D-Link DES-6300, User Manual, Page: 202 / 298

Modular L3 Ethernet Switch User’s Guide
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Figure 6- 151. PIM IPM Route Table window
The
PIM IPM Route Table displays the following fields:
Group – Specifies the IP address of the multicast group. The range is 244.0.0.0-
239.255.255.255.
Source – Specifies the source IP address from where the multicast packets are
being sent.
Source Mask – Mask all or part of the source IP address.
Upstream Assert Timer – Indicates the time before the router reverts from its
upstream router to its RPF neighbor. When a multicast packet is received, the
router sends an assert packet on a subnet indicating what metrics were used to
reach the packet’s source address. The router with the best metrics becomes the
forwarding router. All other upstream routes are pruned. The downstream routers
also compare if the RPF with the forwarding router. This ensures that the
downstream routers send their prunes and grafts to the correct neighbor. The
forwarding router sends an assert message to notify the other routers that it is the
forwarding router. Downstream routers select the upstream router with the smallest
metrics as their RPF neighbor. If two routers have the same metrics, the router
with the highest IP address is chosen. When the assert timer expires, the
downstream may switch from the forwarding router to a RPF neighbor. A value of
0 indicates that the assert has not changed the upstream neighbor to a RPF
neighbor.
AssertMetric – Specifies the metrics advertised by the forwarding router. A value
of 0 indicates that no assert was received.
Assert MetricPref – Indicates the preference advertised by the forwarding router
on the upstream interface. Asset MetricPref is used when upstream routers are
running different Unicast protocols. A value of 0 indicates that no assert is in
effect.
Assert RPT Bit – Indicates the value of the RPT bit advertised by the forwarding
router
Flags – Specifies the PIM-specific flags pertaining to the multicast state entry.