above scenario:

My laptop has multiple network adapters (say Wi-Fi and Ethernet) connected to the same network. Now how do I test connectivity to a Server on the network only over say Wi-Fi network adapter?

Картинка с сайта: dexterposh.blogspot.com

So let’s get to it and explore some options at hand.

Below are the network adapters that list out on my laptop:

Картинка с сайта: dexterposh.blogspot.com

Now
I want to test connectivity to a Windows Server 2012R2 running in my network
having IP address 10.94.214.9

Using ping.exe

PS>gcm test-netconnection -syntax                                                                                                                                                                                                                           
Test-NetConnection [[-ComputerName] ] [-TraceRoute] [-Hops ] [-InformationLevel ] []                                                                                                                                 
Test-NetConnection [[-ComputerName] ] [-CommonTCPPort]  [-InformationLevel ] []                                                                                                                                   
Test-NetConnection [[-ComputerName] ] -Port  [-InformationLevel ] []                                                                                                                                                 

One could play with route.exe and change the network route
to the network where the server lies and then do a Test-NetConnection on the
winrm port, complicated way to handle such a small problem.

Or better as my friend Jaap Brasser told me on IM, disable the network adapter and then do the Test-NetConnection.

Using TCPClient

Now let’s talk about how we can do this in PowerShell.
I can create a TCP Client and connect to the server on winrm port but how do we
make sure that it gets routed via a specific network interface.

$UsedLocalPorts = ([System.Net.NetworkInformation.IPGlobalProperties]::GetIPGlobalProperties()).GetActiveTcpListeners() |

                        where -FilterScript {$PSitem.AddressFamily -eq ‘Internetwork’} |

                        Select -ExpandProperty Port

Once I have a list of all the used local port, I can select
a non-used ephemeral port (range) using the code snippet below:

do {

        $localport = $(Get-Random -Minimum 49152 -Maximum 65535 )

    } until ( $UsedLocalPorts -notcontains $localport)

Now it is time to create the local endpoint using the source
IP of the network interface and the local unused port.

$LocalIPEndPoint = New-Object -TypeName
System.Net.IPEndPoint -ArgumentList  $SourceIP,$localport

Once the Local endpoint is created, construct a TCP client
passing the local endpoint as an argument to it. This will ensure that the TCP connection request flows via that specific N/W adapter.

Once that is done, call the Connect() Method on the TCPclient to connect to the destination. Now the TCP connection uses the SourceIP (on a specific network adapter) to reach out to the destination.

The ping command is a Command Prompt command used to test the ability of the source computer to reach a specified destination computer. It’s a simple way to verify that a computer can communicate with another computer or network device.

How Does the Ping Command Work?

The ping command operates by sending Internet Control Message Protocol (ICMP) Echo Request messages to the destination computer and waiting for a response. The two major pieces of information that the ping command provides are how many of those responses are returned and how long it takes for them to return.

For example, you might find no responses when pinging a network printer, only to find out that the printer is offline and its cable needs replaced. Or maybe you need to ping a router to verify that your computer can connect to it to eliminate it as a possible cause for a networking issue.

Ping Command Availability

The ping command is available from the Command Prompt in Windows 11, Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP operating systems. It’s also available in older versions of Windows like Windows 98 and 95.

This command can also be found in Command Prompt in the Advanced Startup Options and System Recovery Options repair/recovery menus.

Ping Command Syntax

ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS] [-r count] [-s count] [-w timeout] [-R] [-S srcaddr] [-p] [-4] [-6] target [/?]

How to Read Command Syntax

Other less commonly used switches for the ping command exist including [-j host-list], [-k host-list], and [-c compartment]. Execute ping /? from the Command Prompt for more information on these options.

21 Best Command Prompt Tricks

Ping Command Examples

Below are several examples of commands that use ping.

Ping Google.com

 ping -n 5 -l 1500 www.google.com

In this example, the ping command is used to ping the hostname www.google.com. The -n option tells the ping command to send 5 ICMP Echo Requests instead of the default of 4, and the -l option sets the packet size for each request to 1500 bytes instead of the default of 32 bytes.

The result displayed in the Command Prompt window will look something like this:

 Reply from 172.217.1.142: bytes=1500 time=30ms TTL=54
Reply from 172.217.1.142: bytes=1500 time=30ms TTL=54
Reply from 172.217.1.142: bytes=1500 time=29ms TTL=54
Reply from 172.217.1.142: bytes=1500 time=30ms TTL=54
Reply from 172.217.1.142: bytes=1500 time=31ms TTL=54
Ping statistics for 172.217.1.142:
Packets: Sent = 5, Received = 5, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 29ms, Maximum = 31ms, Average = 30ms

The 0% loss reported under Ping statistics for 74.217.1.142 explains that each ICMP Echo Request message sent to www.google.com was returned. This means that, as far as this network connection goes, it can communicate with Google’s website just fine.

Ping localhost

 ping 127.0.0.1

In the above example, we’re pinging 127.0.0.1, also called the IPv4 localhost IP address or IPv4 loopback IP address, without options.

Using the ping command with this address is an excellent way to test that Windows’ network features are working properly but it says nothing about your own network hardware or your connection to any other computer or device. The IPv6 version of this test would be ping ::1.

Find Hostname With Ping

 ping -a 192.168.1.22

In this example, we’re asking the ping command to find the hostname assigned to the 192.168.1.22 IP address, but to otherwise ping it as normal.

The command might resolve the IP address, 192.168.1.22, as the hostname J3RTY22, for example, and then execute the remainder of the ping with default settings.

Ping Router Command

 ping 192.168.2.1

Similar to the ping command examples above, this one is used to see if your computer can reach your router. The only difference here is that instead of using a ping command switch or pinging the localhost, we’re checking the connection between the computer and the router (192.168.2.1 in this case).

If you’re having trouble logging in to your router or accessing the internet at all, see if your router is accessible with this ping command, of course, replacing 192.168.2.1 with your router’s IP address.

Ping With IPv6

 ping -t -6 SERVER

In this example, we force the ping command to use IPv6 with the -6 option and continue to ping SERVER indefinitely with the -t option. You can interrupt the ping manually with Ctrl+C.

Ping Related Commands

The ping command is often used with other networking related Command Prompt commands like tracert, ipconfig, netstat, and nslookup.

Other Ping Uses

Given the results you see above, it’s clear that you can also use the ping command to find a website’s IP address. Follow that link to learn more about how to do that.

You can also use ping on a Linux computer, and third-party ping tools exist as well which offer more features than the basic ping command.

Thanks for letting us know!