[CentOS] how to find unknown ip address?

Sat Jun 1 04:09:24 UTC 2013
Ted Miller <tedlists at sbcglobal.net>

On 05/28/2013 10:04 PM, Fred Smith wrote:
> On Tue, May 28, 2013 at 08:54:03PM -0400, SilverTip257 wrote:
>> On Tue, May 28, 2013 at 6:38 PM, Kahlil Hodgson <
>> kahlil.hodgson at dealmax.com.au> wrote:
>>> Also the arpwatch program might help if you are trying to track down
>>> mysterious devices popping up on your network.
>> +1 for arpwatch
>> You beat me to mentioning it. ;)
>>> K
> <snip>
>>> On Wed, May 29, 2013 at 8:14 AM, Kahlil Hodgson <
>>> kahlil.hodgson at dealmax.com.au> wrote:
>>>> Running 'arp -n' on a machine that you think might receive packets from
>>>> the unknown host might also do the job.
>>>> K
> <snip>
> Perhaps a stupid idea: I didn't see where the OP indicated they did not
> know which physical machine this is, but I understood it to be unknown
> on the network.
> So, if I"m right, just go to the machine and do ifconfig or similar.
> Or if I'm wrong, just pretend I didn't say this! :)
You are assuming that this is a machine with a keyboard and monitor.  The 
OP did not give us that information.  I have several devices on my network 
without user interfaces, like a TV tuner.  It has no input device -- I 
don't think it even has a power switch.  I has three wires going in the 
back -- power, antenna, network.  Exactly how am I going to ask it 
ifconfig?  Even a router or firewall can be a mystery as to what IP address 
it will respond to.

Read carefully, and don't impose your network on the OP's situation.

Ted Miller
Elkhart, IN, USA