Unified exception handling may be provided by processing a data packet
through at least two pipelined processing stages in a data packet
processor such as a switch, router, bridge, or similar network device,
each of the data packets having associated with it (while it is being
processed) an exception map disposed in a memory of the network device.
The bits in the exception map are set, modified, or reset in response to
exception conditions detected at the various processing stages. After the
packet has been fully processed, an exception handler takes as an input
the exception map and further processes the packet in response to the
state of the exception map.