US Patent 7738385 Mirroring of data in a network device

A network device for processing packets includes an ingress module for performing switching functions on an incoming packet, a memory management unit for storing packets and performing resource checks on each packet and an egress module for performing packet modification and transmitting a modified packet to an appropriate egress port. The egress module is configured to send an unmodified version of the incoming packet to an ingress mirrored-to-port when an ingress port, upon which the incoming packet is received, is configured to mirror packets received by the ingress port.