Alcatel-Lucent 7750 SR Manual page 715

ingress
Syntax ingress
Context config>service>vpls>mesh-sdp
config>service>vpls>spoke-sdp
Description This command configures the ingress SDP context.
mfib-allowed-mda-destinations
Syntax mfib-allowed-mda-destinations
Context config>service>vpls>mesh-sdp>egress
config>service>vpls>spoke-sdp>egress
Description
This command enables the context to configure MFIB-allowed MDA destinations.
The allowed-mda-destinations node and the corresponding mda command are used on spoke and
mesh SDP bindings to provide a list of MDA destinations in the chassis that are allowed as
destinations for multicast streams represented by [*,g] and [s,g] multicast flooding records on the
VPLS service. The MDA list only applies to IP multicast forwarding when IGMP snooping is enabled
on the VPLS service. The MDA list has no effect on normal VPLS flooding such as broadcast, L2
multicast, unknown destinations or non-snooped IP multicast.
At the IGMP snooping level, a spoke or mesh SDP binding is included in the flooding domain for an
IP multicast stream when it has either been defined as a multicast router port, received a IGMP query
through the binding or has been associated with the multicast stream through an IGMP request by a
host over the binding. Due to the dynamic nature of the way that a spoke or mesh SDP binding is
associated with one or more egress network IP interfaces, the system treats the binding as appearing
on all network ports. This causes all possible network destinations in the switch fabric to be included
in the multicast streams flooding domain. The MDA destination list provides a simple mechanism
that narrows the IP multicast switch fabric destinations for the spoke or mesh SDP binding.
If no MDAs are defined within the allowed-mda-destinations node, the system operates normally and
will forward IP multicast flooded packets associated with the spoke or mesh SDP binding to all
switch fabric taps containing network IP interfaces.
The MDA inclusion list should include all MDAs that the SDP binding may attempt to forward
through. A simple way to ensure that an MDA that is not included in the list is not being used by the
binding is to define the SDP the binding is associated with as MPLS and use an RSVP-TE LSP with a
strict egress hop. The MDA associated with the IP interface defined as the strict egress hop should be
present in the inclusion list. If the inclusion list does not currently contain the MDA that the binding is
forwarding through, the multicast packets will not reach the destination represented by the binding.
By default, the MDA inclusion list is empty.
If an MDA is removed from the list, the MDA is automatically removed from the flooding domain of
any snooped IP multicast streams associated with a destination on the MDA unless the MDA was the
last MDA on the inclusion list. Once the inclusion list is empty, all MDAs are eligible for snooped IP
multicast flooding for streams associated with the SDP binding.
7750 SR OS Services Guide
Virtual Private LAN Services
Page 715