Passive Multicast Route Insertion (Pmri); Configuring Pmri; Displaying Hardware-Drop - Dell PowerConnect B-RX Configuration Manual

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Passive Multicast Route Insertion (PMRI)

Passive Multicast Route Insertion (PMRI)
To prevent unwanted multicast traffic from being sent to the CPU, Passive Multicast Route Insertion
(PMRI) can be used together to ensure that multicast streams are only forwarded out ports with
interested receivers and unwanted traffic is dropped in hardware on Layer 3 Switches. This feature
does not apply to DVMRP traffic.
PMRI enables a Layer 3 switch running PIM to create an entry for a multicast route (e.g., (S,G)), with
no directly attached clients or when connected to another PIM router (transit network).
When a multicast stream has no output interfaces, the Layer 3 Switch can drop packets in
hardware if the multicast traffic meets either of the following conditions.
In PIM-SM
In PIM-DM
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 aging processing when the traffic stops.

Configuring PMRI

PMRI is enabled by default. To disable PMRI, enter commands such as the following.
BigIron RX(config)#router pim
BigIron RX(config-pim-router)#hardware-drop-disable
Syntax: [no] hardware-drop-disable

Displaying hardware-drop

Use the show ip pim sparse command to display if the hardware-drop feature has been enabled or
disabled.
BigIron RX(config)#show ip pim sparse
Global PIM Sparse Mode Settings
Hello interval
Bootstrap Msg interval: 60
Join/Prune interval
Inactivity interval
Hardware Drop Enabled : Yes
Syntax: show ip pim sparse
584
•
The route has no OIF and
•
If directly connected source passed source RPF check and completed data registration
with RP or
•
If non directly connected source passed source RPF check.
•
The route has no OIF and
•
passed source RPF check and
•
Router has no downstream PIM neighbor.
: 30
: 60
: 180
Neighbor timeout
Candidate-RP Advertisement interval: 60
SPT Threshold
SSM Enabled
BigIron RX Series Configuration Guide
: 105
: 1
: No
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