Question 1: Procmail 1
Look at the manual pages for procmailrc, procmailex and adapt this rule to send messages from someone@foobar.com to /dev/null unless they are to yourlogin+foo@cs.uchicago.edu. You can test it out by spoofing a mailer (telnet to smtp.cs.uchicago.edu (port 25) and type: "HELO ${whatever machine you are on}", then type: "MAIL FROM: foo@bar.com", then type "RCPT TO: ${to address}", then type: "DATA", enter a message, and end it with a '.' on a line by itself. (Replace ${whatever machine you are on} with the name of the machine you are on, and ${to address} with the address you want the mail sent do.)

Question 2: DNS 1
Produce a /etc/resolv.conf for a machine with the following parameters: (1) host lookups should only be in the domain "foo.bar.com", (2) the nameservers are 111.222.333.1 - 111.222.333.4.

Question 3: DNS 1
Describe the following records (one sentence each --- answers longer than a sentence will get half credit): A, CNAME, NS, MX, HINFO, TXT. See the manual page for named.