Redis: NOAUTH Authentication required but there is no password setting

Question

I got error NOAUTH Authentication required when I connect to Redis server via command: redis-cli and run ping to check if Redis is

Answer 1

Had the exact same problem running Redis on an AWS instance. I would restart redis-server without any password requirements (#requirepass ''), would work fine for a few hours, then would throw "NOAUTH Authentication required" and eventually would have to restart redis-server.

Checked the Security Groups settings in AWS for the instance and saw port 6379 open to the public (0.0.0.0/0). We limited the port access to our only server that needs to access and haven't seen the issue come up ever since!

P.S. This is my first ever contribution to StackOverflow. Thanks for the help!