Dns record types explained
A DNS zone is a distinct part of the domain namespace which is delegated to a legal entity—a person, organization or company, who are responsible for maintaining the DNS zone. A DNS zone is also an administrative function, allowing for granular control of DNS components, such as authoritative name servers. This server is called the authoritative name server for the domain.
The authoritative name server then resolves the DNS lookup by providing the IP address, or other data, for the requested hostname.
Each of these levels can be a DNS zone. Acme assumes responsibility for setting up an authoritative DNS server that holds the correct DNS records for the domain. At each hierarchical level of the DNS system, there is a Name Server containing a zone file, which holds the trusted, correct DNS records for that zone.
The root of the DNS system, represented by a dot at the end of the domain name—for example, www. Organizations can run their own DNS name servers, or delegate management to an external provider. If a domain has subdomains, they can be part of the same zone. Alternatively, if a subdomain is an independent website, and requires separate DNS management, it can be defined as its own DNS zone.
The primary server holds the master zone file, and the secondary server constitutes an identical secondary zone ; DNS requests are distributed between primary and secondary servers. A DNS zone transfer occurs when the primary server zone file is copied, in whole or in part, to the secondary DNS server.
A zone file contains mappings between domain names, IP addresses and other resources, organized in the form of resource records RR. To see the actual zone file for a domain, and test DNS zone transfers, you can perform a zone file lookup using one of many DNS tools. A record is made up of the following fields:.
After these two records, the zone file can contain any number of resource records, which can include:. Traditional DNS infrastructure has its limitations. Once upon a time, an IP address pointed to a single server. Now, one IP address can hide a pool of load balanced network resources, deployed on different data centers across the globe. To serve these resources efficiently to users, ensure high performance and allow quick propagation of changes, you should consider a next generation DNS provide like NS1.
What is a DNS Zone? DNS Zones Explained. A record is made up of the following fields: name ttl record class record type record data Name is an alphanumeric identifier of the DNS record. It can be left blank, and inherits its value from the previous record. If not specified, the global TTL value at the top of the zone file is used. Record class indicates the namespace—typically IN, which is the Internet namespace. Record data has one or more information elements, depending on the record type, separated by a white space.
For example an MX record has two elements—a priority and a domain name for an email server. Zone File Tips When adding a record for a hostname, the hostname must end with a period.DNS Records
You can add comments in a zone file by adding a semicolon ; after a resource record. IN SOA ns.
What is a DNS Zone? DNS Zones Explained
NS dns1. NS dns2. MX 10 mx1. MX 10 mx2. A Dedicated DNS - fully managed DNS deployment, on premise or in the cloud, with advanced point-and-click traffic management.
Back to All Resources.The screenshot above is a sample of A Record listings of different types.
Here, the primary naked domain record and blog subdomain point at the same IP address, but are separate records and can be changed individually at any time.
You can see an example of this in the store hostname that points to a cluster of servers of servers that sit behind the thor. Mail Exchanger MX records are used to help route email according the domain owners preference. The MX record itself specifies which server s to attempt to use to deliver mail to when this type of request is made to the domain. The priority number is used to indicate which of the servers listed as MX records it should attempt to use first.
In the screenshot above, you can see that I am using two MX records that have separate priority values and point to different subdomains. These subdomains are pointed at two different email servers that are designated to handle email. If this server is unable to handle the mail request, the next lowest priority number is used, which in this case would be Some email providers have only one MX record and some have well over two. The number of MX entries you will need to create depends largely on the mail provider and how they expect the load on these email servers to be handled.
If you wanted to receive mail on a subdomain, you would adjust the hostname accordingly and ensure your email provider is setup to handle email from the subdomain. A TXT record is used to store any text-based information that can be grabbed when necessary. If you need to verify or provide an SPF record for a specific subdomain, then you will need to use the appropriate hostname in place of the symbol.
The rule of thumb for TXT records is that they require a an attribute name, follow by an equals sign, followed by a value for the attribute. In the same way, places that require domain verification through use of a TXT record will also provide you with a properly formatted TXT record value to use. Although it can be rather easy to understand the record types themselves, knowing about nameservers, registrars, and how a specific set of DNS records gets chosen and used is a little more difficult to navigate, but is just as essential to know.DNS can be quickly updated with some propagation time.
