Overview of partner VPN device configurations
This article provides an overview of configuring on-premises VPN devices for connecting to Azure VPN gateways. A sample Azure virtual network and VPN gateway setup is used to show you how to connect to different on-premises VPN device configurations by using the same parameters.
Device requirements
Azure VPN gateways use standard IPsec/IKE protocol suites for site-to-site (S2S) VPN tunnels. For a list of IPsec/IKE parameters and cryptographic algorithms for Azure VPN gateways, see About VPN devices. You can also specify the exact algorithms and key strengths for a specific connection as described in About cryptographic requirements.
Single VPN tunnel
The first configuration in the sample consists of a single S2S VPN tunnel between an Azure VPN gateway and an on-premises VPN device. You can optionally configure the Border Gateway Protocol (BGP) across the VPN tunnel.
For step-by-step instructions to set up a single VPN tunnel, see Configure a site-to-site connection. The following sections specify the connection parameters for the sample configuration and provide a PowerShell script to help you get started.
Connection parameters
This section lists the parameters for the examples that are described in the previous sections.
| Parameter | Value |
|---|---|
| Virtual network address prefixes | 10.11.0.0/16 10.12.0.0/16 |
| Azure VPN gateway IP | Azure VPN Gateway IP |
| On-premises address prefixes | 10.51.0.0/16 10.52.0.0/16 |
| On-premises VPN device IP | On-premises VPN device IP |
| * Virtual network BGP ASN | 65010 |
| * Azure BGP peer IP | 10.12.255.30 |
| * On-premises BGP ASN | 65050 |
| * On-premises BGP peer IP | 10.52.255.254 |
* Optional parameter for BGP only.
Sample PowerShell script
This section provides a sample script to get you started. For detailed instructions, see Create an S2S VPN connection by using PowerShell.
# Declare your variables
$Sub1 = "Replace_With_Your_Subscription_Name"
$RG1 = "TestRG1"
$Location1 = "East US 2"
$VNetName1 = "TestVNet1"
$FESubName1 = "FrontEnd"
$BESubName1 = "Backend"
$GWSubName1 = "GatewaySubnet"
$VNetPrefix11 = "10.11.0.0/16"
$VNetPrefix12 = "10.12.0.0/16"
$FESubPrefix1 = "10.11.0.0/24"
$BESubPrefix1 = "10.12.0.0/24"
$GWSubPrefix1 = "10.12.255.0/27"
$VNet1ASN = 65010
$DNS1 = "8.8.8.8"
$GWName1 = "VNet1GW"
$GWIPName1 = "VNet1GWIP"
$GWIPconfName1 = "gwipconf1"
$Connection15 = "VNet1toSite5"
$LNGName5 = "Site5"
$LNGPrefix50 = "10.52.255.254/32"
$LNGPrefix51 = "10.51.0.0/16"
$LNGPrefix52 = "10.52.0.0/16"
$LNGIP5 = "Your_VPN_Device_IP"
$LNGASN5 = 65050
$BGPPeerIP5 = "10.52.255.254"
# Connect to your subscription and create a new resource group
Connect-AzAccount
Select-AzSubscription -SubscriptionName $Sub1
New-AzResourceGroup -Name $RG1 -Location $Location1
# Create virtual network
$fesub1 = New-AzVirtualNetworkSubnetConfig -Name $FESubName1 -AddressPrefix $FESubPrefix1 $besub1 = New-AzVirtualNetworkSubnetConfig -Name $BESubName1 -AddressPrefix $BESubPrefix1
$gwsub1 = New-AzVirtualNetworkSubnetConfig -Name $GWSubName1 -AddressPrefix $GWSubPrefix1
New-AzVirtualNetwork -Name $VNetName1 -ResourceGroupName $RG1 -Location $Location1 -AddressPrefix $VNetPrefix11,$VNetPrefix12 -Subnet $fesub1,$besub1,$gwsub1
# Create VPN gateway
$gwpip1 = New-AzPublicIpAddress -Name $GWIPName1 -ResourceGroupName $RG1 -Location $Location1 -AllocationMethod Dynamic
