Looking Up Domains and Hosts with Nslookup
CS 3000 -- Lab Assignment #6
DIRECTIONS: Before you start, scan the man page for nslookup.
When you do the lab, type nslookup commands equivalent to the ones
you see typed below, and examine the output. Ask questions.
/* Start interactive nslookup. */
john@alcyone: nslookup
Default Server: www.cs.csustan.edu
Address: 130.17.70.35
/* Select the primary nameserver at Cal Tech. I got the
domain name of the server by entering caltech.edu
at this site. */
> server mercutio.ni.caltech.edu
Default Server: mercutio.ni.caltech.edu
Address: 131.215.254.99
/* Enter a host names we got from a web search. See if the nameserver
gives a translation to an IP number. */
> www.cs.caltech.edu
Server: mercutio.ni.caltech.edu
Address: 131.215.254.99
Name: whirlwind.cs.caltech.edu
Address: 131.215.44.115
Aliases: www.cs.caltech.edu
>
/* Tell nslookup you want to get info about mail hubs for hosts. */
> set querytype=MX
/* Get info about this host. */
> squid.cs.caltech.edu
Server: mercutio.ni.caltech.edu
Address: 131.215.254.99
cs.caltech.edu
origin = namae.cs.caltech.edu
mail addr = hostmaster.cs.caltech.edu
serial = 10091950
refresh = 43200 (12H)
retry = 3600 (1H)
expire = 3628800 (6W)
minimum ttl = 3600 (1H)
>
/* Ask Mercutio to give us a complete list of all the hosts
in its database for the domain cs.caltech.edu. */
> ls -d cs.caltech.edu
[mercutio.ni.caltech.edu]
$ORIGIN cs.caltech.edu.
@ 3H IN SOA namae hostmaster (
10091950 ; serial
12H ; refresh
1H ; retry
6W ; expiry
1H ) ; minimum
3H IN NS namae
3H IN NS names
3H IN NS tepid.ni.caltech.edu.
3H IN NS tybalt.caltech.edu.
3H IN NS mercutio.ni.caltech.edu.
3H IN A 131.215.44.20
3H IN MX 0 mailhost
3H IN MX 10 obento
abacus 3H IN CNAME abekas.gg.caltech.edu.
abekas 3H IN CNAME abekas.gg.caltech.edu.
above 3H IN CNAME above.ugcs.caltech.edu.
abstract 3H IN A 131.215.45.96
acapponi 3H IN A 131.215.45.28
actel 3H IN CNAME actel.pcmp.caltech.edu.
activision 3H IN A 131.215.44.11
daemon.ad 3H IN CNAME daemon
against 3H IN CNAME against.ugcs.caltech.edu.
alaincable 3H IN A 131.215.185.187
alainslaptop 3H IN A 131.215.45.129
alainsotherlaptop 3H IN A 131.215.45.6
alexei 3H IN A 131.215.45.4
altair 3H IN A 131.215.45.138
alternator 3H IN A 131.215.44.44
amanuensis 3H IN A 131.215.44.136
amber 3H IN A 131.215.45.54
amongst 3H IN CNAME amongst.ugcs.caltech.edu.
anaheim 3H IN A 131.215.44.89
ansible 3H IN A 131.215.44.137
anvil 3H IN CNAME anvil.pcmp.caltech.edu.
apoggo 3H IN CNAME apoggo.gg.caltech.edu.
apollo 3H IN CNAME apollo.gg.caltech.edu.
apple 3H IN A 131.215.45.146
appleii 3H IN A 131.215.44.18
apropos 3H IN A 131.215.45.113
aristotle 3H IN A 131.215.44.7
3H IN MX 0 mailhost
arknoid 3H IN A 131.215.45.184
around 3H IN CNAME around.ugcs.caltech.edu.
arpeggio 3H IN CNAME arpeggio.gg.caltech.edu.
ascend 3H IN A 131.215.44.71
aspen 3H IN A 131.215.45.157
asteroids 3H IN A 131.215.45.195
astride 3H IN CNAME astride.ugcs.caltech.edu.
async 3H IN CNAME async.async.caltech.edu.
atari 3H IN A 131.215.44.68
atop 3H IN CNAME atop.ugcs.caltech.edu.
