Address Resolution Protocol (ARP) is used by the client to prevent IP conflicts after obtaining the IP address.

Address Resolution Protocol (ARP)
ARP is a protocol used to map an IP address to a physical (MAC) address in a local network. It is responsible for resolving IP addresses to MAC addresses so that data packets can be properly delivered within a network.

Preventing IP Conflicts
IP conflicts occur when two devices on the same network have the same IP address. This can cause network connectivity issues and disrupt communication. To prevent IP conflicts, the client can use ARP to ensure that each IP address is unique within the network.

How ARP Works
When a client wants to send data to a specific IP address, it first checks its ARP cache to see if it already has the corresponding MAC address. If the MAC address is not found in the cache, the client sends an ARP request broadcast message to the network asking for the MAC address associated with the IP address.

The device with the requested IP address responds with its MAC address, and the client updates its ARP cache with the mapping. This allows the client to send data packets to the correct MAC address for the desired IP address.

Preventing IP Conflicts with ARP
To prevent IP conflicts, the client can use ARP to check if the IP address it wants to assign to itself is already in use by another device on the network. Before assigning an IP address to itself, the client can send an ARP request with the desired IP address.

If there is no response to the ARP request, it means that the IP address is not in use, and the client can safely assign it to itself. However, if the client receives an ARP response with a different MAC address for the requested IP address, it indicates an IP conflict. In this case, the client can choose a different IP address to avoid conflicts.

By using ARP in this way, the client can ensure that the IP address it obtains is unique within the network, preventing conflicts and maintaining proper network communication.