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Spirent KB Article
Doc ID: FAQ19535
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Spirent TestCenter: GUI reporting - 'Rx TCP Checksum Error' and 'Rx IPv4 Checksum Error' at 400G (PX3-400G-T2)
Based on the description the use case is running line rate non-sig traffic, the hardware cannot store non-sig traffic without dropping packets and incurring buffer overrun conditions. The CPU is required to upload, process, calculate stats for all these frames. When buffer overflow occurs, frames are truncated or concatenated - we think this could be a reason for the checksum errors.
When signature is enabled, the FPGA processes the packets instead of the CPU. There is no buffer overflow in this case and no error detected. Please consider this option (adding signature) to be a viable workaround for the customer.
Small 64B packets will fit nicely into the buffers and overwrite other 64B packets in the same spot when overrun occurs. This is likely a reason why Fixed Mode might appear ok; it is a false positive.
The random FS will fill the buffer uniquely and buffer overrun may not align with the previous stored frames; hence leading to more checksum errors.
Summary: this use case may not be properly supported. Please lower the frame rate of non-sig traffic to < 1% (of 400Gbps) and check if the same failure happens.
Product : Spirent TestCenter