Hash Key Type 13: 5-Tuple SCTP Sorted

Napatech Link-Capture™ Software Features

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

Hash key data

Hash key type 13 is a 5-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
  • 16-bit SCTP source port number
  • 16-bit SCTP destination port number
  • 32-bit SCTP verification tag

For hash key type 13, the source and destination IP addresses are XORed together, and the XORed value is stored in hash key data word 0 / 0 – 3 whereas 4 / 4 – 7 are zeroed. The source and destination port numbers are also XORed together, and the XORed value is stored in the upper 16 bits of hash key data word 8 whereas the lower 16 bits of hash key data word 8 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 9 is always the SCTP verification tag.

For IPv4 packets, hash key data words 1 – 3 and 5 – 7 are all zeros for hash key type 13.

Validity

Hash key type 13 is valid for frames containing an IPv4 packet or an IPv6 packet with an SCTP packet as payload.