Cisco Cisco IOS Software Release 12.2(58)SE

For example, with load balance configured as dst-ip with 150 distinct incrementing destination IP 
addresses, and the number of ports in the EtherChannel set to either 2, 4, or 8, load distribution is 
optimal.(CSCeh81991)

When the rate of received DHCP requests

exceeds 2,000 packets per minute for a long time, the 

response time might be slow when you are using the console. 

The workaround is to use rate limiting on DHCP traffic to prevent a denial of service attack from 
occurring. (CSCeb59166)

If the number of multicast routes and Internet Group Management Protocol (IGMP) groups are more 
than the maximum number specified by the show sdm prefer global configuration command, the 
traffic received on unknown groups is flooded in the received VLAN even though the show ip igmp 
snooping multicast-table privileged EXEC command output shows otherwise. 

The workaround is to reduce the number of multicast routes and IGMP snooping groups to less than 
the maximum supported value. (CSCdy09008)

IGMP filtering is applied to packets that are forwarded through hardware. It is not applied to packets 
that are forwarded through software. Hence, with multicast routing enabled, the first few packets are 
sent from a port even when IGMP filtering is set to deny those groups on that port. 

There is no workaround. (CSCdy82818)

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)

After you configure a switch to join a multicast group by entering the ip igmp join-group 
group-address interface configuration command, the switch does not receive join packets from the 
client, and the switch port connected to the client is removed from the IGMP snooping forwarding 
table. 

Use one of these workarounds: