Web sites mentioned in the class

We mentioned several web sites in the class. Here is a list:

• http://standards.ieee.org/regauth/oui/index.shtml Where to lookup ethernet address.
• http://www.ssh.com One place to get ssh.
• http://www.openssh.com Another place to get ssh.
• http://www.freessh.org One more place to get ssh.
• http://sunsolve.Sun.COM/pub-cgi/show.pl?target=patches/patch-access Access to recommended Sun patches.
• http://www.wwa.com/~razeh/HT1.html This document.

Recommended books

We mentioned two books on the course that you should consider buying. If you need to administer DNS buy DNS and BIND, 3rd Edition by Paul Albitz and Cricket Liu. For managing NIS or NFS consider Managing NFS and NIS by Hal Stern.

DNS Lab

This lab sets up a master DNS server on a machine named instructor.harper.edu. You'll want to change instructor.harper.edu to match your machine's address, and it's IP address as well.

1) Populate /etc/resolv.conf

domain harper.edu
nameserver 127.0.0.1

2) Create a directory for named

mkdir /usr/local
mkdir /usr/local/adm
mkdir /usr/local/adm/named

3) Create the local zone, in /usr/local/adm/named/db.127.0.0

0.0.127.in-addr.arpa. IN SOA instructor.harper.edu. postmaster.instructor.harper.edu. (
        1 ; serial number
        10800 ; refresh time
        3600 ; retry after 1 hour
        604800 ; expire after 1 week
        86400 ); Minimum TTL of 1 day

0.0.127.in-addr.arpa. IN NS instructor.harper.edu.

1.0.0.127.in-addr.arpa. IN PTR localhost.

4a) Create the harper zone in db.harper

harper.edu. IN SOA instructor.harper.edu. postmaster.instructor.harper.edu. (
	1 ; serial number
        10800 ; refresh time
        3600 ; retry after 1 hour
        604800 ; expire after 1 week
        86400 );

harper.edu. NS instructor.harper.edu.  ; This is a nameserver entry.

instructor.harper.edu. IN A 131.107.2.100 ; This is an address entry.
student11.harper.edu. IN A 131.107.2.111 ; This is an address entry.

4b) Now create the reverse lookup map in db.2.107.131

2.107.131.in-addr.arpa. IN SOA instructor.harper.edu. postmaster.instructor.harper.edu. (
        1 ; serial number
        10800 ; refresh time
        3600 ; retry after 1 hour
        604800 ; expire after 1 week
        86400 );

2.107.131.in-addr.arpa. IN NS instructor.harper.edu ; Who is my nameserver for this domain?

100.2.107.131.in-addr.arpa. IN PTR instructor.harper.edu.
111.2.107.131.in-addr.arpa. IN PTR student11.harper.edu.

5) Create /etc/named.conf

options {
        directory "/usr/local/adm/named";
        };

zone "0.0.127.in-addr.arpa" in {
        type master;
        file "db.127.0.0";
        };

zone "harper.edu" in {
	type master;
	file "db.harper";
	};
	
zone "2.107.131.in-addr.arpa" in {
	type master;
	file "db.2.107.131";
	};
	

6) Try running a simple nslookup for student11.

7) Try performing a telnet to student11. You should be unable to lookup the host.

8) Now fix /etc/nsswitch.conf

Examine the difference between nsswitch.conf and nsswitch.dns with diff:

diff nsswitch.dns nsswitch.conf

Now fix nsswitch.conf

cp nsswitch.dns nsswitch.conf

9) Now try performing a telnet. Now you should be able to lookup the host.

10) Try a reverse lookup with nslookup

> set type=PTR
> 131.107.2.100
Server:  localhost
Address:  127.0.0.1

100.2.107.131.in-addr.arpa      name = instructor.harper.edu
2.107.131.in-addr.arpa  nameserver = instructor.harper.edu.2.107.131.in-addr.arpa
> quit
Server:  localhost
Address:  127.0.0.1