If a Clients Local site public IP changes the VPN tunel betwen Azure and the Local Site will disconnect. To fix this do the following:
Connect to Azure using powershell and run the following command:
New-AzureRmLocalNetworkGateway -Name LocalSite -ResourceGroupName [ClientRG] -Location ‘northeurope’ -GatewayIpAddress ‘[Public wan IP 2.4.6.8]’ -AddressPrefix ‘[LAN IP Net 192.168.1.0/24’
(Change the RG and Public wan IP and the LAN IP Net to the correct settings)
