A Record

A Record ( Address Mapping Record ) is a DNS record which maps a domain name to the IPv4 address of the server which hosts the domain. An A record is used for discovering the IP address of the server connected to Internet from a given hostname. You can associate same hostname with multiple IP addresses by adding another A Record with the same hostname although with a different value of IP address.

How to check an A record

Most DNS tools let you check the A record for your website. In fact, most online tools will first show you the A record for the domain, and next show you the NS records. This checking process is calling a DNS lookup. If you have a UNIX machine you can use the “dig” command to do a DNS lookup.

Editing the A record using Plesk

Plesk has a feature-packed DNS Management tool, here you can change any of your domain records.  Setting the A record you want is simple. To edit the A record, visit the Custom DNS Records page and select the relevant domain. Next, open the drop-down menu and select “A” from the list of records. Type in the IP address that corresponds to the A record you are changing, edit the TTL to meet your requirements and click “Add New” to complete the action.

ccTLD

A Country Code Top-Level Domain (ccTLD) is a two-letter top-level domains (TLDs) dedicated to a particular country to service their community. ccTLDs are based on ISO 3166-1 country codes.

DKIM

DKIM ( DomainKeys Identified Mail ) is a way of checking that the emails you receive haven’t been interfered with en route to you, and that they genuinely do come from the email addresses that they claim to be from. It uses a digitally signed private key that is exchanged between sender and recipient to verify that its bona fide. DKIM helps to protect you from things like spam and phishing attacks—which try to get hold of personal information like your bank account numbers and credit card details.

DNS

Have you ever wondered exactly how your web browser finds the server for a domain name when you enter an address into your web browser? As humans we prefer using memorable domain names like google.com or amazon.com (and there are millions of these). However domain names in text form are not that well suited to computers, network addressing using numerical IP addresses is much more effective.

DNS or the domain name system is the networking tool that matches a domain name to the IP address that corresponds to it. DNS is what helps your web browser find the IP address for the web server that hosts the domain name. In essence, every time you enter a web address into your browser your web server contacts a DNS server to request the IP address for the domain name. By the way, it’s worth noting that every device connected to the internet has an IP address.

Understanding what a DNS server does

It’s easy to compare the way DNS works to a using phone directory: every domain has a matching IP address, just like every name has a matching phone number. In the case of DNS, the IP addresses matching every domain is kept safe and easy to access for anyone. DNS servers, also known as name servers, is what stores these “phone numbers” for IP addresses.

DNS servers are key to a working internet because every time you send a request for a website using a domain name the DNS server first translates the domain name to an IP address and then sends that IP address to your computer, so that your computer can connect to the IP address. Your computer does not directly connect to a domain name.

Whether you visit a website, transfer a file or send an email, it is the DNS server which looks up the IP address for a domain name. Of course, you can avoid generating a DNS query by directly typing the IP address for the website server in your web browser’s address bar. However, it’s not as simple as it sounds because the IP address behind a domain name can change. For big websites you can also find that the website’s domain makes use of multiple IP addresses.

How do DNS servers do their work?

DNS servers co-ordinate two types of internet namespace and name servers save the data for every domain name, including the full DNS records for that domain. It is a very large database and it works smoothly only because there a literally millions of DNS servers which are all interconnected. DNS resolution requests are distributed amongst these millions of DNS servers.

Whenever you access a website or send an email you initiate a DNS lookup request, this involves contacting your local DNS server to see if it knows the IP address of the domain name in question. Your DNS server might have this address, particularly if it is a popular domain name. If it doesn’t it will ask the other DNS server for the information, and yet another, until it finds a DNS server with the information. Your DNS server then returns the IP address to you and also saves it in its local cache in case you want to visit that website again in the future.

DNS Server

You can think of the domain name system ( DNS ) as a platform that powers the internet as we use it every day. That’s because DNS is responsible for converting the domain name you type into the address bar, or the domain behind the “@” in an e-mail address, into the IP address which enables your computer to locate on of the millions of servers that host internet services. But, like any internet service, DNS is merely a concept – unless there is a server behind the service. This is what a DNS server does.

What DNS servers do

Operating in a hierarchy, DNS servers use private network protocols to facilitate communication amongst DNS servers. First, there are master DNS servers each of which contains the full DNS database of all internet domain names – alongside the corresponding IP address. Also known as root servers, these master DNS servers are owned by agencies that operating independently – and which are based in the US, UK, Japan and Sweden.

