"NAT is a firewall"
lorenetworkingsecurity
The belief that address translation is a security control. NAT hides topology as a side effect, but it filters nothing by policy - a stateful firewall does.
The confusion comes from home routers bundling both; RFC 4864 exists partly to untangle 'NAT security' from actual protection, and IPv6 without NAT reopened the debate.
Disputed / commonly mistold A popular version of this story is inaccurate - see the note above.
Also known as: nat security myth
Sources
- IETF RFC 4864 - Local Network Protection for IPv6 (2007)
- IETF RFC 2663 - IP NAT terminology and considerations (1999)