FortiOS supports the following RFCs:
BGP
IPv6
SNMP
Cryptography
IS-IS
SSH
DHCP
LDAP
SSL
Diffserv
TCP
DNS
NAT
TLS
ICMP
OSPF
VPN
IP
PPP
Wireless
IP multicast
RADIUS
Other protocols
IPsec
RIP
Miscellaneous
IPv4
SIP