Configuring A Hello Message Filter; Configuring Pim Hello Options - HP A6600 Configuration Manual

To do...
3. Configure a multicast group
filter.
A smaller distance from the filter to the multicast source results in a more remarkable filtering effect.
This filter works not only on independent multicast data but also on multicast data encapsulated in register
messages.

Configuring a hello message filter

Along with the wide applications of PIM, the security requirement for the protocol is becoming
increasingly demanding. The establishment of correct PIM neighboring relationships is the prerequisite for
secure application of PIM. You can configure a legal source address range for hello messages on
interfaces of routers to ensure the correct PIM neighboring relationships, and thus to guard against PIM
message attacks.
To do...
1. Enter system view.
2. Enter interface view.
3. Configure a hello message
filter.
With the hello message filter configured, if hello messages of an existing PIM neighbor fail to pass the
filter, the PIM neighbor will be removed automatically when it times out.

Configuring PIM hello options

In both a PIM-DM domain and a PIM-SM domain, the hello messages sent among routers contain the
following configurable options:
DR_Priority (for PIM-SM only)—Priority for DR election. The router with the highest priority wins the
•
DR election. You can configure this parameter on all the routers in a multi-access network directly
connected to multicast sources or receivers.
Holdtime—The timeout time of PIM neighbor reachability state. When this timer times out, if the
•
router has received no hello message from a neighbor, it assumes that this neighbor has expired or
become unreachable.
• LAN_Prune_Delay—The delay of prune messages on a multi-access network. This option consists of
LAN-delay (namely, prune message delay), override-interval, and neighbor tracking flag. If the
LAN-delay or override-interval values of different PIM routers on a multi-access subnet are different,
the largest value will take effect. If you want to enable neighbor tracking, be sure to enable the
neighbor tracking feature on all PIM routers on a multi-access subnet.
The LAN-delay setting will cause the upstream routers to delay processing received prune messages. The
override-interval sets the length of time that a downstream router can 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
LAN-delay plus override-interval. If the downstream router needs to continue receiving multicast data, it
must send a join message within the prune override interval. Otherwise, the upstream router will perform
the prune action when the period of LAN-delay plus override-interval times out.
Use the command...
source-policy acl-number
Use the command...
system-view
interface interface-type
interface-number
pim neighbor-policy acl-number
131
Remarks
Required.
No multicast data filter by default.
Remarks
—
—
Required.
No hello message filter by default.