184.108.40.206. Packet Discard
There are a few conditions where packets are discarded and errors are logged into CSR.
If VALIDATEFRAMES = STRICT or SecTAG's C bit is set and unknown SCI or no valid SA is in use from SADB after lookup, error are logged into InPktsNoSAError CSR.
If VALIDATEFRAMES = STRICT and packets enter through decryption lane without MACsec header, error are logged into InPktsNoTag CSR.
If packets are received with the SecTAG E bit set and C bit clear, packets are discarded and not delivered to the Controlled port.
If VALIDATEFRAMES = STRICT or C bit is set and SC is unknown, received packets are discarded.
If VALIDATEFRAMES = STRICT or C bit is set and SA is unused, received packets are discarded.
If REPLAYPROTECT = ENABLE and the received packets PN is less than MIN_PN from the SA entry, received packets are discarded.
If protectFrames = 1 and there is no valid SA for transmit SC, packets to be protected are discarded.
If the transmitted packets size including SecTAG and ICV is > TX_MAX_PCKT_BYTES CSR, the packet is discarded.
When a packet is discarded, the TVALID of the packet is suppressed for every data byte until the cycle where TLAST is observed. The port/stream ID (TID) of the discarded packet is matched against the incoming packet data byte to avoid dropping packets from a different port/stream.