Brocade FastIron Ethernet Switch IP Multicast Configuration Guide - Manual (Page 172)

To disable embedded RP support for a specified VRF, enter the following commands.
device(config)# ipv6 router pim vrf blue
device(config-ipv6-pim-router-vrf-blue)# no rp-embedded
Syntax: [no] rp-embedded
Changing the Shortest Path Tree threshold
In a typical IPv6 PIM Sparse domain, there may be two or more paths from a designated router (DR)
for a multicast source to an IPv6 PIM group receiver:
• Path through the RP - This is the path the device uses the first time it receives traffic for an IPv6
PIM group. However, the path through the RP may not be the shortest path from the device to the
receiver.
• Shortest Path - Each IPv6 PIM Sparse router that is a DR for an IPv6 receiver calculates a short
path tree (SPT) towards the source of the IPv6 multicast traffic. The first time the device
configured as an IPv6 PIM router receives a packet for an IPv6 group, it sends the packet to the
RP for that group, which in turn will forward it to all the intended DRs that have registered with the
RP. The first time the device is a recipient, it receives a packet for an IPv6 group and evaluates
the shortest path to the source and initiates a switchover to the SPT. Once the device starts
receiving data on the SPT, the device proceeds to prune itself from the RPT.
By default, the device switches from the RP to the SPT after receiving the first packet for a given IPv6
PIM Sparse group. The device maintains a separate counter for each IPv6 PIM Sparse source-group
pair.
You can change the number of packets the device receives using the RP before switching to using the
SPT.
To change the number of packets the device receives using the RP before switching to the SPT, enter
commands such as the following.
device(config)# ipv6 router pim
device(config-ipv6-pim-router)# spt-threshold 1000
To change the number of packets the device receives using the RP before switching to the SPT for a
specified VRF, enter commands such as the following.
device(config)# ipv6 router pim vrf blue
device(config-ipv6-pim-router-vrf-blue)# spt-threshold 1000
Syntax: [no] spt-threshold num
The num parameter specifies the number of packets. If you enter a specific number of packets, the
device does not switch over to using the SPT until it has sent the number of packets you specify using
the RP.
Setting the RP advertisement interval
To specify how frequently the candidate RP configured on the device sends candidate RP
advertisement messages to the BSR, enter commands such as the following.
device(config)# ipv6 router pim
device(config-ipv6-pim-router)# rp-adv-interval 180
Changing the Shortest Path Tree threshold
170 FastIron Ethernet Switch IP Multicast Configuration Guide
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