Value,Group Controller Authentication Method,Reference
0,Reserved,[RFC-ietf-ipsecme-g-ikev2-21]
1,Implicit,[RFC-ietf-ipsecme-g-ikev2-21]
2,Digital Signature,[RFC-ietf-ipsecme-g-ikev2-21]
3-1023,Unassigned,
1024-65535,Reserved for Private Use,[RFC-ietf-ipsecme-g-ikev2-21]