Background: We have a pretty standard web server running on Fly and listening on ports 80 and 443. The app has a single dedicated ipv4 and a single dedicated ipv6 address and is running on 8 machines in different regions. We have a quite a slew of domain names pointing to the app, each with its own SSL certificate. Some domain names reference the app via CNAME and others directly via A and AAAA records. All was working well until recently when an ISP inadvertently blocked our IP addresses in a particular region. The ISP has acknowledged a problem on their end but appears to be incapable of rectifying the issue. We’re considering allocating additional IP addresses for the app and updating our A and AAAA records to point at the new addresses in an attempt to resolve the issue ourselves.
Question/TLDR: Could allocating additional ipv4 and ipv6 addresses for our app disrupt our existing setup in any way? Will our existing SSL certificates work seamlessly for the new IP addresses? Are there any additional things we should consider (caveats, pitfalls, etc.) when adding new addresses?
UPDATE: We added several additional IPv4 and IPv6 addresses to our app and faced no issues. Existing domain names pointing at the original addresses continued to work fine. SSL certs worked fine when we updated some DNS records to point to the new addresses.