Value,Type,Reference
0,Reserved,[RFC8263]
1,REKEY_ACK_KEK_SHA256,[RFC8263]
2,REKEY_ACK_LKH_SHA256,[RFC8263]
3,REKEY_ACK_KEK_SHA512,[RFC8263]
4,REKEY_ACK_LKH_SHA512,[RFC8263]
5-128,Unassigned,
129-255,Private Use,