Time for action – forwarding requests to cache peers using ACLs

Let's say we have three parent proxy servers (p1.exmaple.com, p2.example.com, and p3.example.com). The proxy server p3.example.com is connected to the internet with a highly reliable, but expensive connection, with a fair usage policy. The proxy servers p1 and p2 are cheaper but unreliable. Also, we have three subnets (academic, research, and finance) on our local area network, according to the following diagram:

Now, let's have a look at the following configuration:

cache_peer p1.example.com parent 3128 3130 round-robin
cache_peer p2.example.com parent 3128 3130 round-robin
cache_peer p3.example.com parent 8080 3130

acl academic src 192.0.2.0/16
acl finance src 198.51.100.0/16
acl research src 203.0.13.0/16

acl imp_domains dstdomain .corporate.example.com .edu

acl ftp proto FTP

cache_peer_access p3.example.com deny ftp
cache_peer_access p3.example.com allow research
cache_peer_access p3.exmaple.com allow academic imp_domains...