Troubleshoot connections with Azure Network Watcher using PowerShell

Learn how to use connection troubleshoot to verify whether a direct TCP connection from a virtual machine to a given endpoint can be established.

Note

This article has been updated to use the new Azure PowerShell Az module. You can still use the AzureRM module, which will continue to receive bug fixes until at least December 2020. To learn more about the new Az module and AzureRM compatibility, see Introducing the new Azure PowerShell Az module. For Az module installation instructions, see Install Azure PowerShell.

Before you begin

  • An instance of Network Watcher in the region you want to troubleshoot a connection.
  • Virtual machines to troubleshoot connections with.

Important

Connection troubleshoot requires that the VM you troubleshoot from has the AzureNetworkWatcherExtension VM extension installed. For installing the extension on a Windows VM visit Azure Network Watcher Agent virtual machine extension for Windows and for Linux VM visit Azure Network Watcher Agent virtual machine extension for Linux. The extension is not required on the destination endpoint.

Check connectivity to a virtual machine

This example checks a connection to a destination virtual machine over port 80. This example requires that you have Network Watcher enabled in the region containing the source VM.

Example

$rgName = "ContosoRG"
$sourceVMName = "MultiTierApp0"
$destVMName = "Database0"

$RG = Get-AzResourceGroup -Name $rgName

$VM1 = Get-AzVM -ResourceGroupName $rgName | Where-Object -Property Name -EQ $sourceVMName
$VM2 = Get-AzVM -ResourceGroupName $rgName | Where-Object -Property Name -EQ $destVMName

$networkWatcher = Get-AzNetworkWatcher | Where-Object -Property Location -EQ -Value $VM1.Location 

Test-AzNetworkWatcherConnectivity -NetworkWatcher $networkWatcher -SourceId $VM1.Id -DestinationId $VM2.Id -DestinationPort 80

Response

The following response is from the previous example. In this response, the ConnectionStatus is Unreachable. You can see that all the probes sent failed. The connectivity failed at the virtual appliance due to a user-configured NetworkSecurityRule named UserRule_Port80, configured to block incoming traffic on port 80. This information can be used to research connection issues.

ConnectionStatus : Unreachable
AvgLatencyInMs   : 
MinLatencyInMs   : 
MaxLatencyInMs   : 
ProbesSent       : 100
ProbesFailed     : 100
Hops             : [
                     {
                       "Type": "Source",
                       "Id": "c5222ea0-3213-4f85-a642-cee63217c2f3",
                       "Address": "10.1.1.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGrou
                   ps/ContosoRG/providers/Microsoft.Network/networkInterfaces/appNic0/ipConfigurat
                   ions/ipconfig1",
                       "NextHopIds": [
                         "9283a9f0-cc5e-4239-8f5e-ae0f3c19fbaa"
                       ],
                       "Issues": []
                     },
                     {
                       "Type": "VirtualAppliance",
                       "Id": "9283a9f0-cc5e-4239-8f5e-ae0f3c19fbaa",
                       "Address": "10.1.2.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGrou
                   ps/ContosoRG/providers/Microsoft.Network/networkInterfaces/fwNic/ipConfiguratio
                   ns/ipconfig1",
                       "NextHopIds": [
                         "0f1500cd-c512-4d43-b431-7267e4e67017"
                       ],
                       "Issues": []
                     },
                     {
                       "Type": "VirtualAppliance",
                       "Id": "0f1500cd-c512-4d43-b431-7267e4e67017",
                       "Address": "10.1.3.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGrou
                   ps/ContosoRG/providers/Microsoft.Network/networkInterfaces/auNic/ipConfiguratio
                   ns/ipconfig1",
                       "NextHopIds": [
                         "a88940f8-5fbe-40da-8d99-1dee89240f64"
                       ],
                       "Issues": [
                         {
                           "Origin": "Outbound",
                           "Severity": "Error",
                           "Type": "NetworkSecurityRule",
                           "Context": [
                             {
                               "key": "RuleName",
                               "value": "UserRule_Port80"
                             }
                           ]
                         }
                       ]
                     },
                     {
                       "Type": "VnetLocal",
                       "Id": "a88940f8-5fbe-40da-8d99-1dee89240f64",
                       "Address": "10.1.4.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGrou
                   ps/ContosoRG/providers/Microsoft.Network/networkInterfaces/dbNic0/ipConfigurati
                   ons/ipconfig1",
                       "NextHopIds": [],
                       "Issues": []
                     }
                   ]

Validate routing issues

This example checks connectivity between a virtual machine and a remote endpoint. This example requires that you have Network Watcher enabled in the region containing the source VM.

Example

$rgName = "ContosoRG"
$sourceVMName = "MultiTierApp0"

$RG = Get-AzResourceGroup -Name $rgName
$VM1 = Get-AzVM -ResourceGroupName $rgName | Where-Object -Property Name -EQ $sourceVMName

$networkWatcher = Get-AzNetworkWatcher | Where-Object -Property Location -EQ -Value $VM1.Location 

Test-AzNetworkWatcherConnectivity -NetworkWatcher $networkWatcher -SourceId $VM1.Id -DestinationAddress 13.107.21.200 -DestinationPort 80

Response

In the following example, the ConnectionStatus is shown as Unreachable. In the Hops details, you can see under Issues that the traffic was blocked due to a UserDefinedRoute.

