}
One2One (One to One):
It indicates static network address translation. It is always
referred to as Basic NAT, which provides a one to one mapping between an internal
and an external IP address. In this type of NAT, IP address need be changed, but port
needn
’t.
One to One NAT can be used to allow the outside users to access a LAN server: In
the local network, the LAN server still use the private IP address, which is provided to
the LAN hosts to access; and on the Internet, the Device will assign an external IP
address to the local server, then the outside users can using this external IP address
to access the server through the Device.
EasyIP:
It indicates network address and port translation (NAPT). Since it is the most
common type of NAT, it is often simply referred to as NAT. NAPT provides
many-to-one mappings between multiple internal IP addresses and a single external
IP addresses, that is, these multiple internal IP addresses will be translated to the
same external IP address. In this type of NAT, to avoid ambiguity in the handling of
returned packets, it must dynamically assign a TCP/UDP port to an outgoing session
and change the packets
’ source port to the assigned port before forwarding them.
Besides, the Device must maintain a translation table so that return packets can be
correctly translated back.
When you obtain multiple public IP addresses from your ISP, you can create more
than one NAT rule for each type of NAT. In actual network environment, different types
of NAT rules are often used together.
5.1.1.9 NAT Rule List
Figure 5-6 NAT Rule list
Add a NAT Rule:
Click
the
Add
button to go to the setup page, and then
configure it, lastly click the
Save
button.
