Setup a Site to Site IPsec VPN With Strongswan & Meraki MX (IKEv1)

Tags

Azure, Azure VPN Gateway, IKEv1, Meraki, Site2Site VPN, StrongSwan

Recently I am trying to build Site 2 Site IPSEC VPN with Azure VPN gateway and Meraki MX firewall. Meraki start supporting (27th May 2019) IKEv2 in their beta firmware MX 15.13 but it’s not stable.

Please check https://community.meraki.com/t5/Security-SD-WAN/Azure-VPN-IKEv2-intermittent/m-p/47688#M12029 and https://community.meraki.com/t5/Security-SD-WAN/IKEv2-support-on-MX-devices/m-p/48333#M12197

Azure Policy Based VPN gateway (IKEv1) is ok but it only suppotrs one Site 2 Site VPN tunnel.

To overcome the issue; I have created one Ubuntu Server which works as VPN gateway and added User-defined route to route all VPN traffic via Ubuntu Server.

A. Azure Configuration

1. Create a virtual machine. I my case I have created VM with Ubuntu 18.04 LTS with following specification

2. After creating VM go to VM > Networking > Network Interface and Enable IP forwarding settings

3. From NSG make sure UDP/500 and UDP/4500 has been allowed.

4. Create Route Table. 192.168.100.0/24 is the remote subnet and 10.0.0.9 is the IP address of Ubuntu Server.

5. Make sure you associate it with existing network/VNET

Configure Express Route and Site-to-Site coexisting connections

Tags

Azure, Express Route, IPSEC, Meraki

 

We can now configure Express Route and Site-To-Site VPN connection that coexist. Can configure Site-to-Site VPN as a secure failover path for ExpressRoute, or use Site-to-Site VPNs to connect to sites that are not connected through ExpressRoute.

There are some limitation and restriction; for details please check:

https://docs.microsoft.com/en-us/azure/expressroute/expressroute-howto-coexist-resource-manager

In this example I already have VPN Gateway configured with /24 Gateway Subnet

 

Now will create a New VPN Gateway for IPSEC

Step 1: Get the VNET, Gateway Subnet details

$vnet = Get-AzVirtualNetwork -Name SEGResourceGroup-vnet -ResourceGroupName SEGResourceGroup
$subnet = Get-AzVirtualNetworkSubnetConfig -Name 'GatewaySubnet' -VirtualNetwork $vnet

Step 2: New Public IP address and assign it to VPN gateway

$gwpip= New-AzPublicIpAddress -Name SEG-GatewayVPNPublicIP -ResourceGroupName SEGResourceGroup -Location australiaeast -AllocationMethod Dynamic
$gwipconfig = New-AzVirtualNetworkGatewayIpConfig -Name SEG-GatewayVPNPublicIPConfig -SubnetId $subnet.Id -PublicIpAddressId $gwpip.Id

Step 3: Now create site-to-site VPN gateway

New-AzVirtualNetworkGateway -Name SEG-GatewayVPN -ResourceGroupName SEGResourceGroup -Location australiaeast -IpConfigurations $gwipconfig -GatewayType Vpn -VpnType RouteBased -GatewaySku Standard

Verify the VPN Gateway configuration. Important things to check:

GatewayType: VPN

VPNType: RouteBased

VPNClientConfiguration: IkeV2

Step 4: Create the Local Network Gateway