Triggering operating mode conversion for PIM protocol from sparse to dense

This article discusses two configuration knobs used to trigger the conversion of operating mode for the PIM protocol from sparse to dense.

The default operating mode for the PIM protocol is sparse mode. For this reason, when a multicast stream is received on an interface operating in sparse-dense mode, the stream will be forwarded by means of sparse mode rules unless one of the following conditions is met:

  • The dense-groups configuration specifies that the multicast group should operate in dense mode, or
  • The downstream interface for the received multicast stream is configured as dense mode.

Note that configuring downstream interface in dense mode after the multicast stream is received will not trigger the mode conversion from sparse to dense. In this case, the PIM protocol must be restarted after the knob is configured. In contrast, the dense-groups configuration will trigger the conversion even if the knob is configured after the multicast stream is received.

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Prasanna

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