ARPvastauksella

ARPvastauksella, also known as Address Resolution Protocol (ARP) reply, is a fundamental component of the Internet Protocol (IP) suite, used to map IP addresses to MAC addresses within a local network. When a device on a network needs to communicate with another device, it first checks its ARP cache to see if it already has the MAC address associated with the target IP address. If the MAC address is not found, the device sends an ARP request broadcast to the entire network, asking which device has the target IP address.

The device with the matching IP address responds with an ARP reply, which includes its MAC address. This reply is unicast back to the requesting device, allowing it to update its ARP cache and establish communication. ARP replies are essential for the proper functioning of local area networks (LANs), as they enable devices to resolve IP addresses to MAC addresses, facilitating data transmission.

ARP replies are part of the dynamic nature of ARP, which continuously updates its cache to reflect changes in the network topology. This dynamic process ensures that devices can adapt to changes, such as new devices joining the network or existing devices changing their IP addresses. The ARP cache has a finite lifespan, typically around 20 minutes, after which entries are considered stale and may be removed or refreshed through new ARP requests and replies.