[ot] same ip, different subnet mask.

a question: is possible to have two host with the same IP and different
SUBNET MASK into a LAN?

Someone said me it works in practice, but not in theory. Is it right?

Tank you very much!

On Mar 5, 2:45 pm, slystoner <slysto...@gmail.com> wrote:

> a question: is possible to have two host with the same IP and different
> SUBNET MASK into a LAN?

You can certainly do it. Whether or not it will work depends upon what
you need to happen.

> Someone said me it works in practice, but not in theory. Is it right?

It depends what you mean by "works". Something will certainly happen,
and if that's what you wanted, then it worked. If not, then not.

DS

On 03/06/2007 04:15 AM, slystoner wrote:
> a question: is possible to have two host with the same IP and different
> SUBNET MASK into a LAN?
>
> Someone said me it works in practice, but not in theory. Is it right?

IMHO, the IP, most of other such protocols and basically computers are
based on discrete integer mathematics. Hence, the theory and practice
should be one and the same anyway.

Moreover, I don't find any reason to assign same IP address to more than
one machine live on a LAN. If I'm not wrong all subnets are somehow part
of a net and, or supernet, though these may be on different LAN segments.

BTW, Is it possible you and, or that someone will let us know what you
are trying to accomplish?

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On Mon, 05 Mar 2007, in the Usenet newsgroup comp.os.linux.networking, in
article <45ec9d4f$0$10617$(E-Mail Removed)>, slystoner wrote:

>a question: is possible to have two host with the same IP and different
>SUBNET MASK into a LAN?

Is it "possible"? Sure. Practical? Probably not. Why not try it
yourself and see?

>Someone said me it works in practice, but not in theory. Is it right?

Depends on the IP stack, and how the network is _otherwise_ configured.
You _could_ set the network to not use ARP, and things might then sorta
work maybe, depending on how the static ARP entries on every system on
the local segment were configured. But otherwise you are going to have
problems. ARP doesn't have network mask values, and merely asks who
owns an address. With two hosts having the same IP, both would reply.
See RFC0826 for details - it's not that big of a document:

0826 Ethernet Address Resolution Protocol: Or converting network
protocol addresses to 48.bit Ethernet address for transmission on
Ethernet hardware. David C. Plummer. November 1982. (Format:
TXT=21556 bytes) (Also STD0037) (Status: STANDARD)

Certainly a different question, I must admit.

Old guy