fail2ban/config/filter.d/sshd.conf

# Fail2Ban configuration file
#
# Author: Cyril Jaquier
#
# $Revision$
#

[Definition]

# Option:  failregex
# Notes.:  regex to match the password failures messages in the logfile.
# Values:  TEXT
#
failregex = (?:(?:Authentication failure|Failed [-/\w+]+) for(?: [iI](?:llegal|nvalid) user)?|[Ii](?:llegal|nvalid) user|ROOT LOGIN REFUSED) .*(?: from|FROM) (?:::f{4,6}:)?(?P<host>\S*)

# Option:  ignoreregex
# Notes.:  regex to ignore. If this regex matches, the line is ignored.
# Values:  TEXT
#
ignoreregex =