All things related to multicast

[Bill Fenner <>]

>Why there is so big discrepancy in the Prune-holdtime timers between DVMRP
>and PIM-DM? It seems to me that PIM-DM performs worse than DVMRP regarding
>the amount and frequency of flooding.

DVMRP builds a broadcast tree with its route exchange mechanism; when this
tree changes it can tell because of the route updates and cancel prunes on
appropriate branches, etc.  PIM-DM has no route exchange mechanism and
uses flooded packets to build the multicast tree, thus to adapt to topology
changes PIM-DM has to flood on the kind of timescale that you would like
to adapt.

  Bill