IP, MAC address duplication detection ?

Hi, there.

In Linux box, How can I detect IP/MAC address duplication?
I'm using kernel-2.4.18 but the kernel does not seem to have
gratuitous arp implementation. Is it right?

I know I can detect IP address duplication by arping program
But I want to implment a following mechanism.

When the linux machine bootstraps or one of the nework interfaces
is assigned a MAC/IP address, the linux box can detect the duplication
of newly assigned MAC/IP address. How can I do this ?

thanks.