The Address Resolution Protocol (ARP) associates hardware addresses with IP addresses. This association may change over time. Each node in the network maintains an ARP cache mapping corresponding IP and hardware addresses. A node trying to find the hardware address for an IP address that is not in its cache, broadcasts an ARP request that also contains its own IP and hardware addresses. The node with the requested IP address replies with its hardware address. What are the possible vulnerabilities for spoofing in the ARP protocol? What defences can be used against ARP spoofing?