Lucent Technologies 6000 - Manual (Page 429)

Setting Up IP Multicast Forwarding
Configuring multicast forwarding
MAX 6000/3000 Network Configuration Guide 10-3
Specifying the rate which multicast clients accept packets
The Rate Limit parameter specifies the rate at which the MAX accepts multicast packets from
its clients. For a particular WAN connection, you can set the Multicast Rate parameter in the
Connection profile. The rate limit does not affect the MBONE interface. The default setting is
100, which disables multicast forwarding on the interface. The forwarder handles IGMP
packets, but does not accept packets from clients or forward multicast packets from the
MBONE router.
To begin forwarding multicast traffic on the interface, you must set the Rate Limit parameter to
a number less than 100. For example, if you set it to 5, the MAX accepts a packet from
multicast clients on the interface once every five seconds. The MAX discards any subsequent
packets received in that five-second window.
Because multiple multicast clients can have multiple active sessions for identical IGMP groups
via a single WAN interface on the MAX, you can configure the MAX to query each WAN
interface from which it receives a leave group message, to make sure there are no clients
with active multicast sessions for the same group on that interface.
Querying for active group members
When the MAX receives a leave group message for a WAN interface for which you
configure a value for Grp Leave Delay, it sends a query to the WAN interface, requesting that
any active members of the group respond. If the MAX receives a response within the time
period you specify in the Grp Leave Delay parameter, it does not forward the leave group
message to the MBONE. Otherwise, it sends a leave group message to the MBONE, and it
clears the IGMP group session from its tables.
Multicast interfaces
The MAX creates the following multicast interfaces at system startup:
Interface Specified destination address
mcast 224.0.0.0/4. All multicast addresses, except for special addresses discussed in
this section, are directed to this interface.
local 224.0.0.1/32. Multicast address for all systems on the local subnet. The MAX
does not forward packets sent to this address.
local 224.0.0.2/32. Multicast address for all routers on the local subnet. The MAX
does not forward packets sent to this address.
local 224.0.0.5/32. Multicast address for all OSPF routers on the network. The MAX
does not forward packets sent to this address.
If you disable OSPF routing, this route changes from local to a black-hole
interface.
local 224.0.0.6/32. Multicast address for all OSPF Designated Routers on the net-
work. The MAX does not forward packets sent to this address.
If you disable OSPF routing, this route changes from local to a black-hole
interface.