DNS Settings

DNS Settings

This section contains information about making DNS changes for your website. It includes information for beginners, a quick guide to DNS, an explanation (with examples) of A, CNAME, NS and MX records, and changing DNS settings.

Information for Beginners

The ability to change the DNS configuration of a website is an important feature. Incorrect changes in DNS settings can cause the entire website to shut down for an extended period of time. This is because changes in DNS are not instantaneous (see below). If you make a mistake, no one will probably be able to connect to your site (including you). If you fix it, it can take up to 72 hours to recover.

There are several ways to prevent errors:

1. Read this article carefully.
2. Make sure you understand what the A, CNAME, NS, and MX entries affect.
Contact your web hoster for additional help and guidance.
4. Do not make major changes without assistance.

With a little practice, you will find that it is very easy to make changes to the DNS.

DNS Tutorial

DNS (domain name servers) tell computers how to find each other over the Internet. When you enter an address in your browser, your Internet Service Provider checks its Domain Name Server (DNS) to determine where to send you.

http://www.domain.com —> Check with DNS —> DNS says domain.com = 192.168.0.1 —> You get to the website.

Why is this happening?

This is because your domain name will not always have the same IP address. Every server on the Internet has an IP address (a numeric address, as an example, a phone number). Every time you change web hosts, you change servers (and therefore change IP addresses).

Domain name servers keep track of your domain name and which IP address (server) it should point to.

Why should I put the name servers (DNS) of my web host in my domain record?

As you learned above, name servers tell the Internet how to find you. When you edit name servers in your domain record, you tell the Internet which name server provides the most relevant directions. If you don’t change the name servers in your domain record (let’s say you use the DNS of your old web host), then your website will point to a server that doesn’t host your domain. Or, if the old web host removed you from their DNS, your domain will not work at all.

Why does it take so long for my site to start working?

When you change web hosts (addresses) or register a domain for the first time, the new DNS information should reach any other name server (DNS) on the Internet. Your site can get up and running in as little as 4 hours, but the average wait time is 24-72 hours. This delay occurs because most name servers (DNS) are configured to periodically check for updates. This does not happen immediately after making new domain settings. Periodic checking is done because continuous checking often slows down the server.

Why does my domain point to my old host, even though I deleted my account with them?

There may be several reasons for this:

1. Their name servers are still in your domain entry.
Solution: Update the domain record by specifying new web host name servers (DNS).

2. They have not removed your domain record from their name servers.
Solution : ask them to remove your domain record or use solution #1 if you have new web hosting.

3. the DNS update has not yet happened. This will happen even with the DNS of your new web host in your domain record.
Solution: wait 24-72 hours and contact your new web host if the problem persists.

Why can some people get to my new site and I can’t?

Their ISP has more up-to-date DNS records than your ISP. Be patient, as your new site will appear within 24-72 hours.

Is there any way to view/access my site even though the DNS has not changed yet?

Yes. You can access your site at http://ip.address/~username and access the control panel at http://ip.address:2222. If you don’t know the server IP address, check with your hosting provider.

Changing DNS settings

To open the DNS settings menu, click the “Accounts” icon on the main menu of the Control Panel, click the “Manage DNS” link.

From there you will see all the DNS records of your site.

Above is an example of DNS settings for example.com. The following sections provide information about changing A, CNAME, NS, MX, and PTR records. It is also important to understand how the control panel handles host names.

Important note: There are two ways to enter a host name:

1. The full hostname followed by a period: full.hostname.com.
2. one subdomain.

For example, the first entry in the table above can read:

admin A 91.203.6.59
or
admin.example.com. A 91.203.6.59

Both entries do the same thing. The sections below may discuss only one method, but either method is acceptable.

Hint: If you don’t know how to enter an entry, refer to the existing entries in the table for guidance.

Explanation of entries: A, CNAME, NS, MX and PTR.

A Records

Address entries (A) direct the host name to a numeric IP address. For example, if you want tuthost.example.com to point to your ip (for example, 91.203.4.22), you must enter an entry that looks like this

Note. If you have an IPv6 IP address, use the AAAA entry instead.

Important: You must put a period after the host name. Do not put dots after IP addresses.

