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jaygooby
Asked: 2021-10-22 01:22:33 +0800 CST

Can fail2ban-client tell me if an ip from a CIDR range is in a jail? [duplicate]

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If I have a CIDR like 13.54.63.128/26 can fail2ban-client tell me if there's an IP in this range that's currently banned?

Currently I'm doing:

CIDR="13.54.63.128/26"
nmap -sL -n $CIDR | awk '/Nmap scan report/{print $NF}' | while read ip
do
  sudo iptables -L -n | grep $ip
done

which does the job, but feels a bit hacky.

Please note this is not a question concerning fail2ban's partial IP matching. I want to know the client's ability to report on banned IPs.

fail2ban cidr

1 Answers

  1. There is a nifty little tool grepcidr that is useful for quick shell scripts that need to find matches from a specific CIDR in a list with IPv4 or IPv6 addresses.

     sudo iptables -L -n | grepcidr  "13.54.63.128/26"
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