We have a client who wants to connect their premises to Azure. Their main hindrance at this point is determining the best way to connect to Azure given their current connectivity configuration. They have two redundant ISP connections going to the head office for internet access. They want to be able to configure a VPN connection to Azure that would operate in a similar way i.e. if ISP A went down it would seamlessly use ISP B and vice versa. The normal multi-site VPN configuration does not fit this since there is one local network behind which means the network behind separate VPNs over each ISP would have overlapping IP address ranges which is not supported. Is such a configuration possible? (See diagram below)
Either that or is there a way to abstract the two ISP connections onto one VPN connection to Azure.
They’re currently considering using a Cisco ASA device to help with this. I’m not familiar with the features of this device so I cannot verify if it will solve their issue. I know there is also a Cisco ASAv appliance in the Azure marketplace don't know if that could also be a part of a possible solution if they went with such a device.