If i send ARP request sent to a find the MAC address of a machine in a LAN. But among the group of hosts in the LAN, two hosts having the same IP address, then how the ARP reply works.
The same situation with the RARP, if the two machines inside the LAN with same MAC address. If i send RARP request to find IP address, then how the RARP reply works.
Primarily IP address is unique within a network and MAC is unique globally and so there should not be any confusion.
But incase if multiple devices have same IP or MAC then (probably) the first ARP or RARP will be accepted as valid response. Because once a request is obtained the information is written in to kernels ARP cache and so for subsequent needs the cache will be used (till the cache expires).
