Value,Protocol ID,References 0,RESERVED,[RFC2407] 1,PROTO_ISAKMP,[RFC2407] 2,PROTO_IPSEC_AH,[RFC2407] 3,PROTO_IPSEC_ESP,[RFC2407] 4,PROTO_IPCOMP,[RFC2407] 5,PROTO_GIGABEAM_RADIO,[RFC4705] 6-248,Unassigned, 249-255,Reserved for private use,