I've been trying to get fail2ban to work with the Xeams email spam filter. But, I can't figure out what possible regex I should use to match the logs. The logs are in this format.   1451702136946   5   1451702444872   5  1451705774912   5   1451712868825   5

Each section of the log is separated by a Tab (I think), with the first part being the host IP. I have no idea what the other sections do.

I've tried the following regex but it doesn't work according to fail2ban-regex.

<HOST>      1451.*  .*

As well as:

<HOST>      .*  .*

I honestly have no idea what to do to match these logs.


The problem you are having is that fail2ban expects the line to contain a valid timestamp and your log lines do not meet that criteria as they start with a <HOST>.

In order for a log line to match your failregex, it actually has to match in two parts: the beginning of the line has to match a timestamp pattern or regex, and the remainder of the line has to match your failregex. If the failregex is anchored with a leading ^, then the anchor refers to the start of the remainder of the line, after the timestamp and intervening whitespace

You will need to provide fail2ban with a log file that meets it's input requirements.

| improve this answer | |
  • Any way to use a regex that matches nothing? I'm pretty sure there is no way I can modify the format of the actual log files sadly. – Felix Jen Jan 2 '16 at 7:50
  • No, fail2ban needs the time to work correctly. – user9517 Jan 2 '16 at 7:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.