Looking Up Domains and Hosts with Nslookup
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 tybalt.caltech.edu
Default Server: tybalt.caltech.edu
Address: 131.215.139.100
/* Enter a host name we got from a web search. See if the nameserver
gives a translation to an IP number. */
> www.cs.caltech.edu
Server: tybalt.caltech.edu
Address: 131.215.139.100
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. */
> catfish.gg.caltech.edu
Server: tybalt.caltech.edu
Address: 131.215.139.100
catfish.gg.caltech.edu canonical name = waggle.gg.caltech.edu
waggle.gg.caltech.edu preference = 10, mail exchanger = mailhost.gg.caltech.edu
gg.caltech.edu nameserver = tybalt.caltech.edu
gg.caltech.edu nameserver = druggist.gg.caltech.edu
tybalt.caltech.edu internet address = 131.215.139.100
druggist.gg.caltech.edu internet address = 131.215.129.11
>
/* Ask Tybalt to give us a complete list of all the hosts
in its database for the domain cs.caltech.edu. */
> ls -d cs.caltech.edu
[tybalt.caltech.edu]
$ORIGIN cs.caltech.edu.
@ 3H IN SOA namae hostmaster (
10092080 ; 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 snowstorm
# 3H IN MX 10 snowstorm
#\@ 3H IN MX 10 snowstorm
abacus 3H IN CNAME abekas.gg.caltech.edu.
abekas 3H IN CNAME abekas.gg.caltech.edu.
acquire 3H IN A 131.215.45.24
actel 3H IN CNAME actel.pcmp.caltech.edu.
activision 3H IN A 131.215.44.11
daemon.ad 3H IN CNAME daemon
alaincable 3H IN A 131.215.185.187
alexei 3H IN A 131.215.45.4
algebra 3H IN A 131.215.45.43
altair 3H IN A 131.215.45.138
alternator 3H IN A 131.215.44.44
amanuensis 3H IN A 131.215.44.136
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
arbitrary 3H IN A 131.215.45.130
arclight 3H IN A 131.215.44.150
arknoid 3H IN A 131.215.45.184
arpeggio 3H IN CNAME arpeggio.gg.caltech.edu.
asteroids 3H IN A 131.215.45.195
async 3H IN CNAME async.async.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
banshee 3H IN A 131.215.45.32
battleship 3H IN A 131.215.45.141
battlezone 3H IN A 131.215.45.187
bill 3H IN CNAME bill.pcmp.caltech.edu.
bill-cat 3H IN CNAME bill-cat.pcmp.caltech.edu.
bishop 3H IN A 131.215.44.175
black-hole 3H IN A 131.215.45.27
blizzard 3H IN A 131.215.44.2
3H IN MX 0 blizzard
boggus 3H IN CNAME boggus.gg.caltech.edu.
Booth-RSM-44 3H IN A 131.215.44.252
breakout 3H IN A 131.215.45.186
broadcast-44 3H IN A 131.215.44.255
broadcast-45 3H IN A 131.215.45.255
buffy 3H IN CNAME epsilon3
butterfly 3H IN A 131.215.45.131
[[ Skipped Many Entries Here ... ]]
cs24vm2 3H IN A 131.215.44.48
cs24vm3 3H IN A 131.215.44.49
cs24vm4 3H IN A 131.215.44.50
ct 3H IN A 131.215.45.63
cups 3H IN CNAME gutenberg
curtain 3H IN A 131.215.44.146
cvs 3H IN CNAME distributor
daemon 3H IN A 131.215.45.79
death 3H IN A 131.215.44.90
deep-thought 3H IN CNAME apollo.gg.caltech.edu.
deepblue 3H IN A 131.215.44.57
default-44 3H IN A 131.215.44.254
default-45 3H IN A 131.215.45.254
DHCP-44-154 3H IN A 131.215.44.154
DHCP-44-155 3H IN A 131.215.44.155
DHCP-44-177 3H IN A 131.215.44.177
DHCP-44-178 3H IN A 131.215.44.178
DHCP-44-201 3H IN A 131.215.44.201
DHCP-44-202 3H IN A 131.215.44.202
DHCP-44-203 3H IN A 131.215.44.203
DHCP-44-204 3H IN A 131.215.44.204
DHCP-44-205 3H IN A 131.215.44.205
DHCP-44-206 3H IN A 131.215.44.206
DHCP-44-207 3H IN A 131.215.44.207
[[ Skipped Many More Entries Here ... ]]
DHCP-45-243 3H IN A 131.215.45.243
DHCP-45-244 3H IN A 131.215.45.244
DHCP-45-245 3H IN A 131.215.45.245
diffeq 3H IN A 131.215.45.111
digdug 3H IN A 131.215.45.191
display74a 3H IN A 131.215.44.67
distributor 3H IN A 131.215.44.69
ditchday 3H IN CNAME epsilon3
docs 3H IN A 131.215.44.12
doggerel 3H IN CNAME doggerel.gg.caltech.edu.
donald 3H IN CNAME donald.gg.caltech.edu.
donkeykong 3H IN A 131.215.45.198
doohickey 3H IN A 131.215.45.37
doom 3H IN A 131.215.45.84
ducat 3H IN CNAME catfish.gg.caltech.edu.
dummynet-recv 3H IN A 131.215.45.155
earth 3H IN A 131.215.45.88
[[ Skipped Still More Entries Here ... ]]
wolfenstein 3H IN A 131.215.45.81
wraith 3H IN A 131.215.45.62
www 3H IN CNAME whirlwind
xiaojie 3H IN A 131.215.45.76
yiying 3H IN A 131.215.45.115
z 3H IN CNAME gorgonzola.async.caltech.edu.
