Installation guide

11
Release Notes for the Cisco ME 3400 Ethernet Access Switch, Cisco IOS Release 12.2(44)SE
OL-14632-01
Limitations and Restrictions
• If an IGMP report packet has two multicast group records, the switch removes or adds interfaces
depending on the order of the records in the packet:
– If the ALLOW_NEW_SOURCE record is before the BLOCK_OLD_SOURCE record, the
switch removes the port from the group.
– If the BLOCK_OLD_SOURCE record is before the ALLOW_NEW_SOURCE record, the
switch adds the port to the group.
There is no workaround. (CSCec20128)
• When IGMP snooping is disabled and you enter the switchport block multicast interface
configuration command, IP multicast traffic is not blocked.
The switchport block multicast interface configuration command is only applicable to non-IP
multicast traffic.
There is no workaround. (CSCee16865)
• Incomplete multicast traffic can be seen under either of these conditions:
– You disable IP multicast routing or re-enable it globally on an interface.
– A switch mroute table temporarily runs out of resources and recovers later.
The workaround is to enter the clear ip mroute privileged EXEC command on the interface.
(CSCef42436)
Routing
These are the routing limitations:
• The switch does not support tunnel interfaces for routed traffic.
• A route map that has an ACL with a Differentiated Services Code Point (DSCP) clause cannot be
applied to a Layer 3 interface. The switch rejects this configuration and displays a message that the
route map is unsupported. There is no workaround. (CSCea52915)
• A spanning-tree loop might occur if all of these conditions are true:
– Port security is enabled with the violation mode set to protected.
– The maximum number of secure addresses is less than the number of switches connected to the
port.
– There is a physical loop in the network through a switch whose MAC address has not been
secured, and its BPDUs cause a secure violation.
The workaround is to change any one of the listed conditions. (CSCed53633)
QoS
These are the quality of service (QoS) limitations:
• When you use the bandwidth policy-map class command to configure more than one class in a
policy map for Class-based Weighted Fair Queuing (CBWFQ), and the committed information rate
(CIR) bandwidth for any of the classes is less than 2 percent of the interface rate, the CBWFQ
classes in the policy may not receive the configured CIR bandwidths.
There is no workaround, but it is unlikely that a CBWFQ class would be configured with such a low
CIR bandwidth. (CSCsb98219)