Hash Key Type 8: 5-Tuple

Napatech Link-Capture™ Software Features

Platform
Napatech SmartNIC
Content Type
Feature Description
Capture Software Version
Link™ Capture Software 12.11

Hash key data

Hash key type 8 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 UDP, TCP or SCTP source port number
  • 16-bit UDP, TCP or SCTP destination port number
  • 8-bit IPv4/IPv6 protocol number / next header

For IPv4 packets, hash key data word 0 is always the IPv4 source address, and hash key data word 4 is always the IPv4 destination address. For IPv6 packets, hash key data words 0 – 3 are always the IPv6 source address, and hash key data words 4 – 7 are always the IPv6 destination address. This means that frames sent from IP address A to IP address B will generate a hash value different from frames sent from IP address B to IP address A (if address A and B are different).

Note: The source and destination addresses and ports can be swapped (see Tuple Swap).

The UDP/TCP/SCTP source port number is always placed in the lower 16 bits of hash key data word 8, and the UDP/TCP/SCTP destination port number is always placed in the upper 16 bits of hash key data word 8.

The IPv4/IPv6 protocol number / next header is placed in a separate 8-bit word.

For IPv4 packets, hash key data words 1 – 3, 5 – 7 and 9 are all zeros for hash key type 8 For IPv6 packets, hash key data word 9 is all zeros for hash key type 8..

Illustration for IPv4 packets

This figure illustrates hash key type 8 for IPv4 packets.

5-tuple hash key for IPv4

Illustration for IPv6 packets

This figure illustrates hash key type 8 for IPv6 packets.

5-tuple hash key for IPv6

Validity

Hash key type 8 is valid for frames containing an IPv4 packet or an IPv6 packet with a UDP, a TCP or an SCTP packet as payload.