Stateless NAT, occasionally maligned as dumb NAT [31], is the simplest form of NAT. It involves rewriting addresses passing through a routing device: inbound packets will undergo destination address rewriting and outbound packets will undergo source address rewriting. […]

[…]

NAT with iproute2 can be used in conjunction with the routing policy database (cf. RPDB) to support conditional NAT, e.g. only perform NAT if the source IP falls within a certain range. See Section 5.3.3, “Conditional Stateless NAT”.

Via #ldn