Hi. I am experiencing this strange behavior when using Zoiper android client where it sends register attempts with a username "yes". I suspect this is to keep open the NAT. Anyway, fail2ban does not like this, as you can imagine, and it bans the user. Can someone help me to add an ignoreregex for fail2ban please. The strings that are causing it to fail are: 2017-11-14 17:19:41.716109 [WARNING] sofia_reg.c:1775 SIP auth challenge (REGISTER) on sofia profile 'default' for [yes@196.22.1.22] from ip 105.184.98.99 2017-11-14 17:19:41.756109 [WARNING] sofia_reg.c:2889 Can't find user [yes@196.22.1.22] from 105.184.98.99 maybe this would work... ignoreregex= \[WARNING\] sofia_reg.c:\d+ SIP auth challenge \(REGISTER\) on sofia profile \'[^']+\' for \[yes@.*\] from ip <HOST> my regex skills are lacking... Thanks in advance Clive