PLANET SG-1000 - Manual (Page 137)

Chapter 11
Virtual Server
The real IP address provided from ISP is always not enough for all the users when the
system manager applies the network connection from ISP. Generally speaking, in order
to allocate enough IP addresses for all computers, an enterprise assigns each computer a
private IP address, and converts it into a real IP address through SG-1000’s NAT
(Network Address Translation) function. If a server that provides service to WAN
network is located in LAN networks, external users cannot directly connect to the server
by using the server’s private IP address.
The SG-1000’s Virtual Server function can solve this problem. A Virtual Server has set
the real IP address of the SG-1000’s WAN network interface to be the Virtual Server IP.
Through the Virtual Server function, the SG-1000 translates the Virtual Server’s IP
address into the private IP address in the LAN network.
Virtual Server owns another feature know as one-to-many mapping. This is when one
real server IP address on the WAN interface can be mapped into four LAN network
servers provide the same service private IP addresses. This option is useful for Load
Balancing, which causes the Virtual Server to distribute data packets to each private IP
addresses (which are the real servers) by session. Therefore, it can reduce the loading of
a single server and lower the crash risk. And can improve the work efficiency.