zappy 3H IN A 131.215.45.56
zaxxon 3H IN A 131.215.45.192
ziggurat 3H IN CNAME ziggurat.gg.caltech.edu.
zola 3H IN CNAME gorgonzola.async.caltech.edu.
zork 3H IN A 131.215.45.85
@ 3H IN SOA namae hostmaster (
10092080 ; serial
12H ; refresh
1H ; retry
6W ; expiry
1H ) ; minimum
/* As indicated within the display above, I deleted many of the host
entries to make the display more compact. */
/* Get back into the mode in which nslookup translates from
domain names to IP numbers. */
> set querytype=A
/* Set the current hostname to catfish */
> catfish.gg.caltech.edu
Server: tybalt.caltech.edu
Address: 131.215.139.100
Name: waggle.gg.caltech.edu
Address: 131.215.129.135
Aliases: catfish.gg.caltech.edu
>
/* Execute the command below to ask who is logged on to catfish */
> finger
finger: connect: Connection refused
/* This particular machine is configured not to respond to requests that go
to the 'finger' port. I did a web search to try to get the name of a more
"student oriented" machine. I found a host that does respond to
finger. */
> its.caltech.edu
Server: tybalt.caltech.edu
Address: 131.215.139.100
Name: its.caltech.edu
Addresses: 131.215.239.44, 131.215.239.32, 131.215.239.33, 131.215.239.43
> finger
[its.caltech.edu]
Login Name TTY Idle When Where
plaster Bradley R. Plaster pts/2 1d Thu 09:01 dhcp-109-160.caltech
ashih Angela R. Shih *pts/3 2:56 Thu 20:08 dhcp-159-98.caltech.
scottr Scott A. Ross pts/5 1:28 Thu 14:44 guava.caltech.edu
mason Mason A. Porter pts/6 49 Thu 20:28 ppp-71-138-238-231.d
dljazz Dalina Thrift-Vivero *pts/7 2:13 Thu 12:13 dhcp-167-234.caltech
akelly Alex Kelly *pts/8 2:30 Thu 22:05 dhcp-101-183.caltech
jsm Jason S. Minamora pts/9 9d Tue 11:48 theory.caltech.edu
tikoo Sonia M. Tikoo *pts/11 4:59 Wed 21:57 dhcp-172-192.caltech
evroth Ellen Rothenberg *pts/12 Fri 00:33 193.205.231.8
yingkai Yingkai Ouyang pts/13 6:37 Tue 10:27 cpu105.math.uwaterlo
fu Daniel Xun Fu *pts/16 1:50 Mon 08:11 dhcp-158-191.caltech
atiya Atiya Y. Hakeem pts/21 2d Sun 20:23 24-205-74-249.dhcp.p
jack Jack Sayers pts/24 8:41 Wed 10:48 dhcp-116-210.caltech
jkerc Joseph Alan Kerckhof *pts/29 2:28 Tue 16:26 mload.caltech.edu
jenkile Jennifer Erin Kile pts/30 11: Mon 17:04 pcth06b.theory.calte
relyea David R. Relyea pts/31 5 Thu 15:46 64.128-200-78.static
zifnab Joseph Schaeffer pts/33 23: Wed 13:05 bowstring.dna.caltec
apwest Anthony Paul West pts/34 9 Thu 22:35 pix-1.caltech.edu
yuan Yuan Gong *pts/35 19 Thu 08:23 dhcp-166-180.caltech
erich Erich Schneider pts/36 6:48 Wed 12:57 fw-dip4.burbank.corp
ilya Ilya Mandel pts/37 3d Wed 19:54 tweedlebeetle.tapir.
caglar Ismet Caglar Tanriku *pts/43 5:34 Thu 10:50 elma.che.caltech.edu
donde Donde R. Anderson pts/44 20 Fri 00:13 66-215-92-238.dhcp.p
jamesk James Alan Karnesky *pts/45 6:49 Wed 14:44 berthelot.galcit.cal
birdwalk Caltech Bird Walks pts/51 3d Wed 14:18 valkyr.srl.caltech.e
atiya Atiya Y. Hakeem pts/54 10: Thu 13:40 aotus.bio.caltech.ed
riley Riley Lynn Franks *pts/56 2:48 Thu 14:12 dhcp-170-105.caltech
/* See what specific information we can get about "birdwalk" */
> finger birdwalk
[its.caltech.edu]
Login name: birdwalk In real life: Caltech Bird Walks
Directory: /home/birdwalk Shell: /usr/local/bin/tcsh
Last login Wed Nov 14 15:25 on pts/65 from valkyr.srl.calt
No unread mail
No Plan.
/* (It may take a while to get the response from this next command.) Try a
"generic" name to see how much information we can get: */
> finger mcbride
[its.caltech.edu]
Login name: smcbride In real life: Sara W. McBride
Directory: /home/smcbride Shell: /usr/local/bin/tcsh
Never logged in.
No unread mail
No Plan.
Login name: mcbride In real life: K. C. McBride
Directory: /home/mcbride Shell: /bin/csh
Never logged in.
No unread mail
No Plan.
/* Depending on the name you search for, you can get a large amount of
output from a command like the one above. For example, try "finger john" */
/* 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 mcbride@its.caltech.edu
at a unix prompt. */
/* 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 SHALIM. */
> shalim
Server: altair.csustan.edu
Address: 130.17.70.4
Name: shalim.csustan.edu
Address: 130.17.70.3
>
/* Ask who is logged on to SHALIM. */
> finger
[shalim.csustan.edu]
Login Name TTY Idle When Where
julie Julie D. Gorman dtremote 60d Sun 14:26 ra:0
> exit