My application log4j2 with a Gelf appender to log messages to our Graylog server.
The configuration is the same in dev, qa, uat, and production. I can view the messages in Graylog from dev, qa, and uat, but production messages are not being received.
I have tested that there is connectivity between production and graylog (UDP on port 12201) by using echo and nc. When a manual test is completed using echo and nc, then I can see the test messages in Graylog.
Does anyone have any other suggestions to troubleshoot this issue?