Error Indications

Feature Set N-ANL9

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Napatech SmartNIC
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Feature Description

Frame-based error indications

These frame-based errors can be indicated in the extended packet descriptor 9:

  • Ethernet small frame error

    If the ISL, Ethernet and VLAN/MPLS frame decode shows that the frame is too small for the applied protocols, an Ethernet small frame error is indicated in the frame decoder status word.

  • Ethernet large frame error

    If the frame is a large frame (see Large frames), an Ethernet large frame error is indicated for the frame. It is indicated in the frame decoder status word.

FCS error flag

A frame is flagged for FCS violation if:

  • It is smaller than 18 bytes, that is it is not a well-formed Ethernet frame and is considered a fragment.
  • It is larger than or equal to 18 bytes but smaller than or equal to 10,000, and the last 4 octets do not match the recalculated frame CRC.
  • It is larger than 10,000 bytes, that is it is a hard-sliced frame.
  • It has a code violation.
  • It has an alignment error.

FCS errors are always flagged in the standard packet descriptor (see DN-0449), but are not always counted in the statistics (see Statistics).

Hard-sliced flag

A frame is flagged for hard-slicing if the frame length is larger than 10,000 bytes.

Code violation flag

A frame is flagged for code violation if it contains code violation bit errors.