Cisco Catalyst 2960 Series, Configuration Manual

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The actual leave latency in the network is usually the configured leave time. However, the leave time
might vary around the configured time, depending on real-time CPU load conditions, network delays
and the amount of traffic sent through the interface.
• The IGMP throttling action restriction can be applied only to Layer 2 ports. You can use
ip igmp
max-groups action replace interface configuration command on a logical EtherChannel interface but
cannot use it on ports that belong to an EtherChannel port group.
When the maximum group limitation is set to the default (no maximum), entering the ip igmp max-groups
action
{
deny
|
replace
} command has no effect.
If you configure the throttling action and set the maximum group limitation after an interface has added
multicast entries to the forwarding table, the forwarding-table entries are either aged out or removed,
depending on the throttling action.
Related Topics
IGMP Versions, on page 119
Configuring IGMP Profiles , on page 151
Applying IGMP Profiles , on page 154
Setting the Maximum Number of IGMP Groups , on page 155
Configuring the IGMP Throttling Action , on page 157
IGMP Filtering and Throttling, on page 126
Restrictions for MVR
The following are restrictions for MVR:
• Only Layer 2 ports participate in MVR. You must configure ports as MVR receiver ports.
• Only one MVR multicast VLAN per switch or switch stack is supported.
• Receiver ports can only be access ports; they cannot be trunk ports. Receiver ports on a switch can be
in different VLANs, but should not belong to the multicast VLAN.
• The maximum number of multicast entries (MVR group addresses) that can be configured on a switch
(that is, the maximum number of television channels that can be received) is 256.
• MVR multicast data received in the source VLAN and leaving from receiver ports has its time-to-live
(TTL) decremented by 1 in the switch.
• Because MVR on the switch uses IP multicast addresses instead of MAC multicast addresses, alias IP
multicast addresses are allowed on the switch. However, if the switch is interoperating with Catalyst
3550 or Catalyst 3500 XL switches, you should not configure IP addresses that alias between themselves
or with the reserved IP multicast addresses (in the range 224.0.0.xxx).
• Do not configure MVR on private VLAN ports.
• MVR is not supported when multicast routing is enabled on a switch. If you enable multicast routing
and a multicast routing protocol while MVR is enabled, MVR is disabled, and you receive a warning
message. If you try to enable MVR while multicast routing and a multicast routing protocol are enabled,
the operation to enable MVR is cancelled, and you receive an error message
• MVR data received on an MVR receiver port is not forwarded to MVR source ports.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
117
Restrictions for Configuring IGMP Snooping and MVR