Release Notes for Cisco Catalyst Blade Switch 3120 for HP, Cisco IOS Release 12.2(52)SE

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OL-19714-01

Limitations and Restrictions

Multicasting

• Multicast packets with a time-to-live (TTL) value of 0 or 1 are flooded in the incoming VLAN when

all of these conditions are met:

–

Multicast routing is enabled in the VLAN.

–

The source IP address of the packet belongs to the directly connected network.

–

The TTL value is either 0 or 1.

The workaround is to not generate multicast packets with a TTL value of 0 or 1, or disable multicast

routing in the VLAN. (CSCeh21660)

• Multicast packets denied by the multicast boundary access list are flooded in the incoming VLAN

when all of these conditions are met:

–

Multicast routing is enabled in the VLAN.

–

The source IP address of the multicast packet belongs to a directly connected network.

–

The packet is denied by the IP multicast boundary access-list configured on the VLAN.

There is no workaround. (CSCei08359)

• Reverse path forwarding (RPF) failed multicast traffic might cause a flood of Protocol Independent

Multicast (PIM) messages in the VLAN when a packet source IP address is not reachable.

The workaround is to not send RPF-failed multicast traffic, or make sure that the source IP address

of the RPF-failed packet is reachable. (CSCsd28944)

• If the clear ip mroute privileged EXEC command is used when multicast packets are present, it

might cause temporary flooding of incoming multicast traffic in the VLAN.

There is no workaround. (CSCsd45753)

• When you configure the ip igmp max-groups number and ip igmp max-groups action replace

interface configuration commands and the number of reports exceed the configured max-groups

value, the number of groups might temporarily exceed the configured max-groups value. No

workaround is necessary because the problem corrects itself when the rate or number of IGMP

reports are reduced. (CSCse27757)

• 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)

Quality of Service (QoS)

• 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)