System and method for filtering packets in a switching environment

A system for filtering packets in a switching environment, comprising:

• an input port of a switch configured to receive a packet, the input port associated with an input port module;
• a memory of the switch configured to store at least a portion of the packet, the memory logically divided into a plurality of blocks;
• a routing module of the switch configured to determine one or more output ports of the switch from which the packet is to be communicated from the switch, the input port module configured to determine whether the packet is an illegal packet after the routing module begins to determine the one or more output ports from which the packet is to be communicated from the switch;
• a central agent of the switch comprising a drop queue and configured to drop at least some of the packet from the memory if the packet is an illegal packet;
• and
• one or more output ports of the switch configured to communicate the packet from the switch if the packet is a legal packet and if the one or more output ports are determined by the routing module;
• wherein the central agent is further configured to allocate at least a first block and a second block of memory to the input port to store the packet, and wherein, if the packet is an illegal packet:
• the routing module is further configured to send a drop request for the first block to the drop queue;
• and
• the input port module is further configured to reuse the second block for storage of another packet without a drop request for the second block being sent to the drop queue and without waiting for the second block to be released to a pool of available blocks.