Lower-level DNS servers, much higher in number, only keep parts of the DNS database and are owned by private companies, either a business or an internet service provider (ISP). DNS servers can basically be any computer which is registered on the DNS system – as long as the server runs the required special software for DNS servers, software that facilitates DNS resolution from domain name to host IP address. Every DNS server has a public IP and also includes a database of the addresses and network names of other hosts on the internet.

How does a DNS server operate?

Typing the address of a website (which will contain a domain name) into the browser address bar starts the communication between the end-user’s PC and the DNS server. The web browser is the DNS client which sends a request for the DNS data to the DNS server that is operated by the end user’s ISP. This server then searches for a matching IP address in its internal DNS database.

Sometimes no match is found. If that’s the case the request is sent to another low-level DNS server, and if necessary, to a root server. Eventually a matching domain name and accompanying IP address will be found, this data is then sent back to the web browser through the DNS network. This DNS lookup process is called forward DNS, which is different from reverse DNS. In reverse DNS the DNS server also takes a major part in the process.

Setting up a DNS server

It’s not difficult to set up a DNS server. All you need is standard server computing equipment, alongside a special set of software which is designed to handle DNS queries. There are a number of solutions, both commercial and open-source, which offers DNS services.

Microsoft DNS

Microsoft’s DNS server used the Microsoft Windows Server operating system and is the 4th ranking product which offers DNS – the first three is the three versions of BIND: BIND4, BIND8 and of course BIND9. Microsoft based their DNS server on BIND4 when it shipped as a test release with Windows NT 4.0, but Microsoft DNS has evolved significantly in the meantime.

Djbdns

While Microsoft’s products are commercial, djbdns is an open-source solution for DNS servers. Interestingly, it was created by just one person – D.J. Bernstein. The view was that it is one of the most secure DNS server options: there is a price of $1,000 if someone finds a security hole in how it works.

Another feature of djbdns is the modular structure it uses. This reduces the amount of code in the main body of the service and as a result reduces the complexity of the associated daemon.

Dnsmasq

Useful for smaller networks, Dnsmasq provides an IP forwarder as well as a DHCP server. It supports both IPv4 and IPv6 while also facilitating conversion from IPv4 to IPv6, and the other way around. Most popular Linux distros include Dnsmasq and there are also ports that can be used for the common BSD releases, including FreeBSD. Linksys ships Dnsmasq with all of its wireless router products.

Domain

If you want to start a website you need two key elements. First, you need a hosting provider which will be the company that stores and provides access to your website. Next, you need a domain name of your own.

Even though most web hosting companies will give you a subdomain such as yourdomain.plesk.com you will still want your own domain name – otherwise your website will always be dependent on the website host that you are using.

An independent website really needs its own domain, so – mydomain.com and not mydomain.plesk.com. A dedicated domain name for your business is a better way to present your company, it’s brand and the products and services you offer.

Understanding domain names

In easy terms, a domain name is an easy way for humans to refer to the IP address that represents the server on which your website is hosted. In other words, a domain name (managed by the domain name service or DNS) is a human readable link to an IP address. However, some domains may have multiple IP addresses associated with them.

A domain name is also indicative of who owns the domain. When you have registered a domain name nobody else can use the domain. Also, when you move your website to a different website host you can keep your domain name, even if the IP address for your website changes.

Domain name services you need to know about

When registering a domain name for your website you need to make sure that the company you register it with provides you with key settings for the domain name. This should include comprehensive management of your DNS settings (including popular DNS records such as A records, CNAMEs, MX and NS records as well as TXT records).

You also need to be able to obtain an EPP key from your registrar and need access to switch the registrar lock on and off. Finally, your registrar should also give you access to WHOIS, the public database for domain name information where your contact information and other domain details such as registrar and registration date is published.

Also note additional domain services which can include domain privacy protection, URL and email forwarding, email sending as well as domain parking. These additional services can be of real value in the long run.

Domain Parking

Sometimes you want to buy a domain to make sure nobody else takes it, but you’re not quite ready yet to use the domain. Or, you have used a domain but the website has been deleted and there’s only a blank or placeholder page in place. Nonetheless, you still want to keep your domain. Domain parking is where you keep a domain safely without actively linking it to a webpage. It’s most common just after people buy a new domain, before they’ve actually started to develop or upload the website that they plan on hosting on the domain.

When a user types in the domain name in the browser bar they will see just a simple page which is not part of your website but which displays a short and temporary message that says it is currently inactive. It may contain some advertising as well, depending on the website host. A parked domain is usually managed by the domain name registrar, and it usually displays a message when visitors go to the domain that says that the domain is empty, or displays an under construction message.

Sometimes a domain registrar will use domains that are parked to display its own advertising messages. Of course, if you don’t want your registrar to display advertising on your domain (without your approval and without you receiving any of the money) you might want to create your own custom parked domain page so that you can control what is displayed on the page, and so that you can make some money from it.

