We have a customer with a very locked-down network. Any outbound connections require whitelisting of the port and IP address.
However, we are running our system behind an Amazon Elastic Load Balancer (ELB). That means that the IP address of the ELB can change and it is beyond our control.
Is it possible to whitelist a domain name rather than a particular IP address?
I realize this will depend on the customer's IT infrastructure. They are a Windows-only shop, so if there are specific approaches we could take in the Microsoft world, that'd be good. If there are router-specific setups for Cisco, etc, that would also be of interest (in case the customer uses that setup).
Do you have any other suggestions as to how to address this problem?
Use of whitelisting of IP addresses appears to be very brittle... though opening up a particular domain name opens you up to DNS poisoning attacks.