.htaccess
Block an IP Address
#Deny List
order allow,deny
deny from 123.123.123.123 #specify a specific address
deny from 123.123.123.123/30 #specify a subnet range
deny from 123.123.* #specify an IP address wildcard
allow from all
Allow an IP address
#Allow List
order allow,deny
allow from 123.123.123.123 #specify a specific address
allow from 123.123.123.123/30 #specify a subnet range
allow from 123.123.* #specify an IP address wildcard
deny from all