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: altair.csustan.edu
Address: 130.17.1.50
/* Select the primary nameserver at Cal Tech.
We got the domain name while doing a previous lab (whois).
We used the command:
whois -h whois.networksolutions.com caltech.edu */
> server MERCUTIO.NI.CALTECH.EDU
Default Server: MERCUTIO.NI.CALTECH.EDU
Address: 131.215.254.99
/* Enter one of the host names we got from using the command:
whois -h whois.networksolutions.com \*caltech.edu */
See if the nameserver gives a translation to an IP number. */
> CSVAX.CS.CALTECH.EDU
Server: MERCUTIO.NI.CALTECH.EDU
Address: 131.215.254.99
Name: CSVAX.CS.CALTECH.EDU
Address: 131.215.131.131
/* Tell nslookup you want to get info about mail hubs for hosts. */
> set querytype=MX
/* Get info about this host. */
> CSVAX.CS.CALTECH.EDU
Server: MERCUTIO.NI.CALTECH.EDU
Address: 131.215.254.99
/* We find out that vlsi.cs.caltech.edu and
CSVAX.CS.CALTECH.EDU are designated mail hubs for mail
addressed to CSVAX.CS.CALTECH.EDU. The hub with the higher
preference (lower number) will be tried first. */
CSVAX.CS.CALTECH.EDU preference = 10, mail exchanger = vlsi.cs.caltech.edu
CSVAX.CS.CALTECH.EDU preference = 0, mail exchanger = CSVAX.CS.CALTECH.EDU
cs.caltech.edu nameserver = CSVAX.CS.CALTECH.EDU
cs.caltech.edu nameserver = vlsi.cs.caltech.edu
cs.caltech.edu nameserver = mercutio.ni.caltech.edu
cs.caltech.edu nameserver = tepid.ni.caltech.edu
cs.caltech.edu nameserver = tybalt.caltech.edu
vlsi.cs.caltech.edu internet address = 131.215.131.129
CSVAX.CS.CALTECH.EDU internet address = 131.215.131.131
mercutio.ni.caltech.edu internet address = 131.215.254.99
tepid.ni.caltech.edu internet address = 131.215.254.100
tybalt.caltech.edu internet address = 131.215.139.100
/* 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]
1H IN SOA csvax hostmaster (
10091158 ; serial
12H ; refresh
1H ; retry
6W ; expiry
1H ) ; minimum
1H IN NS csvax
1H IN NS vlsi
1H IN NS mercutio.ni.caltech.edu.
1H IN NS tepid.ni.caltech.edu.
1H IN NS tybalt.caltech.edu.
1H IN MX 10 vlsi
1H IN MX 0 csvax
1H IN A 131.215.131.131
sol 1H IN A 131.215.131.144
1H IN HINFO "sun-2/170" "SunOS"
a 1H IN CNAME ariadne
mani-ce 1H IN A 131.215.44.49
1H IN MX 0 smtp
1H IN HINFO "NEC MobilePro 800" "CE"
byk 1H IN HINFO "NT" "machine"
1H IN A 131.215.44.32
donald 1H IN CNAME donald.gg.caltech.edu.
