CS183: Lab 8

CS183 Lab 8: DNS, Virtual Hosting and Sendmail

Goal: In this lab, you will learn how to setup a DNS server for your favor domain name, host a homepage for your domain and setup an email server for your domain.

Details: You will need the routing setup from Lab 6. Make sure all traffics originated from the Host VM go through the Router VM. Also, make sure your web server is up and running (from Lab 7).

DNS

Install the DNS server. The package name is called bind.
Setup the Router VM to be a master DNS server to serve the domain name "linux.is.better". The Router VM itself will be named as "ns", "fw", "www", and "mail" with IP address 10.0.0.1. The Host VM will be named as "ns2" with IP address 10.0.0.2.
Setup the Router VM to do reserve mapping, ie. IP addresses to names mapping.
Edit /etc/resolv.conf such that 10.0.0.1 is the default name server. Also, add linux.is.better in your search list for hostname lookup. In other words, when doing, for example, "ping www", it is actually doing "ping www.linux.is.better".
Before starting named, the DNS server daemon, make sure to disable iptables first.
Similarly, setup the Host VM, ns2, to be a slave DNS server that receives the domain names from the master DNS server. Make sure /var/named has group writable permission.
Make sure both ns and ns2 can resolve the names like "ns.linux.is.better", "ns2.linux.is.better", "fw.linux.is.better", "www.linux.is.better", and "mail.linux.is.better", as well as the IP addresses "10.0.0.1" and "10.0.0.2". For example, on the Router VM:
```
$ host ns2.linux.is.better 10.0.0.1
$ host ns2.linux.is.better 10.0.0.2
```
both should resolve ns2.linux.is.better to 10.0.0.2. However, the 1st one uses ns (10.0.0.1) while the 2nd one uses ns2 (10.0.0.2) to resolve the names. Show the output of both commands in your report.
Add a new name, ftp.linux.is.better, with IP address 10.0.0.3 to the master server. Make sure the slave server receives that update. Show the result of:
```
$ host ftp.linux.is.better 10.0.0.2
```
in your report.
Make both ns and ns2 to run named over reboot. Show that in your report.

Virtual Hosting

Now, configure your web server (on the Router VM) to serve the pages for your new domain: "linux.is.better". Make sure you are able to get pages from www.linux.is.better via the Host VM. Show that in your report.

Sendmail

Add a new MX Resource Record to your master DNS server, to make mail.linux.is.better your primary mail hub.
Configure sendmail on the Router VM to spool emails for linux.is.better domain. Add the following to /etc/mail/sendmail.cf:
```
Cwlinux.is.better
```
Also, remove "Addr=127.0.0.1" from the "O DaemonPortOptions" line.
Restart sendmail.
Now, send an email (either by mail, sendmail or telnet command) from ns2 to your_account@linux.is.better, where your_account is your regular user account. Make sure your mail server, ns, in this case, receives the email. Show the received email with the email headers in your report.

Questions

Show the result of

$ host ns2.linux.is.better 10.0.0.1
$ host ns2.linux.is.better 10.0.0.2
$ host ftp.linux.is.better 10.0.0.2

from the DNS installation section.

Show that named is running on both ns and ns2 over reboot.
Show the result of requesting a page from www.linux.is.better via the Host VM.
Show the received email including the email headers to your_account@linux.is.better.

Scoring

Attendance - 10%
Question 1 - 10%
Question 2 - 20%
Question 3 - 10%
Question 4 - 10%
The rest of the report - 40%

Notes & Tips:

To get the hint file, a file containing all 13 root name servers, named.ca for example, you can do: dig > named.ca
Make sure to increment the serial number in the zone files on the master DNS server when making changes on the zone files.
Check /var/log/message and /var/log/maillog if something does not work.
A sample lab report can be downloaded from here.