Apache Reference: mod_proxy, ProxyBlock

ProxyBlock

Block Proxy Connections to Targets
Syntax: ProxyBlock target [target ...]
Example: ProxyBlock cybersex *.sex.com
Since: Apache 1.2

This directive specifies a list of URL substrings, host names, and domain names, separated by spaces. The proxy server will block HTTP, HTTPS, and FTP document requests to those targets. In addition, mod_==proxy will attempt to determine the IP addresses of those list items that may be host names during start-up and use them for matching. The special target ``*'' blocks all proxy connections.