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Passive multicast route insertion – Brocade FastIron Ethernet Switch IP Multicast Configuration Guide User Manual

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The vrf parameter allows you to display IP PIM counters for the VRF instance specified by the vrf-
name
variable.

The following table displays the output from the show ip pim counter nsr command.

This field...

Displays...

Mcache sync The mcache NSR sync queue that carries the NSR sync message for mcache updates.

pack

The number of NSR sync messages that are packed from the active module to the standby
module.

unpack

The number of NSR sync messages that are received and unpacked by the standby module.

ack

The number of NSR sync acknowledgements received by the active module.

RPset sync

The RPset sync queue that carries the NSR sync message for RPset update.

BSR status

The BSR status sync queue that carries the NSR sync message for BSR information update.

Passive multicast route insertion

To prevent unwanted multicast traffic from being sent to the CPU, PIM routing and passive multicast
route insertion (PMRI) can be used together to ensure that multicast streams are forwarded out only
ports with interested receivers and unwanted traffic is dropped in hardware on Layer 3 switches.

PMRI enables a Layer 3 switch running PIM Sparse to create an entry for a multicast route (for
example, (S,G)), with no directly attached clients or when connected to another PIM device (transit
network).

When a multicast stream has no output interfaces (OIF), the Layer 3 switch can drop packets in
hardware if the multicast traffic meets either of the following conditions:

In PIM-SM:

The route has no OIF and

If directly connected source passed source reverse-path forwarding (RPF) check and
completed data registration with reverse path (RP) or

If non directly connected source passed source RPF check.

In PIM-DM:

The route has no OIF and

passed source RPF check and

Device has no downstream PIM neighbor.

If the OIF is inserted after the hardware-drop entries are installed, the hardware entries will be updated
to include the OIFs.

NOTE
Disabling hardware-drop does not immediately take away existing hardware-drop entries, they will go
through the normal route aging processing when the traffic stops.

Passive multicast route insertion

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FastIron Ethernet Switch IP Multicast Configuration Guide

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