Atlantis Land 111U ユーザーズマニュアル

 

 

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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 ADSL Router 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 ADSL Router tells the DHCP clients that it itself is the DNS 

server. When a computer sends a DNS query to the ADSL Router, the ADSL Router 

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 ADSL Router can pass 

the DNS servers to the computers and the computers can query the DNS server 

directly without the ADSL Router’s intervention. 

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.