I want to know what range of IP addresses we need to allow through our firewall to access the LiveAddress API. Can you provide that?

Question

My IT group wants to know what range of IP addresses they need to allow through our firewall to access the LiveAddress API. Can you provide that?

Answer

It's not possible for us to provide a range of IPs as they can change at any time. The best bet is to always rely on the domain name as the source of truth. Here are a few examples of why the IP could change.

1 - We have three sets of active servers, each behind a load balancer in a geo-diverse data center. If one load balancer starts to be unreliable (but still working partly) we would immediately provision a new one. This can take a few hours as it is hardware that has to be installed and then set up. The new one would come online with a new IP address. For a time we would have the old one and the new one active while we make sure everything is working with the new one. Once we are convinced, we would deactivate the "bad" one and everything would be fine. However, it's likely that the new one would have a different IP address.

2 - We need to add a new set of servers to service a larger set of clients. Or maybe even two new sets of servers. That would add two additional IP addresses to the mix.

3 - We are increasingly moving our services to the cloud utilizing Amazon Web Services. Amazon's cloud services DO NOT guarantee a static IP address which means that our IP addresses can change anytime they need them to. You MUST code for dynamic IP addresses. If you choose to NOT account for this, its only a matter of time before your stuff breaks.

So, final verdict, we can't give you a range. It will always be best to either proxy the lookups within your own trusted service, or to utilize nslookup on a regular basis in order to get the current IP values.