sv_filterban
sv_filterban
is a console variable that controls whenever player IP addresses are checked for being banned (an IP filter entry exists) or not.
Syntax:

<
" and ">
" characters.
sv_filterban <value>
- 0 - No checks will happen.
- 1 - All incoming players will be checked if they're IP banned (if they have an IP filter entry), if they are, they will be kicked.