Billion 5100 Guía Del Usuario

and vice versa, for example, the IP address of www.billion.com is 204.217.0.2. The DNS

server is extremely important because without it, you must know the IP address of a machine

before you 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 gives you the DNS server addresses, enter them in the DNS Server

fields in DHCP Setup, otherwise, leave them blank.

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

BIPAC-5100/5100W 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, for instance,

left as 0.0.0.0, the BIPAC-5100/5100W tells the DHCP clients that it itself is the DNS server.

When a computer sends a DNS query to the BIPAC-5100/5100W, the BIPAC-5100/5100W

forwards the query to the real DNS server learned through IPCP and relays the response back

to the computer.

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 sure that you enter their IP addresses in the

DHCP Setup menu. This way, the BIPAC-5100/5100W can pass the DNS servers to the

computers and the computers can query the DNS server directly without the

BIPAC-5100/5100W’s intervention.

4.3 DNS Server Address Assignment

Use DNS (Domain Name System) to map a domain name to its corresponding IP address and

vice versa. The DNS server is extremely important because without it, you must know the IP

address of a computer before you can access it.

There are two ways that an ISP disseminates the DNS server addresses.

1. The ISP tells you the DNS server addresses, usually in the form of an information sheet,

when you sign up. If your ISP gives you DNS server addresses, enter them in the DNS Server

fields in DHCP Setup.

2. Leave the DNS Server fields in DHCP Setup blank (for example 0.0.0.0). The

BIPAC-5100/5100W acts as a DNS proxy when this field is blank.