TP-LINK TD-8817 User Manual

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TD-8817 
ADSL2+ Ethernet/USB Modem Router User Guide 
 
34 
  Virtual Circuit: Enter Virtual Circuit Index that you plan to setup for the NAT function. 
  NAT Status: This field shows the current status of the NAT function for the current VC. You 
can go to the previous screen (shown in Figure 4-6) to activate the function. 
  Number of IPs; This field is to specify how many IPs are provided by your ISP for current VC. 
It can be single IP or multiple IPs. We select Multiple to explain. 
 
Note: 
For VCs with single IP, they share the same DMZ and Virtual servers; for VCs with multiple IPs, 
each VC can set DMZ and Virtual servers. Furthermore, for VCs with multiple IPs, they can define 
the Address Mapping rules; for VCs with single IP, since they have only one IP, there is no need 
to individually define the Address Mapping rule. 
4.4.3.1.  DMZ 
Choose “Advanced SetupNATDMZ” in Figure 4-22, you can configure the DMZ host in the 
next screen. A DMZ (demilitarized zone) is a host between a private local network and the outside 
public network. It prevents outside users from getting direct access to a server that has company 
data. Users of the public network outside the company can access to the DMZ host. 
 
Figure 4-23 
  DMZ Host IP Address: Enter the specified IP Address for DMZ host on the LAN side. 
4.4.3.2.  Virtual Server 
Choose “Advanced SetupNATVirtual Server” in Figure 4-22, you can configure the Virtual 
Server in the next screen.   
The Virtual Server is the server or server(s) behind NAT (on the LAN), for example, Web server or 
FTP server, that you can make visible to the outside world even though NAT makes your whole 
inside network appear as a single machine to the outside world.