Static Napt; Dynamic Nat; Dynamic Napt - Patton electronics SmartWare R.3.20 Software Configuration Manual

SmartWare Software Configuration Guide
Global Network
WAN
131.1.1.10 - 131.1.1.15

Static NAPT

Dynamic NAPT does not permit hosts on the global network to access hosts on the local network. Static
NAPT makes selected services (i.e. ports) of local hosts globally accessible. Static NAPT entries map global
addresses/ports to local addresses/ports. The global address can either be the address of the global interface or a
configured global NAPT address. Usually, the local and the global port of a static NAPT entry are the same;
however, they may be different.
WAN
131.1.1.1:80
131.1.1.3:23
Note
Be careful when mapping ports the SmartNode uses itself (e.g. Telnet,
TFTP) because the SmartNode might become inaccessible.

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 a dynamic NAT entry for the reverse
path. If a connection is 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).
Introduction
131.1.1.1 (Global Interface Address)
131.1.1.10 - 131.1.1.15 (Global NAT Address Pool)
Source Address modified
Figure 17. Dynamic NAPT
131.1.1.1 (Global Interface Address)
131.1.1.3 (Global NAPT Address)
Source Address modified
Destination Address modified
Figure 18. Static NAPT
(Local Interface Address) 192.168.1.1
Destination Address modified
(Local Interface Address) 192.168.1.1
11 • NAT/NAPT configuration
Local Network
LAN
192.168.1.30 - 192.168.1.39
LAN
192.168.1.20:80
192.168.1.20:23
124