Which multicast IP address is used for NTP?

The correct multicast IP address for Network Time Protocol (NTP) is 224.0.1.1. This address is reserved specifically for NTP broadcast traffic that devices use to synchronize their clocks. When a device needs to obtain the time, it will send a request to this multicast address, allowing it to communicate with multiple NTP servers simultaneously.

This multicast address is well-defined within the standard set of multicast addresses used for various network services. Utilizing this specific address ensures that NTP messages are efficiently delivered to all interested parties within the local network segment. As a result, devices that are configured to listen for NTP updates will respond collectively to the multicast requests and synchronize their internal clocks based on the provided time information.

In summary, 224.0.1.1 is the designated multicast address for NTP, providing a standardized method for time synchronization across devices in a network.