ConnectionStatus : Unreachable
AvgLatencyInMs   : 
MinLatencyInMs   : 
MaxLatencyInMs   : 
ProbesSent       : 100
ProbesFailed     : 100
Hops             : [
                     {
                       "Type": "Source",
                       "Id": "b4f7bceb-07a3-44ca-8bae-adec6628225f",
                       "Address": "10.1.1.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/ContosoRG/providers/Microsoft.Network/networkInterfaces/appNic0/ipConfigurations/ipconfig1",
                       "NextHopIds": [
                         "3fee8adf-692f-4523-b742-f6fdf6da6584"
                       ],
                       "Issues": [
                         {
                           "Origin": "Outbound",
                           "Severity": "Error",
                           "Type": "UserDefinedRoute",
                           "Context": [
                             {
                               "key": "RouteType",
                               "value": "User"
                             }
                           ]
                         }
                       ]
                     },
                     {
                       "Type": "Destination",
                       "Id": "3fee8adf-692f-4523-b742-f6fdf6da6584",
                       "Address": "13.107.21.200",
                       "ResourceId": "Unknown",
                       "NextHopIds": [],
                       "Issues": []
                     }
                   ]

Check website latency

The following example checks connectivity to a website. This example requires that you have Network Watcher enabled in the region containing the source VM.

Example

$rgName = "ContosoRG"
$sourceVMName = "MultiTierApp0"

$RG = Get-AzResourceGroup -Name $rgName
$VM1 = Get-AzVM -ResourceGroupName $rgName | Where-Object -Property Name -EQ $sourceVMName

$networkWatcher = Get-AzNetworkWatcher | Where-Object -Property Location -EQ -Value $VM1.Location 


Test-AzNetworkWatcherConnectivity -NetworkWatcher $networkWatcher -SourceId $VM1.Id -DestinationAddress https://bing.com/

Response

In the following response, you can see the ConnectionStatus shows as Reachable. When a connection is successful, latency values are provided.

ConnectionStatus : Reachable
AvgLatencyInMs   : 1
MinLatencyInMs   : 0
MaxLatencyInMs   : 7
ProbesSent       : 100
ProbesFailed     : 0
Hops             : [
                     {
                       "Type": "Source",
                       "Id": "1f0e3415-27b0-4bf7-a59d-3e19fb854e3e",
                       "Address": "10.1.1.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/ContosoRG/providers/Microsoft.Network/networkInterfaces/appNic0/ipConfigurations/ipconfig1",
                       "NextHopIds": [
                         "f99f2bd1-42e8-4bbf-85b6-5d21d00c84e0"
                       ],
                       "Issues": []
                     },
                     {
                       "Type": "Internet",
                       "Id": "f99f2bd1-42e8-4bbf-85b6-5d21d00c84e0",
                       "Address": "204.79.197.200",
                       "ResourceId": "Internet",
                       "NextHopIds": [],
                       "Issues": []
                     }
                   ]

Check connectivity to a storage endpoint

The following example checks connectivity from a virtual machine to a blog storage account. This example requires that you have Network Watcher enabled in the region containing the source VM.

Example

$rgName = "ContosoRG"
$sourceVMName = "MultiTierApp0"

$RG = Get-AzResourceGroup -Name $rgName

$VM1 = Get-AzVM -ResourceGroupName $rgName | Where-Object -Property Name -EQ $sourceVMName

$networkWatcher = Get-AzNetworkWatcher | Where-Object -Property Location -EQ -Value $VM1.Location

Test-AzNetworkWatcherConnectivity -NetworkWatcher $networkWatcher -SourceId $VM1.Id -DestinationAddress https://contosostorageexample.blob.core.windows.net/ 

Response

The following json is the example response from running the previous cmdlet. As the destination is reachable, the ConnectionStatus property shows as Reachable. You are provided the details regarding the number of hops required to reach the storage blob and latency.

ConnectionStatus : Reachable
AvgLatencyInMs   : 1
MinLatencyInMs   : 0
MaxLatencyInMs   : 8
ProbesSent       : 100
ProbesFailed     : 0
Hops             : [
                     {
                       "Type": "Source",
                       "Id": "9e7f61d9-fb45-41db-83e2-c815a919b8ed",
                       "Address": "10.1.1.4",
                       "ResourceId": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/ContosoRG/providers/Microsoft.Network/networkInterfaces/appNic0/ipConfigurations/ipconfig1",
                       "NextHopIds": [
                         "1e6d4b3c-7964-4afd-b959-aaa746ee0f15"
                       ],
                       "Issues": []
                     },
                     {
                       "Type": "Internet",
                       "Id": "1e6d4b3c-7964-4afd-b959-aaa746ee0f15",
                       "Address": "13.71.200.248",
                       "ResourceId": "Internet",
                       "NextHopIds": [],
                       "Issues": []
                     }
                   ]

Next steps

Determine whether certain traffic is allowed in or out of your VM by visiting Check IP flow verify.

If traffic is being blocked and it should not be, see Manage Network Security Groups to track down the network security group and security rules that are defined.