There are a number of DNS Entries you are able to create. For example, you can use it for store. This is a common practice for people who use Amazon, eBay, Tumblr, etc. As an example, an A Record is used to point a logical domain name, such as "google.
These records point traffic from example. They also point localhost. This allows the end user to type in a human-readable domain, while the computer can continue to work with numbers. These records point www. The first record allows the domain to resolve to the same server with or without the www subdomain.
The second record allows you to use an alternative subdomain for email hosting an delivery. The third record allows you to use the docs. This type of record requires additional configuration with Google. A TXT Text record was originally intended for human-readable text. These records are dynamic and can be used for several purposes.
The TXT Value is what the record 'points to', but these records aren't used to direct any traffic. Instead they're used to provide needed information to outside sources. The First record is used for a SPF, Sender Policy Framework, records, those records are used by many email systems to help identify if email is coming from a trusted source, helping filter out spam or messages pretending to be from your domain called spoofing.
An SRV Service record points one domain to another domain name using a specific destination port. Any time DNS is updated, it can take up to 48 hours for those changes to take effect. This period of time is called propagation, and it applies to any and all DNS updates.
This article will explain what propagation is and why it's important. I would like to change my MX Record so I can use a mail server with another provider. Sender Policy Framework records, or SPF records are a type of DNS record used to identify which mail servers should be allowed to send email from a certain domain name. Example: Enabling your domain to use Google's xmpp server is a good example to showcase.
IN SRV 5 0 xmpp-server. Replace this with the subdomain that you want to us, or for the root domain. Host Record: This is the domain or subdomain you wish to use.
The symbol is used to indicate the root domain itself. In our example the Host Record 'ftp' would be for the subdomain ftp. Points to: This is the destination server that the domain or subdomain is sending the traffic to.
The default and lowest accepted value is seconds 4 hours. You do not normally need to modify this value.End-users who browse the internet will rarely encounter DNS terminology in their daily online activity. If you run a website or register your own domain, however, you may suddenly find yourself stepping into a deep and confusing world of technical jargon.
When someone types in a URL such as google. For most web users, this is all they need to know about the basics of DNS. A quick warning before you dive in: changing DNS records will affect how your website is accessed. Read everything below and do more research before making your first changes. The first important piece of information is domain registrars. These entities operate a master list of all the domains registered with their company. When someone buys a URL for their website, they have to go through a registrar.
There are thousands of accredited registrars all across the globe. Many offer web hosting services along with domain registry, so for most intents and purposes, users can consider them one and the same. Domain registrars are where all of the action gets recorded. They usually follow this pattern and come in groups of two or three:. Nameservers are the most time-consuming part of the DNS records process. When you register or change a domain you might see a message stating that the URL may not work for a few hours or even a day or two.
This is because nameservers have to propagate the DNS records to servers across the world before they can recognize a typed website address and translate it to the assigned IP address. Want to see just how far your DNS information has been propagated? One of the first stumbling points for new users is learning to identify zones and records. All of a sudden there are dozens upon dozens of complicated acronyms and indecipherable names.
DNS records are single entries that give instructions on handling received requests. They only provide an initial validation of the information before passing it on to zones. Zones, then, are custom-purposed record systems that handle specific and non-standard requests.
Think of it like a basic filtering system; records gather all the information and sort it to individual zones for processing. There are dozens of types of DNS records and zones.
Each one handles its own type of information to help streamline the DNS processing for maximum speed. You might see some or all of these zones listed in your domain registrar. Records have a few subsections you can manage and edit yourself inside your domain registrar account, at any time. These include altering the record type, switching between zones, changing the subdomain where the record points to, and altering the time to live TTL value.
A record name is the descriptor for your domain entry that effectively creates a subdomain for the record.DNS translates the human-identifiable domain names into physical IP addresses your computer can read.
They are various strings of letters that make the commands for actions the server will follow. Below we will walk through the most common DNS Records. Returns a bit IPv6 address, most commonly used to map hostnames to an IP address of the host.
For example, bare domains like example. Typically, you establish primary and secondary name server records for your domain.
What Are DNS Records? Domain Name System Examples - DNS Zone Editor
Returns only the name because DNS processing is stopped. Points to a canonical name. Start of authority, determines what information in the DNS zone will be used.
