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