Interface-based source NAT uses the outgoing interface address as the translated source address and commonly relies on Port Address Translation to allow many internal hosts to share that single interface IP address. Juniper describes source NAT as translating private addresses to public routable addresses and specifically supports translating many addresses to a single address or smaller address block using port translation. Static NAT is a fixed one-to-one mapping and does not normally perform PAT. Source NAT with address shifting maps one address block to another and is not the interface overload method. Destination NAT without port forwarding changes the destination address, not the source address and port for outbound sharing.