From mboxrd@z Thu Jan 1 00:00:00 1970 From: unni krishnan Subject: Duplicate IP false alerts from arping Date: Fri, 16 Apr 2010 12:21:30 +0530 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: netdev@vger.kernel.org Return-path: Received: from qw-out-2122.google.com ([74.125.92.25]:41810 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755465Ab0DPGvc (ORCPT ); Fri, 16 Apr 2010 02:51:32 -0400 Received: by qw-out-2122.google.com with SMTP id 8so741852qwh.37 for ; Thu, 15 Apr 2010 23:51:31 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Hi, I am trying to find a duplicate IP in the network using arping. ------------------------- [root@vps1 ~]# ping -c 3 192.168.1.212 PING 192.168.1.212 (192.168.1.212) 56(84) bytes of data. 64 bytes from 192.168.1.212: icmp_seq=1 ttl=64 time=1.33 ms 64 bytes from 192.168.1.212: icmp_seq=2 ttl=64 time=0.280 ms 64 bytes from 192.168.1.212: icmp_seq=3 ttl=64 time=0.306 ms --- 192.168.1.212 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 1999ms rtt min/avg/max/mdev = 0.280/0.641/1.339/0.494 ms [root@vps1 ~]# arping -D -I eth0 -c 5 192.168.1.212 ; echo $? ARPING 192.168.1.212 from 0.0.0.0 eth0 0 ------------------------- As per arping that IP is duplicate. But if I go ahead and ifdown the IP in the known location I cant ping that IP ( That means that IP is not duplicated ? ). This is the result after shutting down the IP. -------------------------- [root@vps1 ~]# ping -c 3 192.168.1.212 PING 192.168.1.212 (192.168.1.212) 56(84) bytes of data. >>From 192.168.1.63 icmp_seq=1 Destination Host Unreachable >>From 192.168.1.63 icmp_seq=2 Destination Host Unreachable >>From 192.168.1.63 icmp_seq=3 Destination Host Unreachable --- 192.168.1.212 ping statistics --- 3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2001ms , pipe 3 [root@vps1 ~]# arping -D -I eth0 -c 5 192.168.1.212 ; echo $? ARPING 192.168.1.212 from 0.0.0.0 eth0 Sent 5 probes (5 broadcast(s)) Received 0 response(s) 0 [root@vps1 ~]# -------------------------- My question is, in this case IP 192.168.1.212 is not duplicated. But still arping gives duplicate status. Why it is like that ? -- Regards, Unni http://mutexes.org/ http://twitter.com/webofunni