open squid.conf on any of the text editor
vim /etc/squid/squid.conf
and add te below lines to add an access list
acl ipacl url_regex http://[0-9]*/.[0-9]*/.[0-9]*/.[0-9]*
http_access deny ipacl
You need back slash before dot in the url_regex. otherwise all the URLs will
be blocked.
