HP 3500YL - Manual (Page 119)

PIM-SM (Sparse Mode)
PIM-SM Operation and Router Types
Note that the routers requesting multicast traffic are either edge routers
directly connected to specific multicast receivers using IGMP to request the
traffic, or are intermediate routers on the path between the edge routers and
the RP. This operation forms an RP Tree (RPT) where only the destination
multicast address appears in the RP routing table. This is represented as
follows:
( *, G ), where:
* = a variable (wildcard) representing the IP address of any multicast
source
G = a particular multicast group address.
The software supports up to 100 RPs in a given PIM-SM domain.
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
Address Mask Address Range
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
235.0.240.0/12 235.0.240.1 - 235.0.255.255
235.0.0.1/28 235.0.0.1 - 235.0.0.15
235.0.0.128/32 235.0.0.128 only
235.0.0.77/32 235.0.0.77 only
N o t e 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.
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