$vnet1 = Get-AzVirtualNetwork -Name $VNetName1 -ResourceGroupName $RG1
$subnet1 = Get-AzVirtualNetworkSubnetConfig -Name "GatewaySubnet" -VirtualNetwork $vnet1
$gwipconf1 = New-AzVirtualNetworkGatewayIpConfig -Name $GWIPconfName1 -Subnet $subnet1 -PublicIpAddress $gwpip1
New-AzVirtualNetworkGateway -Name $GWName1 -ResourceGroupName $RG1 -Location $Location1 -IpConfigurations $gwipconf1 -GatewayType Vpn -VpnType RouteBased -GatewaySku VpnGw1 -Asn $VNet1ASN
# Create local network gateway
New-AzLocalNetworkGateway -Name $LNGName5 -ResourceGroupName $RG1 -Location $Location1 -GatewayIpAddress $LNGIP5 -AddressPrefix $LNGPrefix51,$LNGPrefix52 -Asn $LNGASN5 -BgpPeeringAddress $BGPPeerIP5
# Create the S2S VPN connection
$vnet1gw = Get-AzVirtualNetworkGateway -Name $GWName1 -ResourceGroupName $RG1
$lng5gw = Get-AzLocalNetworkGateway -Name $LNGName5 -ResourceGroupName $RG1
New-AzVirtualNetworkGatewayConnection -Name $Connection15 -ResourceGroupName $RG1 -VirtualNetworkGateway1 $vnet1gw -LocalNetworkGateway2 $lng5gw -Location $Location1 -ConnectionType IPsec -SharedKey 'AzureA1b2C3' -EnableBGP $False
(Optional) Use custom IPsec/IKE policy with UsePolicyBasedTrafficSelectors
If your VPN devices don't support any-to-any traffic selectors, such as route-based or VTI-based configurations, create a custom IPsec/IKE policy with the UsePolicyBasedTrafficSelectors option.
Important
You must create an IPsec/IKE policy to enable the UsePolicyBasedTrafficSelectors option on the connection.
The sample script creates an IPsec/IKE policy with the following algorithms and parameters:
- IKEv2: AES256, SHA384, DHGroup24
- IPsec: AES256, SHA1, PFS24, SA Lifetime 7,200 seconds, and 20,480,000 KB (20 GB)
The script applies the IPsec/IKE policy and enables the UsePolicyBasedTrafficSelectors option on the connection.
$ipsecpolicy5 = New-AzIpsecPolicy -IkeEncryption AES256 -IkeIntegrity SHA384 -DhGroup DHGroup24 -IpsecEncryption AES256 -IpsecIntegrity SHA1 -PfsGroup PFS24 -SALifeTimeSeconds 7200 -SADataSizeKilobytes 20480000
$vnet1gw = Get-AzVirtualNetworkGateway -Name $GWName1 -ResourceGroupName $RG1
$lng5gw = Get-AzLocalNetworkGateway -Name $LNGName5 -ResourceGroupName $RG1
New-AzVirtualNetworkGatewayConnection -Name $Connection15 -ResourceGroupName $RG1 -VirtualNetworkGateway1 $vnet1gw -LocalNetworkGateway2 $lng5gw -Location $Location1 -ConnectionType IPsec -SharedKey 'AzureA1b2C3' -EnableBGP $False -IpsecPolicies $ipsecpolicy5 -UsePolicyBasedTrafficSelectors $True
(Optional) Use BGP on S2S VPN connection
When you create the S2S VPN connection, you can optionally use BGP for the VPN gateway. This approach has two differences:
The on-premises address prefixes can be a single host address. The on-premises BGP peer IP address is specified as follows:
New-AzLocalNetworkGateway -Name $LNGName5 -ResourceGroupName $RG1 -Location $Location1 -GatewayIpAddress $LNGIP5 -AddressPrefix $LNGPrefix50 -Asn $LNGASN5 -BgpPeeringAddress $BGPPeerIP5When you create the connection, you must set the -EnableBGP option to $True:
New-AzVirtualNetworkGatewayConnection -Name $Connection15 -ResourceGroupName $RG1 -VirtualNetworkGateway1 $vnet1gw -LocalNetworkGateway2 $lng5gw -Location $Location1 -ConnectionType IPsec -SharedKey 'AzureA1b2C3' -EnableBGP $True
Next steps
For step-by-step instructions to set up active-active VPN gateways, see Configuring active-active VPN gateways for cross-premises and VNet-to-VNet connections.