Switching to an SPT for PIM Sparse Mode for IPv6

PIM sparse mode initiates multicast using a shared tree. You can configure PIM sparse mode to switch to an SPT when a source starts sending multicast messages, or you can prevent PIM sparse mode from switching to an SPT. Multicasting over an SPT can be more efficient than multicasting over a shared tree (see PIM Sparse Mode in Understanding PIM for IPv6 Multicast).

To specify when PIM sparse mode switches from a shared tree to an SPT:

• Issue the ipv6 pim spt-threshold command in Global Configuration mode.
  host1(config)#ipv6 pim spt-threshold 4

  The no version restores the default value, 0.

Note: You can configure multicast on IPv4 and IPv6 interfaces. For information about configuring PIM on IPv4 interfaces, see Configuring PIM for IPv4 Multicast . For information about configuring IP interfaces, see Configuring IP in the JunosE IP, IPv6, and IGP Configuration Guide. For information about configuring IPv6 interfaces, see Configuring IPv6 in the JunosE IP, IPv6, and IGP Configuration Guide.

Related Documentation

• Understanding PIM for IPv6 Multicast
• Monitoring the Threshold for Switching to the Shortest Path Tree at a PIM Designated Router for IPv6
• ipv6 pim spt-threshold