Zhone 5100 참조 매뉴얼

CHAPTER 3
Interfaces

This feature provides a mapping capability from a specific port on the 5100/6100 VDR WAN IP 

port side to a different IP address or port on the Ethernet side of the same 5100/6100 VDR. 

With these commands, you can modify the IP address and port values of all packets in both 

directions.
Basic NAT functionality allows private IP address hosts on the LAN to access public Internet 

hosts.
With port and IPaddress mapping functionality, you can allow a client on the public Internet to 

access a server located on a private LAN subnet on the Ethernet side of the 5100/6100 VDR. 

This feature is useful for telnet, web server applications, and FTP access. 
With this mechanism, a specific WAN port is allocated for passing “through” traffic to the private 

Ethernet subnet. It provides security to the customer in that only specific known ports are open 

for public access. It is also consistent with the NAT philosophy of “hiding” the private network 

for IP space conservation and basic network security. The external client is unaware that the 

connection is not accessing a port on the VDR’s WAN interface. However, traffic directed at that 

port is internally forwarded to a host on the Ethernet subnet, as configured. This provides limited, 

but needed access to the private Ethernet subnet from the WAN side.
Static NAT maps, which differ from NAT port maps, and related commands follow the NAT 

port map commands. 

You can enable or disable NAT by issuing the set nat command.
Syntax: set nat <enable | disable>
Argument: 

enable | disable

enable allows you to activate NAT; disable allows you to deactivate 

NAT

Example:

In this example, NAT is enabled.

This command is used to specify a WAN port that is “connected” to the host on the private 

subnet. Note, that only specific traffic type (TCP or UDP) is “connected”. This helps in allowing 

only certain applications to have this kind of  “connection”.  Moreover, it possible to specify a 

totally different port number for the optional parameter: “inside_port”. This is very useful in that 

the user can reserve a totally different outside port for FTP traffic (e.g. 45555) instead of Port 21. 

This way the external client can access the WAN IP on port 45555 to FTP into the private host, 

and WAN IP on port 21 to FTP into the 5100/6100 VDR itself simultaneously. NAT takes care 

VPacket# set nat enable

VPacket#