Duplicate IP detection

First, check that you can sudo arping:

sudo -l
you should see something like:
(root) NOPASSWD: /sbin/ifconfig, (root) /sbin/arping
then, you can issue the command
sudo /sbin/arping -D -I bond0 -c 2 10.78.1.1


to check if the IP 10.78.1.1 is mounted in 2 places.