ipv6 pim6-dense ttl-threshold


ipv6 pim6-dense ttl-threshold <THRESHOLD-VALUE>

no ipv6 pim6-dense ttl-threshold


Configures the multicast datagram time-to-live (router hop-count) threshold for the interface. Any IP multicast datagrams or state-refresh packets with a TTL less than this threshold will not be forwarded out the interface.

The no form of this command removes the currently configured value and sets to the default of 3 attempts.

Command context






Specifies the time to live threshold. Default: 3 attempts. Range: 0-255.


Administrators or local user group members with execution rights for this command.


The VLAN connected to the multicast source does not receive state refresh packets and thus is not state-refresh capable. Downstream VLANs in the switches are state-refresh capable. This parameter provides a method for containing multicast traffic within a network, or even within specific areas of a network. Initially, the multicast traffic source sets a TTL value in the packets it transmits. Each time one of these packets passes through a multicast routing device, the TTL setting decrements by 1. If the packet arrives with a TTL lower than the ttl-threshold, the routing switch does not forward the packet. The following aspects of the TTL setting of incoming multicast packets must be considered, before changing this parameter on a routing switch:
  • A value that is too high will allow multicast traffic to go beyond the internal network.

  • A value that is too low may prevent some intended hosts from receiving the desired multicast traffic.

  • A value of 0 will forward multicast traffic regardless of the packet TTL setting.


Configuring and removing the time to live threshold:

switch(config)# interface vlan40
switch(config-if-vlan)# ipv6 pim6-dense ttl-threshold 8
switch(config-if-vlan)# no ipv6 pim6-dense ttl-threshold