Solved

Hostname /IP address in Linux

Posted on 2014-03-03
6
387 Views
Last Modified: 2014-03-18
I have ubuntu server. The network interfaces is set up for DHCP
when I run Ifconfig, I see the interface gets IP 172.16.27.193 as shown in the screenshot
however when I run nslookup hostname, the Ip address is 172.16.27.20

I am not sure why those 2 IPs are different:
172.16.27.193 and 172.16.27.20

Thanks:

ipipip
0
Comment
Question by:jskfan
[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
6 Comments
 

Author Comment

by:jskfan
ID: 39902203
ip
0
 
LVL 48

Assisted Solution

by:Tintin
Tintin earned 125 total points
ID: 39902269
DHCP and DNS are two difference services, which may or may not be linked.

In your case, your DNS is giving you incorrect information, so you need to find out more about how DNS is configured in your network and how it is controlled.
0
 
LVL 18

Assisted Solution

by:TobiasHolm
TobiasHolm earned 125 total points
ID: 39902416
What Tintin says is true. Also, your reverse lookup isn't working (in-addr.arpa).

A tip is to try and use FQDN while troubleshooting, example: ubuntu.mydomain.com unstead of just ubuntu.

A good tool when troubleshooting DNS are "dig".  And also the tool "nslookup".
0
Learn by Doing. Anytime. Anywhere.

Do you like to learn by doing?
Our labs and exercises give you the chance to do just that: Learn by performing actions on real environments.

Hands-on, scenario-based labs give you experience on real environments provided by us so you don't have to worry about breaking anything.

 
LVL 13

Assisted Solution

by:Sandy
Sandy earned 125 total points
ID: 39902571
Check with Reverse DNS entries in your nameserver to understand why these 2 IP's are showing two different names. Whether nslookup or dig -x both will try to query to in-addr.arpa withing RDNS so i suggest below action plan.

1. Check and configure reverse dns in your network.
2. Configure your ubuntu box with that dns address in /etc/resolv.conf
3. Then try to test by using #nslookup <ip> or #dig -x <ip>

TY/SA
0
 
LVL 27

Accepted Solution

by:
skullnobrains earned 125 total points
ID: 39912179
you are asking the dns server at 172.16.27.2 to answer to a dns query for ubuntu.X where X is whatever is configured in the "search" line of your /etc/resolv.conf

if you expect dns and dhcp to be linked, you'd probably should use  single server for both. what is your dhcp software ? is it on the same host as the dns server ?

you probably should try and give a name that is a little more unique than ubuntu to your machine if you expect to debug anything
0
 

Author Closing Comment

by:jskfan
ID: 39937724
I will check it later…Thank you Guys!
0

Featured Post

WordPress Tutorial 4: Recommended Plugins

Now that you have WordPress installed, understand the interface, and know how to install new parts, let’s take a look at our recommended plugins.

Question has a verified solution.

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

This article will explain how to establish a SSH connection to Ubuntu through the firewall and using a different port other then 22. I have set up a Ubuntu virtual machine in Virtualbox and I am running a Windows 7 workstation. From the Ubuntu vi…
The purpose of this article is to demonstrate how we can upgrade Python from version 2.7.6 to Python 2.7.10 on the Linux Mint operating system. I am using an Oracle Virtual Box where I have installed Linux Mint operating system version 17.2. Once yo…
Learn how to find files with the shell using the find and locate commands. Use locate to find a needle in a haystack.: With locate, check if the file still exists.: Use find to get the actual location of the file.:
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
Suggested Courses

615 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