What is .htaccess
.htaccess is a file that Apache reads that allows configuration changes on a per-directory basis. One of the handy little tricks one can do with this configuration file is block visitors from viewing a web site.
The Basics – Blocking 1 IP Address
Order allow,deny Deny from 192.168.0.101 Allow from all
This will refuse all access (GET & POST) to the web site for the IP address 192.168.0.101
The Multiple IP Approach
Order allow,deny Deny from 192.168.0.101 Deny from 192.168.0.102 Deny from 192.168.0.103 Deny from 192.168.0.104 Allow from all
Blocking IP Ranges
Order allow,deny Deny from 192.168.0 ßnotice there is no 101, 102, 103 (this affects a lot of users) Allow from all
IP’s range from 0 – 255 (ex -192.168.0.0 – 192.168.0.255)
You may also block ranges by way of calculating CIDR (Classless Inter-Domain Routing – pronounced “cider”) IP ranges (8, 16, 24bits)
Order allow,deny Deny from 192.168.0/16 Allow from all
You can also block host names instead of numeric addresses.
Order allow,deny Deny from cox.net Allow from all
This will block anyone in the Cox.net network. But beware; banning large isp companies such as Cox.net or Comcast.com will block all their users. Do your research when it comes to blocking hostnames. Think about who may be affected.
There are many other ways of blocking IPs, but using .htaccess is one of the more common requests we receive.