Global switching mode is Truncated dCEF mode is not enforced for system to operate Fabric module is not required for system to operate Modules are allowed to operate in bus mode Truncated mode is allowed, due to presence of CEF720 module
Module Slot Switching Mode 1 Crossbar 3 Crossbar 4 Crossbar 5 Bus 6 Crossbar 7 Crossbar 8 Crossbar 9 Bus
Basically, with Bus mode, all linecards see all packets, and only accept the ones that they need or are destined for them, whereas in Crossbar mode, packets are sent directly to the specific linecard.
Solution for Reason 1 —Remove the monitor session reserved for service modules. In order to do this, issue the no monitor session servicemodule command, and then try to reinitialize the operation. This disables the internal-span required by the FWSM to process multicast traffic, which frees the resources on the SPAN-ASIC in order to allow DEC to work.
Solution for Reason 2 —The workaround is to change the mode of the modules to bus mode. In order to force fabric-enabled modules into bus switching mode, use the fabric switching-mode force bus-mode command.
In order to resolve the issue mentioned in this bug, you can upgrade to Cisco IOS Software Release 12.2(18)SXF7 or later, which can be downloaded from Cisco Downloads.