This is a quick tip to find duplicate IP address in your local LAN network.
To find duplicate IP address, you can use arping command under linux.
#arping -D 192.168.0.10
# arping -D 192.168.0.10 132
ARPING 192.168.0.10 from 192.168.0.2 eth0
Unicast reply from 192.168.0.10 [00:0C:29:2A:3C:C7] 0.896ms
Unicast reply from 192.168.0.10 [00:0C:29:55:B7:DB] 0.923ms
Where the option -D mean: duplicate address detection mode.
In our example there is duplicate IP address in local LAN network.