Chapter 4 Electra 9200 Specifications
HHP Support
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Electra 9200, Rev O
To prevent this scenario, enable HHP. When you enable HHP, a backup device taking over in
a redundancy switching event sends a command (over a unique multicast address on the
video IP network) to turn off the outputs of the formerly active device. During a redundancy
switch, the backup device assumes all responsibilities of the primary device, including
sending HHP messages at the same multicast address.
If a primary device detects HHP messages sent to its multicast IP address, it immediately
backs off and stops sending output. This leaves the backup device free to operate without the
primary device sending the same output.
In 1×1 hot backup configurations, the HHP protocol can also initiate a redundancy switch. In
this case, the backup device monitors the primary device by listening for HHP messages. If
the backup device does not detect an HHP message from the primary device during a
specified interval, it initiates a redundancy switch and assumes operation as the primary
device.
NOTE:
HHP and IGMP version 3 are not compatible at this time.
