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Catalyst 3750 Metro Switch Command Reference
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Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
mvr (global configuration)
No IP multicast addresses are configured on the switch by default.
The default group ip address count is 0.
The default query response time is 5 tenths (one-half) second.
The default multicast VLAN for MVR is VLAN 1.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the
mvr group
command to statically set all the IP multicast addresses to take part in MVR. Any
multicast data sent to a configured multicast address is sent to all the source ports on the switch and to
all receiver ports that have registered to receive data on that IP multicast address.
When MVR mode is compatible (the default), you can configure 512 multicast entries (MVR group
addresses). Although the range appears in the command line help as 1 to 2000, the switch allows only
512 groups.
When MVR mode is dynamic, you can configure a maximum of 2000 MVR group addresses on the
switch. The maximum number of simultaneous active multicast streams (that is, the maximum number
of television channels that can be receiving) is 512. When this limit is reached, a message is generated
that the
Maximum hardware limit of groups had been reached
. Note that a hardware entry occurs when
there is an IGMP join on a port or when you configure a port to join a group by entering the
mvr vlan
vlan-id
group
ip-address
interface configuration command.
MVR supports aliased IP multicast addresses on the switch. However, if the switch is interacting with
Catalyst 3550 or 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).
The
mvr querytime
command applies only to receiver ports.
If the switch MVR is interacting with Catalyst 2900 XL or 3500 XL switches, set the multicast mode to
compatible.
When operating in compatible mode, MVR does not support IGMP dynamic joins on MVR source ports.
MVR can coexist with IGMP snooping on a switch.
Multicast routing and MVR cannot coexist
on a switch. If you enable multicast routing and a multicast
routing protocol while MVR is enabled, MVR is disabled, and a warning message appears. If you try to
enable MVR while multicast routing and a multicast routing protocol are enabled, the operation to
enable MVR is cancelled and an error message appears.
Starting with Cisco IOS release 12.2(52)SE, you can enter the
mvr ringmode flood
global configuration
command to ensure that data forwarding in a ring topology is limited to membership detected ports and
excludes forwarding to multicast router ports. This prevents unicast traffic from being dropped in a ring
environment when MVR multicast traffic is flowing in one direction and unicast traffic is flowing in the
other direction.
Release
Modification
12.1(14)AX
This command was introduced.
12.2(52)SE
The ringmode flood keywords were added.
