ZyXEL Communications P-661H Series, Руководство пользователя, Страница: 97 / 383

P-661H/HW Series User’s Guide
Chapter 5 LAN Setup 97
5.1.4 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.
• 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.
• The ZyXEL Device acts as a DNS proxy when the Primary and Secondary DNS Server
fields are left as 0.0.0.0 in the DHCP Setup screen.
5.2 LAN TCP/IP
The ZyXEL Device has built-in DHCP server capability that assigns IP addresses and DNS
servers to systems that support DHCP client capability.
5.2.1 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.
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.
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 Network Address Translation (NAT)
feature of the ZyXEL Device. The Internet Assigned Number Authority (IANA) reserved this
block of addresses specifically for private use; please do not use any other number unless you
are told otherwise. Let's say you select 192.168.1.0 as the network number; which covers 254
individual addresses, from 192.168.1.1 to 192.168.1.254 (zero and 255 are reserved). In other
words, the first three numbers specify the network number while the last number identifies an
individual computer on that network.
Once you have decided on the network number, pick an IP address that is easy to remember,
for instance, 192.168.1.1, for your ZyXEL Device, but make sure that no other device on your
network is using that IP address.
The subnet mask specifies the network number portion of an IP address. Your ZyXEL Device
will compute the subnet mask automatically based on the IP address that you entered. You
don't need to change the subnet mask computed by the ZyXEL Device unless you are
instructed to do otherwise.