ZyXEL Communications ADSL2+4 用户手册
Chapter 7 LAN Setup
P-660H-T1v3s User’s Guide
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7.6.3 DNS Server Addresses
DNS (Domain Name System) maps 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. The DNS
server addresses you enter when you set up DHCP are passed to the client
machines along with the assigned IP address and subnet mask.
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. The DNS
server addresses you enter when you set up DHCP 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 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 the DHCP Setup screen.
• Some ISPs choose to disseminate the DNS server addresses using the DNS
server extensions of 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 P-660H-T1v3s supports the IPCP DNS
server extensions through the DNS proxy feature.
If the DNS Server fields in the DHCP Setup screen are set to DNS Relay, the
If the DNS Server fields in the DHCP Setup screen are set to DNS Relay, the
P-660H-T1v3s tells the DHCP clients that it itself is the DNS server. When a
computer sends a DNS query to the P-660H-T1v3s, the P-660H-T1v3s acts as a
DNS proxy and 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
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 screen.
7.6.4 LAN TCP/IP
The P-660H-T1v3s has built-in DHCP server capability that assigns IP addresses
and DNS servers to systems that support DHCP client capability.
and DNS servers to systems that support DHCP client capability.
IP Address and Subnet Mask
Similar to the way houses on a street share a common street name, so too do
computers on a LAN share one common network number.
computers on a LAN share one common network number.
Where you obtain your network number depends on your particular situation. If
the ISP or your network administrator assigns you a block of registered IP
addresses, follow their instructions in selecting the IP addresses and the subnet
mask.
the ISP or your network administrator assigns you a block of registered IP
addresses, follow their instructions in selecting the IP addresses and the subnet
mask.
If the ISP did not explicitly give you an IP network number, then most likely you
have a single user account and the ISP will assign you a dynamic IP address when
the connection is established. If this is the case, it is recommended that you select
a network number from 192.168.0.0 to 192.168.255.0 and you must enable the
have a single user account and the ISP will assign you a dynamic IP address when
the connection is established. If this is the case, it is recommended that you select
a network number from 192.168.0.0 to 192.168.255.0 and you must enable the