Editing DNS Settings
This document explains
What
is DNS?
DNS can be considered something similar
to a phone book. When you move from
one location to another, your name stays
the same, but your phone number may
change. In order to point your name
to the new phone number, you must contact
the telephone service provider so they
assign you the new phone number and
update all directory information to
reflect you as pointing to this new
phone number.
In this way, the IP number can be compared
to a phone number: When someone calls
http://www.example.com/, your ISP looks
at the DNS server, and asks "how
do I contact example.com?" The
DNS server responds: "It can be
found at 198.105.232.4". As the
Internet understands it, this can be
considered the phone number for the
server, which houses the http://www.example.com
web site.
The DNS records for your domain are
kept on your hosting server in the place
called DNS zone. When you register a
domain by means of the control panel,
all DNS records are automatically created
for you, but in some rare cases you
may need to add custom records to your
DNS zone. An example would be when you
want all email to be processed by an
external mail server rather than by
the built-in mail system. However, such
user intervention requires knowledge
of DNS configuration and clear understanding
of what is to be done.
How
Do I Create Custom DNS records?
To create a custom record to your DNS
zone, do the following:
- Click Domains in your control
panel home page.
- Select the domain if you have more
than one.
- On the page that appears, click
the Edit icon in the DNS
Configuration field:
- This link will take you to the DNS
Configuration page:
On this page you can see several
blocks of DNS records. Some are
built-in and non-removable; others
are user-defined and can be deleted.
Built-in MX records require special
consideration: they can be removed
by disabling mailservices for this
domain., but all e-mail resources,
including mailboxes, forwarders,
and autoresponders will also be
deleted. The removal of H-Sphere
2.x email services was made possible
to enable the use of e-mail services
provided by other mail servers.
You can add any type of DNS records
by clicking an appropriate link.
You will be asked to enter corresponding
DNS data.
Adding
Custom A Records
Normally, A records are used to map
domain names and web server IP's.
If you have selected A record, the
following page appears:
- Name: enter the string to
map to the web server.
- TTL: set how many seconds
will elapse before the record is refreshed
in the DNS cache.
- Data: enter the IP of the
web server.
WARNING: Please pay attention to $ORIGIN
when you add an A record.
Adding
Custom MX Records
Custom MX records should be added when
you want to use your external mail servers
to process your e-mail. To use your
external servers instead of those
you get by default, you need to disable
mail service on the Domain Settings
page of your control panel. To use the
default mail servers in addition
to those you get by default, you need
to keep mail service enabled in the
control panel.
The priority of the custom MX record
will define whether your external servers
will act as secondary or primary. For
instance, if you set the priority of
the custom MX record higher than 10
(e.g. 11), your external mail server
will be used as secondary. If you set
the priority of the custom MX record
lower than 10 (e.g. 9), your external
mail server will be used as primary.
In the latter case, your mail will be
sent to your external mail server until
it goes down or becomes otherwise inaccessible.
Then the default mail server will take
over.
When you enable mail service in the
control panel, an MX record is created
automatically in the DNS zone. If mail
service is disabled, this built-in MX
record remains in the DNS zone, and
you can remove it manually using the
control panel interface.
If you have selected MX record, the
following page appears:
- Name: your local domain name.
If you leave the Name field
blank, all mail will be redirected
for the base zone.
- Data: the priority of the
record and mail domain name (not the
IP) mail will be forwarded to.
IMPORTANT: To add an MX record for
the base domain, leave the Name
field empty.
Adding
Custom CNAME Records
Finally, CNAME records are used to
map aliases with domain names.
If you have selected CNAME record,
the following page appears:
- Name: The alias you give
to the real host name.
- TTL: set how many seconds
will elapse before the record is refreshed
in the DNS cache.
- Data: The real name of the
host you create an alias to. This
must be an official host name. It
cannot be an alias. A CNAME-record
should always point to an A-record
to avoid circular references.
WARNING: Please pay attention
to $ORIGIN when you add a CNAME record.
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