Information Inherited from First Fragments

Napatech Link™ Capture Software Features

Platform
Napatech SmartNIC
Content Type
Feature Description
Capture Software Version
Link™ Capture Software 12.5

Introduction

A fragment that is not a first fragment inherits information derived from the first fragment of the datagram in question if it is matched. This information is stored in the datagram lookup table.

Inherited information from extended packet descriptor 9

This information, which can be retrieved using HAL macros, is inherited from extended packet descriptor 9 of the first fragment:

  • If the hash calculation is valid (NT_NET_GET_PKT_HASH_VALID macro)
  • The number of the used hash key type (NT_NET_GET_PKT_HASH_TYPE macro)
  • The hash value (NT_NET_GET_PKT_HASH macro)
  • The packet color of the frame (NT_NET_GET_PKT_COLOR macro)
Note: For unmatched fragments, NT_NET_GET_PKT_HASH_VALID returns the value 1, NT_NET_GET_PKT_HASH_TYPE returns the value 30, NT_NET_GET_PKT_HASH returns a value derived from hash key type 30, and NT_NET_GET_PKT_COLOR returns the value 0.

Other inherited information

This information is also inherited from the first fragment:

  • The destination stream
  • If the frame must be discarded
  • If no filter matched
  • If the frame is a duplicate frame
Note: For unmatched fragments, the destination stream is derived from hash key type 30. The rest of the fields are 0.