Port Mirror and Packet Capture Operation

The current version of CPSW within NetCP does not support port mirroring feature. The PA LLD and the PASS firmware have been enhnaced to support EMAC port mirroring operation OR EMAC port packet capture feature.

When Port Mirror configuration is enabled, some of the ethernet ports can be configured as mirror ports. Mirror port receives and transmits ethernet traffic as normal and other non-mirror ports can be configured to have its traffic mirrored to any mirror port. A port that has its traffic mirrored means that all traffic to and/or from this port can also be transmitted (mirrored) to its mirror port. PA supports individual ingress and egress control of the EMAC port to be mirrored. The mirror port itself can never be mirrored. It is the responsibility of the higher level software to take care of this condition to avoid recursion and undesired effects. Packets are mirrored excatly as they are received/transmitted. No additional mac header or equivalent is placed on these packets.

In addition, PASS also supports the packet capture feature which is valid only if port mirroring is not in use and if it is enabled on an interface. The feature works in a similar fashion to port mirroring except that the captured packet will be copied and sent to a configured hardware queue instead of the mirror port.

The host software should enable and configure either the port mirror or packet capture operation on that interface using Pa_control API. And global system configuration is required to enable those features system wide.

Note:
The design assumes that the port mirroring feature is not required when the device is operating with the CPSW switch active (i.e., ALE bypass disabled) or in a NETCP bridge or s/w bridge mode.

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