Your objective is to set up tinydns on your virtual server dns so that you now can resolve names for your domain, and so that your dnscache references your tinydns when queried about your domain.
Probably the simplest way to do this is to setup tinydns to listen and respond on the loopback interface on your virtual server dns; continue to have dnscache listen and respond over the 192.168 interface. Have dnscache consult the loopback interface (where tinydns is running) for any queries about .YOURDOMAIN.
The names that you should be able to resolve for your domain are: dns.YOURDOMAIN, mail.YOURDOMAIN, s1.YOURDOMAIN, s2.YOURDOMAIN, imap.YOURDOMAIN, and webmail.YOURDOMAIN. For imap and webmail, have those both as aliases for mail.
Finally, make sure that your caching nameserver is the only one listed in the resolv.conf files for all of your machines, both real and virtual and that everything is resolving correctly.
(N.B.: The following installations can be done from yum; I don't recommend that you use a source installation for any of them since it's not necessary — none of them are particularly balky to install from source, but there are some details that can vary a bit from the Redhat configuration.)
Next install postfix on your mail machine, and configure it to receive mail for your domain. Your test cases should include mailing from each of your real and virtual machines.
Then install dovecot on your mail machine, and configure it to talk with clients anywhere both with pop and with imap. Test it with telnet localhost 110, telnet localhost 143, and telnet imap.YOURDOMAIN 110.
Finally, install squirrelmail on both s2 and on mail. Verify that each works from all machines, and test that it works with the alias webmail.YOURDOMAIN.
A journal is due for this assignment. Make sure that you document in your journal all of the steps that you went through, following the guidelines on the class home page. Please share the workload so that all team members get experience with all aspects of the work. Do not forget to assign your work percentages to yourself and your other teammates in your journal. Please turn in a printed copy of this assignment at the beginning of class on Monday, July 21st.