Time for action – using a range of IP addresses to build ACL lists

Now, let's say in a company, the marketing department is spread over five floors. We have used a convention 10.1.FLOOR_NUM.MACHINE_NUM to assign IP addresses to each machine on every floor. The floor number starts from two and goes up to six. So, we basically have the following subnets.

10.1.2.0/24 # 2nd Floor
10.1.3.0/24 # 3rd Floor
10.1.4.0/24 # 4th Floor
10.1.5.0/24 # 5th Floor
10.1.6.0/24 # 6th Floor

A simple way to identify all these client computers is defined in the following ACL:

acl mkt_dept src 10.1.2.0/24 10.1.3.0/24 10.1.4.0/24 10.1.5.0/24 10.1.6.0/24

The previous methods are a bit cluttered and long winded. Squid provides a simple way to specify multiple addresses the following is an example of this:

acl mkt_dept src 10.1.2.0-10.1.6.0/24

The preceding ACL defining mkt_dept is simply a shortened version of the following:

acl mkt_dept src 10.1.2.0/24
acl mkt_dept src 10.1.3.0/24
acl mkt_dept src 10.1.4.0/24
acl mkt_dept...