HP ProCurve 6200yl Multicast And Routing Manual page 107

N o t e
Defining Supported Multicast Groups. An RP in the default candidate
configuration supports the entire range of possible multicast groups. This
range is expressed as a multicast address and mask, where the mask defines
whether the address is for a single address or a range of contiguous addresses:
Multicast Mask Address Range
Address
224.0.0.0 240.0.0.0 224.0.0.0 - 239.255.255.255
An alternate way to express the above (default) address and mask is:
224.0.0.0/4
In non-default candidate configurations, an RP allows up to four ranges of
contiguous multicast groups, and/or individual multicast groups. For example:
RP Candidate Configuration Supported Range of Multicast Groups
235.0.240.0/12
235.0.0.1/28
235.0.0.128/32
235.0.0.77/32
If a given multicast group is excluded from all RPs in a given domain, then that
group will not be available to the multicast receivers connected in the domain.
For more on this topic, refer to "Configuring Candidate-RPs on PIM-SM
Routers" on page 4-37.
Candidate-RP Election. Within a PIM-SM domain, different RPs support
different multicast addresses or ranges of multicast addresses. (That is, a
given PIM-SM multicast group or range of groups is supported by only one
active RP, although other candidate RPs can also be configured with overlap-
ping or identical support.)
A candidate RP's group-prefix configuration identifies the multicast groups
the RP is enabled to support.
If multiple candidate RPs have group prefixes configured so that any of these
RPs can support a given multicast group, then the following criteria are used
to select the RP to support the group:
PIM-SM Operation and Router Types
235.0.240.1 - 235.0.255.255
235.0.0.1 - 235.0.0.15
235.0.0.128 only
235.0.0.77 only
PIM-SM (Sparse Mode)
4-15