We are trying to host multiple sites at the backend of Azure Firewall, however we have about 30 different sites and each with their own test\dev and UAT site, which means 30 x 4 and 120 sites, each one is hosted on port 443, all have their own public IP, and are configured with a DNAT rule for directing the traffic based on the source to the correct backend, we have considered a Azure Application Gateway, with host header redirect, but we haven't had a chance to implement it yet, I was wondering is there a way to be cleverer and use Azure firewall with less public IP's and route to various backends, also the prod public sites have no source specified as they're open to the public.
Hope I've explained that clearly. Thanks