Changing maximum time before the routing switch transmits the initial PIM
hello message on the VLAN
Syntax:
ip pim-dense [hello-delay 0-5]
vlan [
vid
]ip pim-dense [hello-delay 0-5]
Changes the maximum time in seconds before the routing switch actually transmits the initial PIM hello message
on the current VLAN. In cases where a new VLAN activates with connections to multiple routers, if all of the
connected routers sent hello packets at the same time, the receiving router could become momentarily
overloaded. This value randomizes the transmission delay to a time between 0 and the hello delay setting. Using
0 means no delay.
After the routing switch sends the initial hello packet to a newly detected VLAN interface, it sends subsequent
hello packets according to the current hello interval setting.
NOTE:
Not used with the
[no]
form of the
ip pim-dense
command.
Default: 5 seconds
Changing the interval the routing switch waits for the graft ack from
another router before resending the graft request
Syntax:
ip pim-dense [graft-retry-interval[1-10]]
vlan[
vid
]ip pim-dense [graft-retry-interval[1-10]]
Graft packets result when a downstream router transmits a request to join a flow. The upstream router responds
with a graft acknowledgment packet. If the graft ack (acknowledgement) is not received within the time period of
the graft-retry-interval, it resends the graft packet. The command
[graft-retry-interval[1-10]]
changes
the interval (in seconds) the routing switch waits for the graft ack from another router before resending the graft
request.
NOTE:
Not used with the
[no]
form of the
ip pim-dense
command.
Default: 3 seconds
Changing the number of times the routing switch retries sending the same
graft packet to join a flow
Syntax:
ip pim-dense [max-graft-retries[1-10]]
vlan[
vid
]ip pim-dense [max-graft-retries[1-10]]
Changes to the number of times the routing switch will retry sending the same graft packet to join a flow. If a graft
ack response is not received after the specified number of retries, the routing switch ceases trying to join the flow.
In this case the flow is removed until either a state-refresh from upstream re-initiates the flow or an upstream
router floods the flow.
Increasing this value helps to improve multicast reliability.
Chapter 3 PIM-DM (Dense Mode)
57
