Is there a log file or something where you can look at and see which client (address) is making a cache request? I have used cache manager to look at various things like "IP Cache Stats and Contents". This shows the addresses of the requested (cached) sites but not the address of who requested it.
The access log (on a RH system, /var/log/squid/access.log) shows all of the details of a cache request.
It usually shows things like:
timestamp requesting IP cache or direct request/return code size request - action/remote ip mime type
The 'address' of the requester (the client PC) is the 'requesting IP'. If you want to know who it is, use 'dig' or 'nslookup'.
There are a large number of routines around that can parse this log file and show what you want (hell, I used to throw it in to a DB and do some funky PHP graphs showing usage!), and there's always the ability to write your own.
