TRex Skipping Latency Packet

[Mohsen Meamarian]

Hi,

I’m facing an issue where TRex doesn't recognize the latency packet, even though both packets are the same length and carry the same latency tag at the end:

ab 19 00 00 fe ff ff ff 85 69 c7 b2 43 ea 12 00

Here are the full hex dumps of both packets:

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Packet A (RX in my DUT):

00 15 4d 13 2e 13 10 70 fd 30 34 50 08 00 45 01 00 80 ff ff 00 00 40 11 04 d1 0a 00 00 01 00 d6 63 d5 08 69 08 68 00 08 00 00 01 ff 00 20 00 00 00 00 00 00 00 45 00 00 80 04 d2 00 00 40 11 00 00 0a 00 00 01 0a 00 00 02 08 69 08 68 00 08 00 00 78 00 04 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 ab 19 00 00 fe ff ff ff 85 69 c7 b2 43 ea 12 00

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Packet B (TX in my DUT toward Trex):

00 15 4d 13 2e 13 10 70 fd 30 34 50 08 00 45 00 00 6e 00 01 00 00 40 11 f7 2a c0 a8 01 01 c0 a8 01 02 1f 6b 56 08 00 00 00 00 01 01 00 00 00 00 00 00 00 00 00 45 00 00 80 04 d2 00 00 40 11 00 00 0a 00 00 01 0a 00 00 02 08 69 08 68 00 08 00 00 78 00 04 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 ab 19 00 00 fe ff ff ff 85 69 c7 b2 43 ea 12 00

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What could cause TRex to skip the latency pkt but recognize it in case I just mirror the rx pkt in my DUT? Could it be checking checksums or byte-shift that prevent it from detecting the latency tag?

Thanks,