Hash Key Type 11: 3-Tuple GREv0 Sorted

Napatech Link-Capture™ Software Features

Intel® PAC
Napatech SmartNIC
Content Type
Feature Description
Capture Software Version
Link™ Capture Software 12.9

Hash key data

Hash key type 11 is a 3-tuple where the hash key data is the contents of these packet header fields:

  • 32-bit IPv4 / 128-bit IPv6 source address
  • 32-bit IPv4 / 128-bit IPv6 destination address
  • 32-bit GREv0 key

For hash key type 11, the source and destination IP addresses are XORed together. The XORed value is stored in hash key data word 0 / 0 – 3 whereas 4 / 4 – 7 are zeroed. This means that frames sent from IP address A to IP address B will generate the same hash value as frames sent from IP address B to IP address A.

Hash key data word 8 is always the GREv0 key.

For IPv4 packets, hash key data words 1 – 3, 5 – 7 and 9 are all zeros for hash key type 11. For IPv6 packets, hash key data word 9 is all zeros for hash key type 11.


Hash key type 11 is valid for frames containing an IPv4 packet or an IPv6 packet with a GREv0 packet as payload.