Black Box IT Pro LNA1000A, Руководство пользователя

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Black Box® IT Pro™ User Manual 211
Domain Name Services
How the DNS System Works
DNS Hierarchy
The Internet DNS server network is arranged as a hierarchy, in which a single ‘root’ domain,
sometimes called dot (‘.’), links to the set of top-level domains (such as
.com and .org ). In
turn, each of the top-level domains contains a link to each of the second-level domains (such
as
example.com
and
mydomain.org
). Third- and fourth-level domains are less common
and are used in large organizations like universities.
You will most likely publish a second-level domain name such as example.com . When you
do that, your DNS server (if enabled) automatically publishes the names inside
exam-
ple.com
, such as
www.example.com
and
mail.example.com
.
Domain Registrars
However, there is still a part that must be done manually: in this example, you have to create
a link on the
.com server to ask your second-level domain to be referred to the IP address of
your Black Box® IT Pro™. To do this, you need to visit a Domain Registrar (such as
www.easydns.com
or
www.opensrs.org
) to make sure your domain name isn’t already
being used by someone else, and give them the outside IP address of your Black Box® IT
Pro™.
Please Note: In order to register a domain name, your Black Box® IT Pro™ must have a static IP
address. Most ISPs provide this service for an additional fee. DDNS can be used in place of a static IP
address. Refer to
Dynamic DNS in this chapter for more information.
After you enable your Public DNS Server and register with a Domain Registrar, people
should be able to look up the IP address associated with your domain name. To test this,
select
WWW from the Server Setup menu, and select Yes in the Enable WWW Server field.
Then ask a friend outside the local network if they can view your domain.