as a web admin myself, i sometimes need to troubleshoot my customer's website, and so one of the many commands i use frequently is the nslookup command and the host command in linux. if you are an admin, its important to know them both. if you want to know the dns and or ip information for a domain name you can do the host or the nslookup command

LINUX:
command: host

example. here i am going to do this command for yahoo
[root@ ~]# host yahoo.com
yahoo.com has address 66.94.234.13
yahoo.com has address 216.109.112.135
yahoo.com mail is handled by 1 f.mx.mail.yahoo.com.
yahoo.com mail is handled by 1 g.mx.mail.yahoo.com.
yahoo.com mail is handled by 1 a.mx.mail.yahoo.com.
yahoo.com mail is handled by 1 b.mx.mail.yahoo.com.
yahoo.com mail is handled by 1 c.mx.mail.yahoo.com.
yahoo.com mail is handled by 1 d.mx.mail.yahoo.com.
yahoo.com mail is handled by 1 e.mx.mail.yahoo.com.


[root@ ~]# host www.yahoo.com
www.yahoo.com is an alias for www.yahoo-ht3.akadns.net.
www.yahoo-ht3.akadns.net has address 209.131.36.158



WINDOWS:
command: nslookup

C:\Documents and Settings\laptop>nslookup yahoo.com
Server: linksys.linksys
Address: 192.168.1.1

DNS request timed out.
timeout was 2 seconds.
Non-authoritative answer:
Name: yahoo.com
Addresses: 66.94.234.13, 216.109.112.135


i hope this helps. if you ever need linux or windows web hosting, visit www.webune.com they have excellent services.