Although NAT functionality is conceptually similar on J-series Service Routers and SRX-series services gateways, there are some configuration differences to note. On J-series devices, NAT is tied closely to policies. On SRX-series devices, NAT is not tied to policies and NAT configuration includes NAT-specific rules. Also, on SRX-series devices only, you must explicitly configure Proxy (Address Resolution Protocol) ARP.
The CLI configuration editors use slightly different commands for NAT on each device type. The following sections provide instructions for configuring NAT on both J-series Service Routers and SRX-series services gateways.