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