Site A 22.214.171.124 (Primary)
Site B 126.96.36.199 (Primary)
From a routing point of view with 2 routers at each site and advertisements via BGP I don't see this being a problem. We'll advertise both networks at each site. However, primarily only site A will get 188.8.131.52 traffic and site B will get 184.108.40.206 traffic. No problems there with NAT and so forth.
What I don't know how to handle at the moment is if say site B fails and site A starts receiving 220.127.116.11 traffic. There will be just a single link between site A's router and firewall, with the 20.x.x.x network. Any recommendations how site A can receive 18.104.22.168 seamlessly if site B were to fail? (from an ASA/NAT Point of view)
Is it safe to assume that your ASA has a route to the 22.214.171.124 network from it's inside interface ?
static (inside,outside) 126.96.36.199 188.8.131.52 netmask 255.0.0.0
as long as traffic for 184.108.40.206 is then routed to the outside interface of site A firewall it can then accept this traffic and forward it on internally.
If i have misunderstood let me know.