Dns Server Address - ZyXEL Communications Prestige 128 Plus User Manual

Prestige 128+ ISDN Router
IP Pool Setup
The Prestige is pre-configured with a pool of 32 IP addresses starting from
192.168.1.33 to 192.168.1.64. This configuration leaves 31 IP addresses
(excluding the Prestige itself) in the lower range for other server machines, e.g.,
server for mail, FTP, telnet, web, etc., that you may have.

DNS Server Address

DNS (Domain Name System) is for mapping a domain name to its corresponding
IP address and vice versa, e.g., the IP address of www.zyxel.com is 204.217.0.2.
The DNS server is extremely important because without it, a user must know the
IP address of a machine before s/he can access it. The DNS server addresses that
you enter in the DHCP setup are passed to the client machines along with the
assigned IP address and subnet mask.
There are two ways that an ISP disseminates the DNS server addresses. The first
is for an ISP to tell a customer the DNS server addresses, usually in the form of
an information sheet, when s/he signs up. If your ISP does give you the DNS
server addresses, enter them in the DNS Server fields in DHCP Setup.
Some ISP's choose to pass the DNS servers using the DNS server extensions of
PPP IPCP (IP Control Protocol) after the connection is up. If your ISP did not
give you explicit DNS servers, chances are the DNS servers are conveyed
through IPCP negotiation. The Prestige supports the IPCP DNS server
extensions through the DNS proxy feature.
If the Primary and Secondary DNS Server fields in DHCP Setup are not
specified, i.e., left as 0.0.0.0, the Prestige tells the DHCP clients that it itself is
the DNS server. When a workstation sends a DNS query to the Prestige, the
Prestige forwards the query to the real DNS server learned through IPCP and
relays the response back to the workstation.
Please note that DNS proxy works only when the ISP uses the IPCP DNS server
extensions. It does not mean you can leave the DNS servers out of the DHCP
setup under all circumstances. If your ISP gives you explicit DNS servers, make
3-4 Internet Access