Alternatively, you can configure your domain so that nothing is displayed on it, in other words, it’s just blank. Another option is to partner with a hosting company that offers you the opportunity to park your domain with them and to get a share of the advertising revenue displayed on the parked domain.

Domain Registration

Registering a domain is completely hassle-free nowadays. In fact, when you register a domain the process occurs completely automatically regardless of which domain registrar you use, with a few exceptions. To register your domain you just need to choose a domain which hasn’t been registered by anyone so far. Often you may find that registering the domain with the company which will host your website is the most convenient option as it makes it easier to manage your domain and website all in one place.

Before you register your domain you must make sure you choose the right domain name. Remember, your domain name will represent your business or your hobby for a very long time. Your domain name is very much a brand name in that respect.

Likewise, you need to choose a top level domain (TLD) that matches the goals and the nature of your website. So, if you run an organization or a not-for-profit you might choose a “.org” TLD, whereas a business that actively sells is better represented with a “.com” TLD.

Domain registrars offer different prices and different terms when you register a domain. Before you register your domain, you should do your own research to find a domain registrar that most closely suits your needs.

Registrars can be difficult to deal with, for example choosing the wrong registrar may mean it can be difficult for you to transfer your domain to another domain registrar in the future. Companies can block a domain transfer by refusing to provide an EPP key, or by refusing to unlock your domain when you request an unlock.

Note that in most case you should be able to switch registrars, you can transfer your domain from one company to another company without registering a brand new domain.

Domain Transfer

Sometimes you need to move your domain from one registrar to a different domain registrar. This is called a domain transfer. Ordinarily, it is quite easy to move your domain from one domain registrar to the other, and nothing about your domain needs to change during this process. Note that occasionally a registrar will levy a fee if you want to transfer a domain to another domain registrar.

As the owner of a domain, you are free to transfer your domain to another domain registrar at any time. There is one exception: if you have just registered your domain you must wait 60 days before you can transfer your domain.

Also, be aware the domain transfers are not quick. It can take a few days or in some cases even a few weeks if you want to transfer your domain – and sometimes the company which currently acts as your registrar can try to delay the transfer.

It is important therefore to never try to transfer your domain just before it expires. If you do this you might find that the expiry date is within the transfer period. If that happens you will find it very difficult or even impossible to recover your domain.

The requirements for a successful domain transfer

There a couple of points you need to have in place to make sure that your domain transfer proceeds successfully:

  • You must confirm that you own the domain
  • The domain lock should be set to unlocked before transfer
  • Your domain must have last been transferred no more than 60 days ago
  • The domain must be older than 60 days
  • You need to acquire an EPP Key (also know authorization code) from the company that is currently your domain registrar

Don’t forget, transferring your domain will take a few days and may take even longer than that.

Domain Whois

Domain WHOIS contains information that explains who the owner is of the domain name. It is an international database and a domain WHOIS for every domain is required by the Internet Corporation for Assigned Names and Numbers (ICANN). ICANN is the organisation that co-ordinates the use of IP addresses around the world, as well as the use of TLDs – top level domains.

The information contained in WHOIS data includes the name of the domain registrar, the IP address of the domain alongside the owner’s details – email, phone and physical address. WHOIS also includes the name servers for the domain plus the date on which the domain was registered, and the date on which this registration expires.

There is a reason for making this information public: it enables the easy confirmation of the status for a domain, including the owner behind the domain. It helps put trust in the users of domains, while fighting fraud and helping authorities to perform legal investigations. That said, it could be argued that WHOIS presents a threat to free speech and the anonymity of domain owners.

Note that the term WHOIS can also refer to the communications protocol itself, in other words, the protocol which facilitates the exchange and storage of WHOIS data in the publicly accessible database of WHOIS information.

WHOIS management

Every good domain registrar will offer its customers the ability to manage their WHOIS – it’s called WHOIS management. It allows customers to control specific information that is part of the public WHOIS database. Customers can usually make changes to WHOIS information using their web host’s Control Panel. Any user-friendly hosting control panel will allow unfettered access to domain information and domain settings.

Protecting your domain WHOIS

Domain WHOIS protection is also known as domain privacy protection. It is a service that allows domain owners to hide the real WHOIS data behind their domains. Hiding this data means that the domain owner is protected from a range of threats, including hacking, fraud and spam.

Because WHOIS information is public and accessible to anyone on the internet it is worth thinking about protecting your domain WHOIS information against rogue parties who just need to do a basic WHOIS lookup to find your WHOIS details.