Azure Virtual Network Gateway VPN Client Connection Limitations Cmdlets

Overview

This section provides detailed information about the PowerShell cmdlets used to manage and understand the limitations of VPN client connections for Azure Virtual Network Gateways. These cmdlets help you monitor, configure, and troubleshoot the maximum number of concurrent VPN client connections supported by your gateway.

Key Concepts

Azure VPN Gateways support establishing secure connections to your on-premises networks and individual clients. Understanding connection limitations is crucial for ensuring network performance and availability. The following concepts are relevant:

Virtual Network Gateway: The Azure resource that acts as a VPN device for your virtual network.
VPN Client Connection: A connection established from an individual user's device (e.g., laptop) to the Azure Virtual Network Gateway.
Connection Limit: The maximum number of concurrent VPN client connections allowed by a specific SKU or configuration of the Azure VPN Gateway.

Cmdlets for Managing Connection Limitations

Get-AzVpnClientConnectionConfiguration

Retrieves the current VPN client connection configuration for a virtual network gateway.

Syntax

Get-AzVpnClientConnectionConfiguration -VirtualNetworkGatewayName <String> -ResourceGroupName <String> [-DefaultProfile <IAzureContextContainer>]

Parameters

-VirtualNetworkGatewayName <String>: The name of the virtual network gateway.
-ResourceGroupName <String>: The name of the resource group.

Example

Get-AzVpnClientConnectionConfiguration -VirtualNetworkGatewayName "MyVpnGateway" -ResourceGroupName "MyResourceGroup"

Set-AzVpnClientConnectionConfiguration

Modifies the VPN client connection configuration for a virtual network gateway. Note that some limitations are tied to the gateway SKU and cannot be changed directly via this cmdlet.

Syntax

Set-AzVpnClientConnectionConfiguration -VirtualNetworkGatewayName <String> -ResourceGroupName <String> [-VpnClientRootCertificates <PSObject[]>] [-VpnClientRevokedCertificates <PSObject[]>] [-DefaultProfile <IAzureContextContainer>]

Parameters

-VirtualNetworkGatewayName <String>: The name of the virtual network gateway.
-ResourceGroupName <String>: The name of the resource group.
-VpnClientRootCertificates <PSObject[]>: Specifies the root certificates for VPN client authentication.
-VpnClientRevokedCertificates <PSObject[]>: Specifies the revoked certificates for VPN client authentication.

Example

$rootCert = New-AzVpnClientRootCertificate -Name "RootCert" -PublicCertData (Get-Content -Path "C:\certs\root.cer" -Encoding Byte -ReadCount 0)
Set-AzVpnClientConnectionConfiguration -VirtualNetworkGatewayName "MyVpnGateway" -ResourceGroupName "MyResourceGroup" -VpnClientRootCertificates $rootCert

Note: This cmdlet primarily affects authentication and authorization aspects of VPN client connections, not the raw connection count limit which is dictated by the gateway SKU.

Understanding Gateway SKUs and Connection Limits

The maximum number of concurrent VPN client connections is determined by the SKU of your Azure Virtual Network Gateway. Different SKUs offer varying levels of performance and capacity. You can find the specific connection limits for each SKU in the Azure VPN Gateway documentation.

To check your gateway's SKU:

Get-AzVirtualNetworkGateway -Name "MyVpnGateway" -ResourceGroupName "MyResourceGroup" | Select-Object Sku

To determine the supported connection limit for a SKU:

Consult the official Azure documentation for the most up-to-date limits. For example, a VpnGw1 SKU might support X concurrent connections, while a VpnGw2 SKU supports Y concurrent connections.

Troubleshooting Common Issues

Connection Limit Reached: If users are unable to connect, verify if the maximum connection limit for your gateway SKU has been reached. You may need to scale up your gateway to a higher SKU.
Authentication Failures: Ensure that client certificates are correctly configured, trusted, and not revoked.
Performance Degradation: High connection counts, especially on lower-tier SKUs, can lead to performance issues. Monitor gateway metrics.

For further assistance, please refer to the official Azure VPN Gateway troubleshooting guides.