Hash Key Type 12: 5-Tuple SCTP

Napatech Link™ Capture Software Features

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

Hash key data

Hash key type 12 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

The hash key data is not sorted for hash key type 12. 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 SCTP source port number is always placed in the lower 16 bits of hash key data word 8, and the SCTP destination port number is always placed in the upper 16 bits of hash key data word 8.

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 12.

Illustration for IPv4 packets

This figure illustrates hash key type 12 for IPv4 packets.

5 - tuple SCTP hash key SCTP packet header IPv 4 packet header Ver . & IHL T o S Total l ength Identification F Fragment offset TTL Prot . Header checksum Source address Destination address Options 0 4 8 12 16 20 Source port Destination port Verification tag Adler 32 checksum 0 4 8 16 - bit SCTP destination port 16 - bit SCTP source port 32 - bit SCTP verification tag 32 - bit IPv 4 source address 32 - bit IPv 4 destination address 0 1 Hash key data word 2 0 0 0 0 0 0 3 4 5 6 7 8 9

Illustration for IPv6 packets

This figure illustrates hash key type 12 for IPv6 packets.

5 - tuple SCTP hash key SCTP packet header Source port Destination port Verification tag Adler 32 checksum 0 4 8 16 - bit SCTP destination port 16 - bit SCTP source port 32 - bit SCTP verification tag 8 9 128 - bit IPv 6 source address 128 - bit IPv 6 destination address 0 , 1 , 2 & 3 Hash key data word 4 , 5 , 6 & 7 IPv 6 packet header Ver . & Pri . Flow label Length Next header Hop limit Source address Destination address 0 4 8 12 16 20 24 28 32 36 40

Validity

Hash key type 12 is valid for frames containing an IPv4 packet or an IPv6 packet with an SCTP packet as payload.