Dynamic Nat; Static Nat - Patton electronics SmartNode Series Software Configuration Manual

11 • NAT/NAPT configuration SmartWare Software Configuration Guide

Dynamic NAT

NAT only modifies addresses but not ports. Dynamic NAT assigns a global address from a global NAT address
pool each time a local host wants to access the global network. It creates of dynamic NAT entry for the reverse
path. Is a connection idle for some time (2 minutes), the dynamic NAT entry is removed. Should Dynamic
NAT run out of global addresses, it lets Dynamic NAPT handle the connection (which may lead to an unex-
pected behavior).
Dynamic NAT is particularly useful for protocols that do not build on UDP or TCP but directly on IP (e.g.
GRE, ESP), see also section "NAPT Traversal".
Figure 27. Dynamic NAT

Static NAT

Dynamic NAT does not permit hosts on the global network to access hosts on the local network. Static NAT
makes local hosts globally accessible. Static NAT entries map global addresses to local addresses. The global
address must be a configured global NAT address. It cannot be the address of the global interface since this
would break connectivity to the SmartNode itself.
Static NAT is particularly useful for protocols that do not build on UDP or TCP but directly on IP (e.g. GRE,
ESP), see also section "NAPT Traversal".
Figure 28. Static NAT
122 Introduction