Linux doesn’t do an active monitoring or reporting of duplicate ip, after the interface is initialized. To check for duplicate IP addresses in Linux:
Log into your server via console and from the command line run
arping -D -q -I eth0 -c 2 192.168.1.250 ; echo $?
If the above commands return 0, then no one responded to your arp request and therefore no one else is using your IP address.
References:
https://access.redhat.com/solutions/35057
http://www.cyberciti.biz/faq/linux-duplicate-address-detection-with-arping/