We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you a podcast all about Citrix Workspace, moving to the cloud, and analytics & intelligence. Episode 2 coming soon!Listen Now

x

Same IP Address

Shabzt
Shabzt asked
on
Medium Priority
432 Views
Last Modified: 2010-03-19
How can in one network we have same ip address of two or more than two network devices? What can be the problems?
Comment
Watch Question

Erik BjersPrincipal Systems Administrator

Commented:
You can not have the same IP address on more than one device in a network.  NO WAY NO HOW.

eb

Author

Commented:
Even on diff subnet we can't have the same ip address?
Erik BjersPrincipal Systems Administrator

Commented:
on diff subnet you can
Erik BjersPrincipal Systems Administrator

Commented:
OK can you please explain in more detail what you are trying to do.  If you have the same IP in diff subnets then it's not thechnicaly the same IP or even the same network as you need routing between subnets.  But routing will not work because if a local system in one subnet trys to reach your IP that's the same in the other subnet it will not get routed.

eb

Author

Commented:
Ok thanks...

I am NMS developer n thinking of this situation

let me sum up

1. We can have same IP address on diff subnets with in one network, but we cant have same ip address on same subnet
2. Communication with those same IPs will fail, if both are up. But if one is down then it will be ok.

Is it true... or I misssed any point
Principal Systems Administrator
Commented:
OK let me see if I can figure out how to say this.

Take this example

You have host A IP 1.2.3.4 SUBNET 255.255.255.0 and and host B IP 1.2.3.4 SUBNET 255.255.0.0  Logicaly both these can exist because they are not the same IP address/ SUBNET combo.

Host A would have a network address of 1.2.3.0 and a host address of 0.0.0.4
Host B would have a network address of 1.2.0.0 and a host address of 0.0.2.3

These are technicaly on different networks.

For any comunication between subnets you need a router.  If a host in the 255.255.255.0 subnet trys to reach 1.2.3.4 the request will NOT GET ROUTED no mater what because that IP resids within the subnet of 255.255.255.0.  And the same for hosts on the 255.255.0.0 SUBNET.  And these 2 hosts WILL NOT BEABLE TO COMUNICATE WITH EACH OTHER.

So while you can technicaly do this it is not a good idea and there may be a better aproch.  if you can give a better picture of what you are trying to accomplish perhaps I can give some insight to an alternite.

eb

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts

Author

Commented:
Thanks

As I told you I am NMS developer, so this situation came to my mind that if s/w finds this condition in any network then wht should be the action. I got a good idea from your replies. If any thing you can suggest on what action a NMS should take, please let me know

Author

Commented:
On discovery or monitoring components
Steve KnightIT Consultancy
CERTIFIED EXPERT

Commented:
Sorry don't know what NMS means but It will not happen in any network and if it did you would not be able to detect it because it either a) it simply wouldn't work if they were on different physical subnets using the same range or b) if they were on the same subnet the interface on one machine would shut down when it detected the clash.

Erik BjersPrincipal Systems Administrator

Commented:
as Dragon said, I have no idea what NMS means either.  Thanks for the points.

eb

Author

Commented:
Its network management software
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.