2022-02-23 Filtering logs to only get relevant reports
I want to know if something goes wrong but with the number of (virtual) servers here at home it is not possible to check all logs constantly. So the main machines use logcheck to find the interesting error messages and the rest gets filtered out. Ideally that leaves no messages, but I do want to know about patterns that indicate attacks so I do get messages constantly about ssh attack attempts and weird nameserver requests or misconfigured nameserver responses. Recently I've been checking the resulting reports again carefully and noticed some more patterns that could be filtered. And I found two misconfigurations that I solved. Normally those misconfigurations would drown in the noise of the log, only to be found if I was looking for something else. Now it started to stand out after filtering out a lot of messages that are to be expected.