Cisco Cisco Fiber IGESM Switch Module for IBM Notas de publicación

When the Internet Group Management Protocol (IGMP) Immediate Leave is configured, new ports 
are added to the group membership each time a join message is received, and ports are pruned 
(removed) each time a leave message is received. 

If the join and leave messages arrive at high rate, the CPU can become busy processing these 
messages. For example, the CPU usage is approximately 50 percent when 50 pairs of join and leave 
messages are received each second. Depending on the rate at which join and leave messages are 
received, the CPU usage can go very high, even up to 100 percent, as the switch continues processing 
these messages.

The workaround is to only use the Immediate Leave processing feature on VLANs where a single 
host is connected to each port. (CSCdx95638)

In a Remote Switched Port Analyzer (RSPAN) session, if at least one switch is used as an 
intermediate or destination switch and if traffic for a port is monitored in both directions, traffic does 
not reach the destination switch. 

These are the workarounds:

Use a Catalyst 3550 or Catalyst 6000 switch as an intermediate or destination switch. 

Monitor traffic in only one direction if a switch module is used as an intermediate or destination 
switch. (CSCdy38476)

If you assign a nonexistent VLAN ID to a static-access EtherChannel by setting the 
ciscoVlanMembershipMIB:vmVlan object, the switch does not create the VLAN in the VLAN 
database. (CSCdy65850)

When you configure a dynamic switch port by using the switchport access vlan dynamic interface 
configuration command, the port might allow unauthorized users to access network resources if the 
interface changes from access mode to trunk mode through Dynamic Trunking Protocol (DTP) 
negotiation.

The workaround is to configure the port as a static access port. (CSCdz32556)

The output from the show stack privileged EXEC command might show a large number of false 
interrupts.

There is no workaround. The number of interrupts does not affect the switch functionality. 
(CSCdz34545)

If you configure a static secure MAC address on an interface before enabling port security on the 
interface, the same MAC address is allowed on multiple interfaces. If the same MAC address is 
added on multiple ports before enabling port security and port security is later enabled on those 
ports, only the first MAC address can be added to the hardware database. If port security is first 
enabled on the interface, the same static MAC address is not allowed on multiple interfaces. 
(CSCdz74685)

If you press and hold the spacebar while the output of any show user EXEC command is being 
displayed, the Telnet session stops, and you can no longer communicate with the management 
VLAN.

These are the workarounds:

Enter the show commands from privileged EXEC mode, and use this command to set the 
terminal length to zero:

switch# terminal length 0

 

Open a Telnet session directly from a PC or workstation to the switch.

Do not hold down the spacebar while scrolling through the output of a show user EXEC 
command. Instead, slowly press and release the spacebar. (CSCea12888)