Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

host name look up on ip address

Posted on 2014-01-31
1
Medium Priority
?
563 Views
Last Modified: 2014-02-03
Hi,

I am trying below example.
http://www.avajava.com/tutorials/lessons/how-do-i-use-a-host-name-to-look-up-an-ip-address.html

I wonder why got out put 5 different times as below

--------------------------
Which Host:local host
Canonical Host Name:DERBIZZ
Host Name:DERBIZZ
Host Address:192.168.1.106
----------------------------------------------------
Which Host:www.google.com
Canonical Host Name:po-in-f104.google.com
Host Name:www.google.com
Host Address:72.14.253.104
----------------------------------------------------
Which Host:www.google.com #1
Canonical Host Name:po-in-f104.google.com
Host Name:www.google.com
Host Address:72.14.253.104
--------------------------
Which Host:www.google.com #2
Canonical Host Name:po-in-f103.google.com
Host Name:www.google.com
Host Address:72.14.253.103
--------------------------
Which Host:www.google.com #3
Canonical Host Name:po-in-f99.google.com
Host Name:www.google.com
Host Address:72.14.253.99
--------------------------
Which Host:www.google.com #4
Canonical Host Name:po-in-f147.google.com
Host Name:www.google.com
Host Address:72.14.253.147


what is difference between cononical host name and host name.
Just as an aside, what happens if we try doing a lookup on a host that doesn't exist, such as: InetAddress.getByName("www.this-host-does-not-exist.com")? An UnknownHostException is thrown, as shown below.

java.net.UnknownHostException: www.this-host-does-not-exist.com: www.this-host-does-not-exist.com


what is the meaning of host not exists.

please advise
Any links resources ideas highly appreciated. Thanks in advance
0
Comment
Question by:gudii9
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 14

Accepted Solution

by:
Phil Phillips earned 2000 total points
ID: 39825391
You got different a list of results because Google has it set up so that www.google.com resolves to a whole set of IPs.  This helps Google distribute their load.

In this case, the canonical hostname is the "true" hostname of each particular IP, while the hostname is the original hostname you used for your query.

As for the "host not exists", that's just an example of what happens when you query a hostname that does not resolve.
0

Featured Post

Tech or Treat!

Submit an article about your scariest tech experience—and the solution—and you’ll be automatically entered to win one of 4 fantastic tech gadgets.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Go is an acronym of golang, is a programming language developed Google in 2007. Go is a new language that is mostly in the C family, with significant input from Pascal/Modula/Oberon family. Hence Go arisen as low-level language with fast compilation…
In this post we will learn different types of Android Layout and some basics of an Android App.
Viewers learn about the “for” loop and how it works in Java. By comparing it to the while loop learned before, viewers can make the transition easily. You will learn about the formatting of the for loop as we write a program that prints even numbers…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…

610 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question