ZyXEL nbg-4615 Guida Utente

Chapter 18 DHCP Server

NBG4615 User’s Guide

First DNS Server

Second DNS 
Server 

Select From ISP if your ISP dynamically assigns DNS server 
information (and the NBG4615's WAN IP address). The field to the 
right displays the (read-only) DNS server IP address that the ISP 
assigns. 

Select User-Defined if you have the IP address of a DNS server. 
Enter the DNS server's IP address in the field to the right. If you chose 
User-Defined, but leave the IP address set to 0.0.0.0, User-Defined 
changes to None after you click Apply. If you set a second choice to 
User-Defined, and enter the same IP address, the second User-
Defined changes to None after you click Apply. 

Select DNS Relay to have the NBG4615 act as a DNS proxy. The 
NBG4615's LAN IP address displays in the field to the right (read-
only). The NBG4615 tells the DHCP clients on the LAN that the 
NBG4615 itself is the DNS server. When a computer on the LAN sends 
a DNS query to the NBG4615, the NBG4615 forwards the query to the 
NBG4615's system DNS server (configured in the WAN > Internet 
Connection screen) and relays the response back to the computer. 
You can only select DNS Relay for one of the three servers; if you 
select DNS Relay for a second or third DNS server, that choice 
changes to None after you click Apply. 

Select None if you do not want to configure DNS servers. If you do 
not configure a DNS server, you must know the IP address of a 
computer in order to access it.

Apply

Click Apply to save your changes back to the NBG4615.

Cancel

Click Cancel to begin configuring this screen afresh.

Table 63   Network > DHCP Server > Advanced (continued)