Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Implementing IPv6 Multicast
Information About Implementing IPv6 Multicast
IPv6 Multicast User Authentication and Profile Support
IPv6 multicast by design allows any host in the network to become a receiver or a source for a multicast
group. Therefore, multicast access control is needed to control multicast traffic in the network. Access
control functionality consists mainly of source access control and accounting, receiver access control
and accounting, and provisioning of this access control mechanism.
Multicast access control provides an interface between multicast and authentication, authorization, and
accounting (AAA) for provisioning, authorizing, and accounting at the last-hop switch, receiver access
control functions in multicast, and group or channel disabling capability in multicast.
When you deploy a new multicast service environment, it is necessary to add user authentication and
provide a user profile download on a per-interface basis. The use of AAA and IPv6 multicast supports
user authentication and downloading of the user profile in a multicast environment.
The event that triggers the download of a multicast access-control profile from the RADIUS server to
the access switch is arrival of an MLD join on the access switch. When this event occurs, a user can cause
the authorization cache to time out and request download periodically or use an appropriate multicast
clear command to trigger a new download in case of profile changes.
Accounting occurs via RADIUS accounting. Start and stop accounting records are sent to the RADIUS
server from the access switch. In order for you to track resource consumption on a per-stream basis, these
accounting records provide information about the multicast source and group. The start record is sent
when the last-hop switch receives a new MLD report, and the stop record is sent upon MLD leave or if
the group or channel is deleted for any reason.
IPv6 MLD Proxy
The MLD proxy feature provides a mechanism for a switch to generate MLD membership reports for all
(*, G)/(S, G) entries or a user-defined subset of these entries on the switch's upstream interface. The
MLD proxy feature enables a device to learn proxy group membership information, and forward
multicast packets based upon that information.
If a switch is acting as RP for mroute proxy entries, MLD membership reports for these entries can be
generated on user specified proxy interface.
Protocol Independent Multicast
Protocol Independent Multicast (PIM) is used between switches so that they can track which multicast
packets to forward to each other and to their directly connected LANs. PIM works independently of the
unicast routing protocol to perform send or receive multicast route updates like other protocols.
Regardless of which unicast routing protocols are being used in the LAN to populate the unicast routing
table, Cisco IOS PIM uses the existing unicast table content to perform the Reverse Path Forwarding
(RPF) check instead of building and maintaining its own separate routing table.
You can configure IPv6 multicast to use either PIM-SM or PIM-SSM operation, or you can use both
PIM-SM and PIM-SSM together in your network.
PIM-Sparse Mode
IPv6 multicast provides support for intradomain multicast routing using PIM-SM. PIM-SM uses unicast
routing to provide reverse-path information for multicast tree building, but it is not dependent on any
particular unicast routing protocol.