banning IPs from file in Fail2ban

Bekr

10/22/23, 3:57 PM

I've installed fail2ban and it's working fine in banning IPs that try to access ssh with invalid username/password even if they tried once.

Now I'm receiving key exchange attacks that fail2ban doesn't deal with in the default setup.

I created cron that generate the IPs using the command:

sudo cat /var/log/auth.log | grep "Unable to negotiate" | awk '{print $10}' |sort |uniq >> ipsfile

Now I want to add these IPs to fail2ban so I can control the ban in one location rather than splitting the work between IPTables and fail2ban.

I wrote a simple bash:

for IP in $(cat ipsfile); do echo "banning $IP"; sudo fail2ban-client set sshd banip $IP;done

How to make this actually efficient without duplicates?

102

0 + 0

iptables

cron

fail2ban

Elon Musk

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EN: banning IPs from file in Fail2ban

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