Configuration Guidelines And Limitations - Cisco WS-C2955T-12 Software Manual

Chapter 6 Configuring the System

Configuration Guidelines and Limitations

Follow these guidelines when configuring MVR:
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MVR implementation has these limitations:
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All receiver ports on a switch must belong to the same VLAN and must not be trunk ports.
In applications where the receiver ports represent subscribers to a service, we recommend
configuring receiver ports as follows:
Enable protected port on all receiver ports to isolate the ports from one another.
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Enable port blocking on all receiver ports to prevent unknown unicast and multicast packets.
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Before configuring MVR groups, configure all MVR parameters, including the multicast VLAN. If
you want to change the MVR parameters after MVR groups have been configured, follow these
steps:
Enter the no mvr command to disable MVR.
a.
Enter the mvr vlan <vlan-id> command to change the multicast VLAN.
b.
The maximum number of mvr entries is determined by the switch hardware. Each MVR group
c.
represents a TV channel.
Enter the mvr command to enable MVR. You do not need to reconfigure the MVR groups. The
d.
switch uses the MVR groups when you re-enable MVR.
Each channel is one multicast stream destined for a unique IP multicast address.
Make sure the router is statically configured to forward multicast traffic for the MVR groups to the
switch. The router should not depend on IGMP join requests from hosts (forwarded by the switch)
to forward multicast traffic to the switch.
The receiver VLAN is the VLAN to which the first configured receiver port belongs. If the first
receiver port is a dynamic port with an unassigned VLAN, it becomes an inactive receiver port and
does not take part in MVR unless it is assigned to the receiver VLAN. The receiver VLAN is reset
whenever there are no remaining receiver ports on the switch (active or inactive), which means that
the receiver VLAN might change every time the first receiver port is configured.
MVR is supported on all Catalyst 3500 XL switches and on only the modular Catalyst 2900 XL
switches.
Unknown multicast packets, unknown unicast packets, and broadcast packets are leaked from the
multicast VLAN to the receiver ports.
MVR does not support IP-address aliasing and therefore requires that each IP multicast address
maps to only one Layer 2 MAC address. In MVR, you cannot configure multiple IP addresses that
map to the same MAC address.
The same multicast MAC addresses cannot belong to both CGMP and MVR groups. CGMP does
not dynamically learn addresses that are MVR group members. If you want CGMP to learn an
address that is already an MVR group member, remove the address from the MVR group.
Conversely, you cannot add an address to an MVR group if it is already a CGMP group member. If
you want an address that is already a CGMP group member to be an MVR group member, remove
the address from the CGMP group, and then statically add it to the MVR group. For information
about CGMP, see the "Configuring CGMP" section on page
Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
Configuring MVR
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