What Are the Differences Between NAT Server and NAT Static Modes?

For the access from the public network to the private network, the NAT server and NAT static modes are the same. For the access from the private network to the public network, the NAT server mode translates only the IP address, while the NAT static mode translates both the IP address and port.

<Huawei> system-view
[Huawei] interface gigabitethernet 0/0/1
[Huawei-GigabitEthernet0/0/1] ip address 1.1.1.1 24
[Huawei-GigabitEthernet0/0/1] nat server protocol tcp global current-interface 3000 inside 10.1.1.100 1000 

Figure 5-32 Diagram of the NAT server mode

For the access from the private network to the public network, the When the NAT server proactively accesses the Internet, NAT server mode translates only the IP address. That is, when the source IP address of the traffic matches the private IP address in the NAT server rule, the NAT server mode translates the IP address regardless of the port number.

<Huawei> system-view
[Huawei] interface gigabitethernet 0/0/1
[Huawei-GigabitEthernet0/0/1] ip address 1.1.1.1 24
[Huawei-GigabitEthernet0/0/1] nat static protocol tcp global current-interface 3000 inside 10.1.1.100 1000 

Figure 5-33 Diagram of the NAT static mode

For the access from the private network to the public network, the NAT static mode translates both IP address and port.

The enterprise requires that private users can access the public server and public users can access the private server. If both the NAT server and Easy IP functions are configured on the router, since the NAT server mode translates only the IP address for the access from the private network to the public network, flow tables may fail to be established. In this case, you are advised to change NAT server to NAT static.