viewing firewalld logs via remote login to CentOS 7 server

Question

I have firewalld installed in a remote CentOS server. When I log into the server over the internet as root, I type the following command to access the firewalld logs:

journalctl --output=json-pretty UNIT=firewalld.service  

The result is a few records indicating when the service was turned on, etc.

How do I get the list of attempts that remote users tried to connect with the server? Including ip addresses, whether or not they where blocked by firewalld, what they were requesting, what ports, etc.

Solution

If there is no logging specified in the firewall rule that rejects the connection attempts, then nothing will appear in the log.

I suggest you read the RedHat firewalld reference which discusses adding logging requirements to firewall rules. Unfortunately, it's fairly complex and there are no shortcuts that I know of.