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