Configuring A Hello Message Filter; Configuring Pim Hello Options - H3C LS-3100-52P-OVS-H3 Operation Manual

Generally, 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 more and
more 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.
Follow these steps to configure a hello message filter:
To do...
Enter system view
Enter interface view
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

No matter in a PIM-DM domain or a PIM-SM domain, the hello messages sent among routers contain
many configurable options, including:
DR_Priority (for PIM-SM only): priority for DR election. The device 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 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
Use the command...
system-view
interface interface-type
interface-number
pim neighbor-policy
acl-number
1-31
Remarks
—
—
Required
No hello message filter by default.