LibreNMS - snmp extend fail2ban

Fail2ban LibreNMS script

Get the script and make it executable:

wget https://github.com/librenms/librenms-agent/raw/master/snmp/fail2ban -O /etc/snmp/fail2ban && chmod +x /etc/snmp/fail2ban

sudo Configuration

Adapt your /etc/sudoers with:

Debian-snmp ALL=(ALL) NOPASSWD: /etc/snmp/fail2ban

SNMP Configuration

Adapt your /etc/snmp/snmpd.conf with:

extend fail2ban /usr/bin/sudo /etc/snmp/fail2ban -c -U

Restart the service.

Crontab

Add to the crontab:

*/3    *    *    *    *    root    /etc/snmp/fail2ban -u

Check Command

Adapt the user and path to your configuration:

sudo -u Debian-snmp /etc/snmp/fail2ban

In case of bug with the Perl @NIC, execute:

cpan JSON

Sources

• https://docs.librenms.org/Extensions/Applications/#fail2ban

---