Changing The Interval For Pim-Sm Neighbor Notification - HP ProCurve 6200yl Multicast And Routing Manual

PIM-SM (Sparse Mode)
Configuring PIM-SM on the Router
4-30

Changing the Interval for PIM-SM Neighbor Notification

Syntax: ip pim-sparse hello-interval < 5 - 300 >
vlan < vid > ip pim-sparse hello-interval < 5 - 300 >
Changes the frequency at which the router transmits PIM
"Hello" messages on the current VLAN. The router uses
"Hello" packets to inform neighboring routers of its presence.
The router also uses this setting to compute the Hello Hold
Time, which is included in Hello packets sent to neighbor
routers. Hello Hold Time tells neighbor routers how long to
wait for the next Hello packet from the router. If another
packet does not arrive within that time, the router removes
the neighbor adjacency on that VLAN from the routing table,
which removes any flows running on that interface.
Shortening the Hello interval reduces the Hello Hold Time.
This changes how quickly other routers will stop sending
traffic to the router if they do not receive a new Hello packet
when expected. For example, if multiple routers are
connected to the same VLAN and the router requests
multicast traffic, all routers on the VLAN receive that traffic.
(Those which have pruned the traffic will drop it when they
receive it.) If the upstream router loses contact with the
router receiving the multicast traffic (that is, fails to receive
a Hello packet when expected), then the shorter Hello Interval
causes it to stop transmitting multicast traffic onto the
VLAN sooner, resulting in less unnecessary bandwidth use.
(Default: 30 seconds.)