Multicast Heartbeat

Multicast heartbeat is the ability of the Windows 2000–based router to listen for a regular multicast notification to a specified group address. Multicast heartbeat is used to verify that IP multicast connectivity is available on the network. If the heartbeat is not received within a configured amount of time, the multicast heartbeat status of the configured interface is set to inactive. To detect that the multicast heartbeat is missing, you must create a polling mechanism that periodically checks the multicast heartbeat status. If the status becomes inactive, then you can create a notification event. For more information, see the Microsoft Platform SDK link at https://windows.microsoft.com/windows2000/reskit/webresources .

For example, you could create a mechanism that sends a Simple Network Management Protocol (SNMP) trap to the configured SNMP management station when the multicast heartbeat status becomes inactive. This requires the creation of an SNMP sub-agent; the SNMP agent on the Windows 2000 router must be configured with the SNMP community name and the destination to send traps. For more information, see "Simple Network Management Protocol" in the TCP/IP Core Networking Guide .

A common protocol used for multicast heartbeat is Simple Network Time Protocol (SNTP). SNTP uses the reserved IP multicast address 224.0.1.1 and is used for time synchronization. If the source of the heartbeat traffic (the SNTP server) is strategically placed, the loss of the heartbeat indicates a problem with the IP multicast routing infrastructure. Windows 2000 includes an SNTP server called the Windows Time Synchronization service (W32Time) and an SNTP client. For more information about SNTP, see RFC 1769.

You can configure multicast heartbeat from the Multicast Heartbeat tab of the properties of the General node under IP Routing in the Routing and Remote Access snap-in.