RFC 2151 (rfc2151) - Page 3 of 52

A Primer On Internet and TCP/IP Tools and Utilities

RFC 2151          Internet & TCP/IP Tools & Utilities          June 1997


   interface for different packages will be different and the actual
   command line may appear differently than shown here; this will be
   particularly true for graphical user interfaces running over Windows,
   X-Windows, OS/2, or Macintosh systems. Windows-based sessions are not
   shown in this RFC because of the desire to have a text version of
   this document; in addition, most GUI-based TCP/IP packages obscure
   some of the detail that is essential for understanding what is really
   happening when you click on a button or drag a file. The Internet has
   many exciting things to offer but standardized interfaces to the
   protocols is not yet one of them!  This guide will not provide any
   detail or motivation about the Internet Protocol Suite; more
   information about the TCP/IP protocols and related issues may be
   found in RFC 1180 [29], Comer [6], Feit [7], Kessler [14], and
   Stevens [30].

   In the descriptions below, commands are shown in a Courier font
   (Postscript and HTML versions); items appearing in square brackets
   ([]) are optional, the vertical-bar (|) means "or," parameters
   appearing with no brackets or within curly brackets ({}) are
   mandatory, and parameter names that need to be replaced with a
   specific value will be shown in italics (Postscript and HTML
   versions) or within angle brackets (, text version). In the sample
   dialogues, user input is in bold (Postscript and HTML versions) or
   denoted with asterisks (**) in the margin (text version).

3. Finding Information About Internet Hosts and Domains

   There are several tools that let you learn information about Internet
   hosts and domains. These tools provide the ability for an application
   or a user to perform host name/address reconciliation (NSLOOKUP),
   determine whether another host is up and available (PING), learn
   about another host's users (Finger), and learn the route that packets
   will take to another host (Traceroute).

3.1. NSLOOKUP

   NSLOOKUP is the name server lookup program that comes with many
   TCP/IP software packages. A user can use NSLOOKUP to examine entries
   in the Domain Name System (DNS) database that pertain to a particular
   host or domain; one common use is to determine a host system's IP
   address from its name or the host's name from its IP address. The
   general form of the command to make a single query is:

      nslookup [IP_address|host_name]

   If the program is started without any parameters, the user will be
   prompted for input; the user can enter either an IP address or host
   name at that time, and the program will respond with the name and



Kessler &  Shepard           Informational