Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a problem in network sharing using SMB protocol. I think it's related to IP-duplicating issue. How to detect this.
Note: I'm using Ubuntu on my desktop the other are using various OSs (win xp, vista, mac, Ubuntu).

share|improve this question
The original problem that I can't open WindowsShare through network. The problem source couldn't be determined, Anyway I jumped over it through a single command line to open the WindowsShare in Ubuntu. For curious people, it was: "nautilus smb://sit.local/" while sit.local is the domain-name of a network-shared Maxtor hard-disk-drive. – Omar Dolaimy Sep 29 '09 at 12:33
up vote 7 down vote accepted

You can use arpping command. The arping utility performs an action similar to ping command, but at the Ethernet layer. You can send ARP REQUEST to a neighbor host / computers.

Send ARP request
find out reachability of an IP on the local Ethernet with arping i.e send ARP request

$ sudo arping -I eth0 -c 3


ARPING from ra0
Unicast reply from [00:18:39:6A:C6:8B]  2.232ms
Unicast reply from [00:18:39:6A:C6:8B]  1.952ms
Sent 3 probes (1 broadcast(s))
Received 3 response(s)


  • -I eth0 : Specify network interface i.e. name of network device where to send ARP REQUEST packets. This option is required.
  • -c 3 : Stop after sending 3 ARP REQUEST packets

    Find duplicate IP
    The -D option specifies duplicate address detection mode (DAD). It returns exit status 0, if DAD succeeded i.e. no replies are received.

    $ sudo arping -D -I eth0 -c 2

    If duplicated you should see zero exit status:

    $ echo $?

    Always use following syntax for duplicate address detection with arping:

    $ sudo arping -D -I <interface-name> -c 2 <IP-ADDRESS-TO-TEST>
    $ echo $?
  • share|improve this answer
    There was no IP duplication!, And the original problem was solved. – Omar Dolaimy Sep 29 '09 at 12:29
    @Omar Anytime dude – admintech Sep 29 '09 at 12:29

    You can install IPwatchD which works with (other) Debian packages.
    The linked article also explains the method and installation steps.
    IPwatchD source is from sourceforge.

    alt text

    It lets you configure for a GUI notification (as above, only for GNOME) and a 'syslog' message.

    share|improve this answer
    Nice! Really useful for us, since many of our desktop PCs are running Linux – jap1968 Nov 20 '15 at 10:08

    You cannot have two machines on the same network with the same IP address.

    That said, one of the easiest ways to find out which computers have what IP address is to look through the status pages on your router. Typically there will be some kind of DHCP client list which can tell you which computer (usually given by MAC address) has what IP. One note though, if you are using DHCP, you likely do not have an IP addressing issue. What makes you think you have an IP-duplicating issue?

    share|improve this answer
    Well, you -can- have 2 machines with the same IP, but neither will work. It's annoying, and one of the main reasons I used DHCP now. – Phoshi Sep 29 '09 at 12:10
    Yes you can.... – w4etwetewtwet Jul 3 '13 at 11:04

    Your Answer


    By posting your answer, you agree to the privacy policy and terms of service.

    Not the answer you're looking for? Browse other questions tagged or ask your own question.