...
When trying to connect to the GMC database for our Nightly nightly synchronisation ETL, our application was getting blocked by the firewall at the GMC, we contacted the GMC to highlight the issue after double-checking our infrastructure to make sure it wasn't anything we were responsible for. They confirmed their oversight, confirming that they had implemented some additional security on 20/07/2021 due to some nefarious activity that was hitting their service. That security update was a little too zealous and blocked our connection to the API. On 21/07/2021 at 11am, GMC added the HEE IP addresses to a ‘whitelist’ which resolved the problem of us connecting to them, but still keeps the unwanted traffic away.
...