Patent ID: 7440467

Claim:
A method of operating a packet switch connected to a packet-switching network, wherein the packet switch includes a plurality of ports and a plurality of filters, wherein a first port is configured as a network port connected to the packet-switching network, the method comprising: configuring a second port on the packet switch to operate as a first instrument port connected to a network instrument; establishing a logical connection between the network port and the first instrument port; forwarding packets received from the packet-switching network through the network port to the first instrument port; after the packets are forwarded from the network port, filtering the packets using one of the filters before sending the packets out the first instrument port; configuring a third port on the packet switch to operate as a first loop-back port, wherein a packet sent out the first loop-back port is looped back in through the first loop-back port, wherein establishing a logical connection between the network port and the first instrument port includes: establishing a logical connection from the network port to the first loop-back port; and establishing a logical connection from the first loop-back port to the first instrument port, and wherein forwarding packets received from the packet-switching network includes: forwarded the received packets from the network port to the first loop-back port; and forwarding the received packets from the first loop-back port to the first instrument port; and establishing a first filtering criterion for a first filter associated with the first loop-back port, wherein filtering the packets includes: filtering the packets using the first filter associated with the first loop-back port based on the first established filtering criterion before forwarding the received packets from the first loop-back port to the first instrument port.