CNAME record

CNAME allows a machine to be known by one or more host names. First there must be an entry A, and this is known as the canonical or official name. For example:

yourdomain.com. A 192.168.0.1

Using CNAME, you can point other host names to the canonical (A record) address. For example:

ftp.example.com. CNAME example.com.
mail.example.com. CNAME example.com.
ssh.example.com. CNAME example.com.

CNAME records allow you to access your domain via ftp.example.com, mail.example.com, etc. Without a proper CNAME record, you will not be able to connect to your server using such addresses.

Entering CNAME records

If we wanted home.example.com to point to example.com, we could enter the entry in two ways:

The first method allows you to simply enter a subdomain. Do not put a period after the subdomain name.

The second method requires you to enter a full hostname followed by a period.

NAMESERVER (NS) records

NS records point to authoritative name servers for a domain.

Important: Changing NS records may cause your site to stop working. As a rule, it is not necessary to change NS records.

Entering an NS record

Enter two new name server entries to match the example in the table above. Make sure that the name server host name is followed by a dot, as in this example:

Be sure to dot the name server hostname in the NS record (ns1.example.com., not ns1.example.com).

MX records

Free mail services, such as Everyone.net, require changes to the MX records section in order for their software to work. This change allows you to send mail destined for your domain to their server. Note that changing MX records may interfere with your current POP3 accounts, relay servers, autoresponders, and mailing lists.

To add an MX record, enter the hostname followed by the dot provided to you by your email provider. Then select a priority level (usually 10) from the drop-down list on the right. The priority level will also be given to you by your email service provider. Click Add.

Note. Be sure to put a dot at the end of the hostname.

To restore the original MX settings, type example.com. and priority 0 after deleting another MX record.

PTR records

Pointer records (PTRs) are used for reverse lookups. For example, to convert 192.168.0.1 to www.example.com, the entry should look like this

1.0.168.192.in-addr.arpa PTR www.example.com

Note. The IP address changes in the first field. Use a period after your hostname (second field).

The “in-addr-arpa” method is the most commonly used.

Important: PTR entries only work if your site has its own IP address.

Note: PTR entries are only effective if named.conf is manually edited and appropriate zone information is added. This can only be done by the root user (server administrator).

TXT records

Text records (TXT) are originally used to store new types of information. This information can be any text. The entry will look like this:

Note. TXT is often used to configure a Senf Policy Framework (SPF) entry, which is used to verify valid email sources from the domain.
Example:

SRV records

SRV records provide a standard way to allow services to use different values, and for a program to determine what those connection values are.
Example:

_sip._tcp.example.com.
86400 IN SRV 0 5 5060
sipserver.example.com.

The red part goes to the left side of the SRV record in the DA, and the blue part goes to the right side (the DA sets the TTL for you automatically)

Thered part contains the service, protocol and name in that order, separated by a dot ‘.

In the above example, the values look like this:

• service: _sip
• Protocol: _tcp
• Name: example.com.
• priority: 0
• weight: 5
• port: 5060
• target: sipserver.example.com.

Note that the value “name” will always correspond to the name of the zone. Thus, the 2 values on the left are equivalent, and either one can be used:

• _sip._tcp.example.com.
• _sip._tcp

where any left-handed value that does not end with a dot ‘.’ will add the zone name to the end.

“Target” value can be any domain value, but it must be resolved using an A or CNAME record. The same rule applies for a value ending with a dot, and it will be binding if the target is another domain name.

Other entries

There are other entries that are disabled by default in DirectAdmin. You can, however, enable them manually.

CAA RECORDS

DNS Certification Authority Authorization (CAA) is an Internet security policy mechanism that uses resource records in the Domain Name System (DNS) to allow domain name owners to specify which certificate authorities are authorized to issue certificates for that domain and what types of certificates they use.

You can manually enable the CAA entry in DirectAdmin by following this guide.

TLSA RECORDS

TLSA records are used to specify the keys used on TLS domain servers.

The TLSA record identification (record name) consists of 3 parts:

• Port number: the number of the port that the TLS server is listening on.
• Protocol: the protocol used (udp, tcp, sctp or user defined).
• Server Host Name: The host name of the TLS server.

You can manually enable the TSLA entry in DirectAdmin by following this guide.