11th June 2019

SMS Messaging API SMS API server IP address failover

We added a new proxy server as api2.messente.com DNS A record that forwards the requests to our backend servers that handle the actual API requests.

However there was a configuration error on two backend servers that did no trust the new proxy server's X-Forwarded-For header, which in turn caused the backend server to incorrectly determine the source IP as our new proxy server IP:

We detected the issue and started tracking down the root cause of the error. Meanwhile we also removed the newly added proxy server from the DNS record and created temporary workarounds where possible, to mitigate the problem.

We have now corrected the internal server configuration so that this error would not happen again and we are also improving our deployment scripts to avoid similar issues in the future.