Check if Squid is installed and if not, install by performing the following:
Check to see if it is installed by typing rpm -q squid, this should output something like: squid-2.5.STABLE3-0
If not, download the latest rpm from the website shown in Section 2, “Packages required”
su - then type your root password and then rpm -ivh *.rpm in the directory that squid is in.