Question

Using Ubuntu, what are the commands for the following:

1. Installing and running a DNS server (BIND9) in a chroot jail on your server with a non-root user.

2. Configure your DNS server to be able to answer queries for the following FQDNs.  
   1. server.cis415.edu (Your Ubuntu Server’s IP)
   2. client1.cis415.edu (Client1’s IP)
   3. client2.cis415.edu (Client2’s IP)

Answer 1

• Bind is the most popular software and the most widely used Domain Name System (DNS) software on the Internet for providing DNS services. The name BIND stands for “Berkeley Internet Name Domain” and it’s an implementation of the DNS protocols.
• A "jail" is a software mechanism for limiting the ability of a process to access resources outside a very limited area, and it's done with security in mind.A jail is created using the chroot() system call (named for "change root"), and it's given a directory name as a parameter. Once this call is made, the root - the top of the directory tree - for this process is changed from / to the directory given, and there is no way for the process to get outside this area.

1. Install Bind9 :

                      ehowstuff@ehowstuff:~$ sudo apt-get install bind9 -y

2. Setup and configure zone with the name of ehowstuff.local

          ehowstuff@ehowstuff:~$ sudo vim /etc/bind/named.conf.local

Add a DNS zone to BIND9. Edit named.conf.local as below :

          //include "/etc/bind/zones.rfc1918";

           zone "ehowstuff.local" {

             type master;

             file "/etc/bind/db.ehowstuff.local";

            };

      ~

3. Copy and Use an existing zone file as a template:

    ehowstuff@ehowstuff:/etc/bind$ sudo cp /etc/bind/db.local /etc/bind/db.ehow

Edit the new zone file db.ehowstuff.local.

   ehowstuff@ehowstuff:~$ sudo vim /etc/bind/db.ehowstuff.local

Change configuration as below :

;

; BIND data file for local loopback interface

;

$TTL    604800

@       IN      SOA     ns.ehowstuff.local. root.ehowstuff.local. (

                              2         ; Serial

                         604800         ; Refresh

                          86400         ; Retry

                        2419200         ; Expire

                         604800 )       ; Negative Cache TTL

;

@       IN      NS      ns.ehowstuff.local.

ns      IN      A       192.168.1.49

box     IN      A       192.168.1.49

4. Any changes that you’ve made to the zone file BIND9 will need to be restarted before it to take effect:

   ehowstuff@ehowstuff:~$ sudo /etc/init.d/bind9 restart

 * Stopping domain name service... bind9                                            [ OK ]

 * Starting domain name service... bind9                                            [ OK ]

5. Make sure you own workstation or server pointing to dns server. In this case, this Ubuntu server pointed to itself since it’s running bind9.

      ehowstuff@ehowstuff:~$ sudo vim /etc/resolv.conf

      nameserver 127.0.0.1

6. Test bind9 server :

     ehowstuff@ehowstuff:~$ nslookup

     > set type=ns

     > ehowstuff.local

    Server:         127.0.0.1

    Address:        127.0.0.1#53

    ehowstuff.local nameserver = ns.ehowstuff.local.

ehowstuff.local nameserver = ns.ehowstuff.local.