Number,Authentication Method,Reference
0,Reserved,
1,CHAP,[RFC7143]
2,SRP,[RFC7143]
3,KRB5,[RFC7143]
4,SPKM1 (OBSOLETE),[RFC7143]
5,SPKM2 (OBSOLETE),[RFC7143]
6-255,Reserved (Not assigned by IANA),[RFC7143]
256-65535,Unassigned,