babylon 3H IN CNAME epsilon3
babylon2 3H IN A 131.215.44.6
3H IN MX 0 epsilon3
backgammon 3H IN A 131.215.45.116
baroque 3H IN A 131.215.45.106
bartek-xp-host 3H IN A 131.215.45.158
battleship 3H IN A 131.215.45.141
battlezone 3H IN A 131.215.45.187
bauhaus 3H IN A 131.215.45.85
behind 3H IN CNAME behind.ugcs.caltech.edu.
below 3H IN CNAME below.ugcs.caltech.edu.
ben 3H IN A 131.215.45.56
/* There were a lot more hosts. I deleted the rest of
the information. */
/* Get back into the mode in which nslookup translates from
domain names to IP numbers. */
> set querytype=A
/* Set the current hostname to squid */
> squid.cs.caltech.edu
Server: mercutio.ni.caltech.edu
Address: 131.215.254.99
Name: squid.cs.caltech.edu
Address: 131.215.44.93
>
/* If you have a couple of minutes to kill, execute the command below
to ask who is logged on to squid */
> finger
finger: connect: Connection timed out
/* After a minute or two, the connection times out. I did a web search to
try to find a more "student oriented" machine. I came up with a host that does
respond to finger. */
> www.gps.caltech.edu
Server: mercutio.ni.caltech.edu
Address: 131.215.254.99
Name: wwwftp.gps.caltech.edu
Address: 131.215.65.167
Aliases: www.gps.caltech.edu
> finger
[wwwftp.gps.caltech.edu]
Login Name TTY Idle When Where
mlb Michael Black pts/1 1d Mon 10:06 tincan
/* See what specific information we can get about "mlb" */
> finger mlb
[wwwftp.gps.caltech.edu]
Login name: mlb In real life: Michael Black
Directory: /home/mlb Shell: /bin/tcsh
On since Apr 25 10:06:27 on pts/1 from tincan
1 day 9 hours Idle Time
New mail received Sun May 1 00:30:08 2005;
unread since Fri Apr 29 17:12:34 2005
No Plan.
/* (It takes a minute to get the response from this next command.)
Try a "generic" name to see how much information we can get: */
> finger john
[wwwftp.gps.caltech.edu]
Login name: grotz In real life: John P. Grotzinger
Directory: /home/grotz Shell: /opt/util/bin/tcsh
Never logged in.
Mail last read Thu Jan 13 07:44:52 2005
No Plan.
Login name: kinmtrcs In real life: John Walsh
Directory: /home/kinmtrcs Shell: /opt/util/bin/tcsh
Never logged in.
No unread mail
No Plan.
Login name: jholt In real life: John Holt
Directory: /home/jholt Shell: /opt/util/bin/tcsh
Never logged in.
No unread mail
Project: Everyone should believe in something...
Plan:
I believe I'll have another beer.
Login name: johna In real life: John Armstrong
Directory: /home/johna Shell: /opt/util/bin/tcsh
Never logged in.
No unread mail
Project: No project yet...
No Plan.
Login name: jtoth In real life: John Toth
Directory: /home/jtoth Shell: /opt/util/bin/tcsh
Never logged in.
Mail last read Fri Apr 29 17:03:25 2005
No Plan.
Login name: markwis In real life: John Marquis
Directory: /home/markwis Shell: /opt/util/bin/tcsh
Last login Tue Oct 2, 2001 on pts/4 from earth
Mail last read Mon Jan 10 16:25:05 2005
Plan:
To actually have a plan.
To change it every so often.
To keep hammering away at my work.
/* There were a lot more records of users. I deleted the rest of the
information. */
/* Note: Sometimes you can get more "finger information" by doing what we
did above than the information you would get by just executing the command
finger john@www.gps.caltech.edu
at a unix prompt. (Try it.) */
/* Change the nameserver. This time it is one of our department Sun
Ultra's that runs named. */
> server altair.csustan.edu
Default Server: altair.csustan.edu
Address: 130.17.70.4
>
/* Set the current hostname to POLLUX. */
> pollux
Server: altair.csustan.edu
Address: 130.17.70.4
Name: pollux.csustan.edu
Address: 130.17.70.15
>
/* Ask who is logged on to POLLUX. */
> finger
[pollux.csustan.edu]
No one logged on
/* That was kind of boring so set the current hostname to ALTAIR. */
> altair
Server: altair.csustan.edu
Address: 130.17.70.4
Name: altair.csustan.edu
Address: 130.17.70.4
>
/* Ask who is logged on to ALTAIR. */
> finger
Login Name TTY Idle When Where
vlee Van Lee console 1d Fri 13:44 :0
> exit