This includes information such as, primary name server, the domain serial number, email of the domain administrator and setting a timer for refreshing the zone. TTL, or Time to Live, record sets how much time it will take for changes to go into effect. For example, give something a value and it will take one hour for a change to take affect. Changes made to the TTL value will be constantly checked across the Internet based on the value. These changes will be for subsequent updates and only checked at the interval period you have chosen in the TTL value.
This started originally as random human readable text. This is information you type into your browser to direct it to a specific website, like, www. Skip to content Hostwinds Guides.Takeaway: If you drill into 12 of the most common DNS records, it's a little easier to understand how this system works.
The domain name system DNS is integral to today's internet, and on the surface, it seems extremely complex. It's little wonder that DNS confuses so many people. However, if you get to know some of the most common DNS records — and how they're used — it's easy to get a sense of how this technology works.
Here we'll look at the 12 most common DNS records. In order to associate a domain name with an IP addressit's usually necessary to use A records. These can be in the form of many different host names and subdomains. This is done by declaring a record — such as mail. In this case, "mail," "www" or "ntp" would be the defined A records. These might point at any IPv4 IP address, such as Looking up which IP address is associated with a domain name in this way occurs through a forward DNS lookupor query.
This means that AAAA records are notated using eight groups of bit values, such as: feff:fedcc2a. This eliminates the need for explicitly declaring an IP address and means that the IP address can be changed once rather than twice if a CNAME record simply points at an already established host name, as shown in the following example:.
Here, cname. MX records are those that are looked up by mail servers when email needs to be delivered. They will usually make up more than one mail server for reliability, but this is not always the case, and may be a breach of Request for Comments RFCs. Configured using a simple hierarchy, an administrator can define which mail server should receive mail first and so on.
An example might be as follows, where Priority 5 is the preferred mail delivery host with IP Address 1. Learn from a panel of technologists their predictions for the emerging technologies that will shape the near future. Download now to find out! At the root server level, it's important that there is an authoritative name server configured to respond to queries against a particular domain name. Each domain name should have name server records set up in order to function; using too few name servers may breach RFCs.
The Start of Authority SOA record can show the primary name server for the domain name, the serial number this should be when the last revision was made to the DNS configuration for the zone if it's shown in the correctly specified date formatand other pertinent information relating to how the zone is run by the administrator.
Also shown inside the SOA record is an email address of whom to contact, or the responsible person RPin the event of a misconfiguration or some other issue relating to the DNS zone.
Within the SOA, it's important to announce how other machines should react when communicating with the authoritative name servers for a DNS zone. Such an example might be:. Here we see the domain name for techopedia.
DNS Records Explained: What Is The Domain Name System?
Finally, we can see its serial number suggesting in this case that salient changes haven't been made sincefollowed by a number of time to live TTL values that control how long data received from a name server might be trusted before being considered stale, among other things. With the ever problematic unsolicited mail issue on the internet, one common method of combating it was to use DNS to declare which outbound mail servers were allowed to send mail from a domain name.
Google's site verification system has obviously needed a way to identify that a particular domain name or host name belongs to an administrator during a configuration process request. In this case, it has asked for DNS entries to be created to authenticate that request. Google most likely assumes that only the owner of the domain name will have access to the name servers responsible for running the domain name and therefore, only they will be able to make DNS changes to the domain name.
In order to provide data for reverse DNS lookups where an IP address is converted into a domain name, instead of the other way round IPv4 uses in-addr.
Separate from the root servers running the delegated forward DNS for domain names, the reverse DNS is configured by five regional internet registries RIRseach of which is responsible for a certain geographic region.
Notice that the notation is reversed:. Even among seasoned technical staff, the fact that reverse DNS is delegated by RIRs is sometimes overlooked and missed during troubleshooting.It also contains pseudo-RRs. The "type" field is also used in the protocol for various operations. Progress has rendered some of the originally defined record-types obsolete.
Of the records listed at IANA, some have limited use, for various reasons. Some are marked obsolete in the list, some are for very obscure services, some are for older versions of services, and some have special notes saying they are "not right". From Wikipedia, the free encyclopedia. The Internet Society. October Internet Engineering Task Force. May Retrieved 17 October Internet Assigned Numbers Authority. September Retrieved 9 March July Retrieved 14 March RFC Retrieved August 31, April Retrieved 26 April Hidden categories: Pages using RFC magic links.
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