Asante Technologies 35516 - Manual (Page 80)

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5.9.2 Change IRDP Parameters
When IRDP processing is enabled, the default parameters will apply. You may change any of the following default
parameters. Use the following commands in interface configuration mode.
Command Purpose
ip irdp multicast Send IRDP advertisements to the all-systems multicast
address (224.0.0.1) on a specified interface.
ip irdp holdtime seconds Set the IRDP period for which advertisements are valid.
ip irdp maxadvertinterval seconds Set the IRDP maximum interval between advertisements.
ip irdp minadvertinterval seconds Set the IRDP minimum interval between advertisements.
Ip irdp preference number Set a device’s IRDP preference level.
5. 10 Configuring Protocol-Independent Multicast Protocol (PIM)
The IC35516 supports PIM as specified in IETF RFC 2362. PIM can operate in dense mode or sparse mode. In PIM
sparse mode, a multicast router (IC35516) assumes that other multicast routers do not have any receivers for a group
until there is an explicit request for that group. When hosts join a multicast group, the directly-connected routers send
PIM Join messages toward the rendezvous point (RP). The RP keeps track of multicast groups. Hosts that send
multicast packets are registered with the RP by that host’s immediate multicast router. The RP then sends Join
messages toward the source. At this point, packets are forwarded on a shared distribution tree. If the multicast traffic
from a specific source is sufficient, the receiver’s immediate router may send Join messages toward the source to
build a source-based distribution tree.
PIM uses the Bootstrap Router (BSR) to discover and announce RP-set information for each group prefix to all the
routers in a PIM domain. To avoid a single point of failure, there are usually several candidate BSRs in a PIM domain.
A BSR is elected from the candidate BSRs automatically, using bootstrap messages to discover which BSR has the
highest priority. This router then announces to all PIM routers in the PIM domain that it is the BSR. Routers that are
configured as candidate RPs then unicast to the BSR the group range for which they are responsible. The BSR
includes this information in its bootstrap messages and announces it to all PIM routers in the domain. Based on this
information, all routers can map multicast groups to specific RPs. As long as a router is receiving the bootstrap
message, it has a recent RP-set.
5.10.1 Enabling PIM Sparse Mode
Use the ip pim sparse mode global configuration command to enable PIM and operate in sparse mode.
5.10.2 Setting Up BSR Candidacy
Use the following global configuration command to announce its candidacy as a BSR:
Router(config)# ip pim bsr-candidate <ifname> <has-mask-length> <priority>
• Ifname—Router interface from which the bootstrap router address is derived to indicate its candidacy.
• Hash-mask-length— Length of a mask (32-bit maximum) that is to be masked with the group address before
the hash function is called.