Release Notes for Cisco Catalyst Blade Switch 3120 for HP, Cisco IOS Release 12.2(46)SE

OL-16968-01

Limitations and Restrictions

• When you configure the IGMP snooping throttle limit by using the ip igmp max-groups number

interface configuration on a port-channel interface, the groups learned on the port-channel might

exceed the configured throttle limit number when all of these conditions are true:

–

The port-channel is configured with member ports across different switches in the stack.

–

One of the member switches reloads.

–

The member switch that is reloading has a high rate of IP IGMP joins arriving on the

port-channel member port.

The workaround is to disable the IGMP snooping throttle limit by using the no ip igmp max-groups

number interface configuration command and then to reconfigure the same limit again.

(CSCse39909)

QoS

These are the quality of service (QoS) limitations:

• When QoS is enabled and the egress port receives pause frames at the line rate, the port cannot send

packets.

There is no workaround. (CSCeh18677)

• Egress shaped round robin (SRR) sharing weights do not work properly with system jumbo MTU

frames.

There is no workaround. (CSCsc63334)

• In a hierarchical policy map, if the VLAN-level policy map is attached to a VLAN interface and the

name of the interface-level policy map is the same as that for another VLAN-level policy map, the

switch rejects the configuration, and the VLAN-level policy map is removed from the interface.

The workaround is to use a different name for the interface-level policy map. (CSCsd84001)

• If the ingress queue has low buffer settings and the switch sends multiple data streams of system

jumbo MTU frames at the same time at the line rate, the frames are dropped at the ingress.

There is no workaround. (CSCsd72001)

• When you use the srr-queue bandwidth limit interface configuration command to limit port

bandwidth, packets that are less than 256 bytes can cause inaccurate port bandwidth readings. The

accuracy is improved when the packet size is greater than 512 bytes. There is no workaround.

(CSCsg79627)

Routing

These are the routing limitations:

• The switch stack might reload if the switch runs with this configuration for several hours, depleting

the switch memory and causing the switch to fail:

–

The switch has 400 Open Shortest Path First (OSPF) neighbors.

–

The switch has thousands of OSPF routes.

The workaround is to reduce the number of OSPF neighbors to 200 or less. (CSCse65252)

• When the PBR is enabled and QoS is enabled with DSCP settings, the CPU utilization might be high

if traffic is sent to unknown destinations.

The workaround is to not send traffic to unknown destinations. (CSCse97660)