3Com MSR 50 Series Configuration Manual page 1260

1260 C 74: IP 6 PIM C
HAPTER V ONFIGURATION
The override-interval sets the length of time a downstream router is allowed to
wait before sending a prune override message. When a router receives a prune
message from a downstream router, it does not perform the prune action
immediately; instead, it maintains the current forwarding state for a period of time
defined by LAN-delay. If the downstream router needs to continue receiving IPv6
multicast data, it must send a prune override message within the prune override
interval; otherwise, the upstream route will perform the prune action when the
LAN-delay timer times out.
A hello message sent from an IPv6 PIM router contains a generation ID option. The
generation ID is a random value for the interface on which the hello message is
sent. Normally, the generation ID of an IPv6 PIM router does not change unless the
status of the router changes (for example, when IPv6 PIM is just enabled on the
interface or the device is restarted). When the router starts or restarts sending
hello messages, it generates a new generation ID. If an IPv6 PIM router finds that
the generation ID in a hello message from the upstream router has changed, it
assumes that the status of the upstream neighbor is lost or the upstream neighbor
has changed. In this case, it triggers a join message for state update.
If you disable join suppression (namely, enable neighbor tracking), the upstream
router will explicitly track which downstream routers are joined to it. The join
suppression feature should be enabled or disabled on all IPv6 PIM routers on the
same subnet.
Configuring hello options globally
Follow these steps to configure hello options globally:
To do...
Enter system view
Enter IPv6 PIM view
Configure the priority for DR
election
Configure IPv6 PIM neighbor
timeout time
Configure the prune delay
time (LAN-delay)
Configure the prune override
interval
Disable join suppression
Configuring hello options on an interface
Follow these steps to configure hello options on an interface:
To do...
Enter system view
Enter interface view
Use the command...
system-view
pim ipv6
hello-option dr-priority
priority
hello-option holdtime
interval
hello-option lan-delay
interval
hello-option
override-interval interval
hello-option
neighbor-tracking
Use the command...
system-view
interface interface-type
interface-number
Remarks
-
-
Optional
1 by default
Optional
105 seconds by default
Optional
500 milliseconds by default
Optional
2,500 milliseconds by default
Optional
Enabled by default
Remarks
-
-