pshome 1H IN A 131.215.131.12
c 1H IN CNAME centauri
z-ha-dum-vpc 1H IN A 131.215.44.33
1H IN MX 0 @
d 1H IN CNAME dogmatix
tethys 1H IN A 131.215.131.46
1H IN MX 0 vlsi
cit-adel 1H IN CNAME citadel
arvocsnet 1H IN A 131.215.131.15
ascend 1H IN A 131.215.44.71
1H IN HINFO "tracker" "unknown"
chopin 1H IN A 131.215.131.58
1H IN HINFO "Toshiba" "Win95"
SMudd-RSM-44 1H IN A 131.215.44.253
g 1H IN CNAME guitar
baton 1H IN CNAME maestro
spica 1H IN A 131.215.44.9
1H IN HINFO "PC" "linux"
h 1H IN CNAME harpsichord
hub 1H IN A 131.215.131.51
1H IN MX 0 @
i 1H IN CNAME impedimenta
emerald 1H IN MX 0 @
1H IN HINFO "SGI-Octane" "IRIX6.5"
1H IN A 131.215.44.19
bassoon 1H IN HINFO "P5/120" "BSD"
1H IN MX 0 csvax
1H IN A 131.215.78.25
/* 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 CSVAX */
> CSVAX.CS.CALTECH.EDU
Server: MERCUTIO.NI.CALTECH.EDU
Address: 131.215.254.99
Name: CSVAX.CS.CALTECH.EDU
Address: 131.215.131.131
/* Ask who is logged on to CSVAX */
> finger
[CSVAX.CS.CALTECH.EDU]
User Real Name What Idle TTY Host Console Location
adam Adam Rifkin 0:27 *p0 picasso (131.215.138.63)
bond Alan Bond 3 days *q0 varese (manchester.cs.ca)
casteel Andrew M. Casteel 1:13 *p3 varese (parsley.cacr.cal)
huny Hunyue Yau 0:03 p1 csvax (varese.cs.caltec)
huny Hunyue Yau *p1 varese (w242.z208176134.)
jia Jia Mao 3:05 *p1 rubens (131.215.82.182:0)
jlm Jacob L. Mandelson 1:25 *p0 recorder (eta-ex1.ghs.com)
matta Matt Ashton 3 days *p0 lute (antigen.cs.calte)
mika Mika Nystroem 2 days *pf varese (dogmatix.cs.calt)
mika Mika Nystroem 6:47 p3 csvax (varese.cs.caltec)
yrliu Yurun Liu 0:47 *p2 chagall (:0.0)
/* See what specific information we can get about Adam Rifkin */
> finger adam
[CSVAX.CS.CALTECH.EDU]
Adam Rifkin (adam)
Home: /ufs/wlp/adam
Shell: /usr/local/etc/tcsh
Mail forwarded to adam@vlsi.cs.caltech.edu.
User Real Name What Idle TTY Host Console Location
adam Adam Rifkin 0:27 *p0 picasso (131.215.138.63)
Plan:
Thwart the exceptional. Concentrate the wealth. Answer prayer, but late, and
without attention to detail. Intervene in a manner that suggests you haven't
been following the story. Break up the Beatles. Let good things happen to bad
people. Let bad behavior be mistaken for talent. Require compromise. Create
gossip, infection, butter. Make toilets in Europe difficult to flush.
Encourage Andy Rooney. Give people hormones before they have completed
their educations. Create the impression that hair color determines
personality. Make people wait for long periods of time, often under
fluorescent lighting. Let the shrinking of elderly people's bodies coincide
with their sudden desire to own very large cars. Let there be berets. Let
there be child performers. Let there be autobiography. Let there be Cher.
(from Henry Alford, New York Times Sunday Magazine, 5 February 1995)
--------------------------------------------------------------------------
work address: Caltech Mail Stop 256-80, Pasadena, CA 91125-5222.
home address: 285 West California #11, Pasadena, CA 91105.
phone home: (626) 449-4123, work: (626) 395-4840, fax: (626) 792-4257.
--------------------------------------------------------------------------
*
/* Note: the information we got above is quite a bit more
than what we could get just from typing "finger
adam@csvax.cs.caltech.edu" at a unix prompt. */
/* Change the nameserver. This time it is one of our
department NeXT's that runs named. */
> server csustan.csustan.edu
Default Server: csustan.csustan.edu
Address: 130.17.1.70
/* Set the current hostname to POLLUX. */
> pollux
Server: csustan.csustan.edu
Address: 130.17.1.70
Name: pollux.csustan.edu
Address: 130.17.1.55
/* Ask who is logged on to POLLUX. */
> finger
[pollux.csustan.edu]
Login Name TTY Idle When Where
amb Amberse Banks pts/6 1 Sat 21:51 kali.csustan.edu
> exit