DNS Terminology

Understanding DNS Terms

It's time to take the mystery out of DNS. First, here's what it means: Domain Name System (DNS). However, to understand the world that surrounds DNS, it's important to recognize the supporting vocabulary. DNS Made Easy put together a list of important terms with definitions. This terminology will help kick start a foundation in DNS.

DNS Book

A records are address records which map a host name in a domain to an IP address. For example, www may be the name field of an A record within the example.com domain. This enables www.example.com to point to the IP address of a web server which hosts the content for example.com. The root record of a domain name (sometimes referred to as @) can also be an A record, this is an A record with a blank name field.

Learn how to Create, Modify and Delete an A Record

AAAA records map a FQDN (fully qualified domain name) to an IPv6 address, the IPv6 equivalent to an A record.

Learn how to add an AAAA record.

ANAME records are a proprietary record type created by DNS Made Easy to bypass limitations in the DNS RFC's. They are alias records that allow you to map the apex (root record) of a domain to a target FQDN. When an ANAME record is created, DNS Made Easy resolves the target FQDN to an IP address or set of IP addresses which the host name of the ANAME record then resolve to.

Learn how to create an ANAME record.

Authoritative DNS servers store the canonical mapping of URL to IP for the domains under their control. They are the source of the information that the recursive DNS servers send to web clients like browsers. Authoritative DNS servers for a website are usually provided by web hosting companies or specialist DNS hosting companies.

For example, If I have a a DNS server in my network that holds an A record for example.com, my DNS server would be authoritative for the example.com domain. If clients needed to access example.com, they could query my DNS server and they would get an authoritative response. Learn about recursive name servers.

An AXFR is a type of DNS zone transfer. It is a mechanism for replicating DNS data across DNS servers. This is the most efficient method for importing domains into the DNS Made Easy system. You can import your zone information using AXFR transfer as long as your current provider supports this method of transfer.

Learn how to Import Records from a Name Server using AXFR.

DNS caching is the method by which any DNS server or client locally stores recently queried DNS records to re-use them in the future eliminating the need for new DNS queries and improving the efficiency of DNS.

The Domain Name System implements a time-to-live (TTL) on every DNS record. The TTL specifies the number of seconds the record can be cached by a DNS client or server. When the record is stored in cache, whatever TTL value came with it gets stored as well. The server continues to update the TTL of the record stored in the cache, counting down every second. When it hits zero, the record is deleted or purged from the cache. At that point, if a query for that record is received, the DNS server has to start the resolution process again.

A content delivery network or content distribution network (CDN) is a server which allows for faster, more efficient delivery of media files. It does this by maintaining copies of media at different points of presence (POPs) along a global network to ensure quick client access and the fastest delivery possible. Querying clients access the closest content server eliminating long wait periods while photos or videos are downloaded. CDNs serve a large fraction of the Internet content today, including web objects (text, graphics and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social networks.

CNAME records are referred to as alias records as they point a host name to another host name or FQDN. CNAME records are used to point multiple hosts to a single location without specifically assigning an A record to each host name. CNAME records can also be used to point a host name to a location external to the domain. To resolve a CNAME record, the name server must behave slightly differently than it would with a normal query of another record type. When a name server looks up a name and finds it is a CNAME record, it replaces the name with the canonical name (the target of the CNAME) and looks up the new name, in a sense performing two queries to reach the final resolution.

Data centers are physical or virtual infrastructure used by enterprises to house computer, server and networking systems and components for the company's information technology (IT) needs, which typically involve storing, processing and serving large amounts of mission-critical data to clients in a client/server architecture.

A data center, or datacenter, often requires extensive redundant or backup power supply systems, cooling systems, redundant networking connections and policy-based security systems for running the enterprise's core applications.

The delegated name servers represent the name servers currently assigned to your domain at the registrar. Through this name server assignment the registrar registers your authoritative name servers with the TLD registry.

When the authoritative name server for a domain receives a request for a subdomain's records and responds with NS (Name Server) records for other name servers, that is DNS delegation of a subdomain. Essentially, it is passing on authority for this subdomain to another collection of name servers.

DomainKeys Identified Mail (DKIM) records allow a recipient to validate a sender as the owner of an email message. Domain Keys use public key encryption to apply digital signatures to email, this allows verification of the sender as well as of the integrity of the message in question. DK/DKIM records are generated by your email service provider and created as TXT Records within DNS Made Easy. Visit the Domain Key public website to learn more at dkim.org.

The resolver or resolving name server is responsible for performing the DNS resolution process (DNS request-and-response process).

  1. It receives the request for a name resolution from an application.
  2. Formats the request in the correct manner for the server to process.
  3. It sends the request to the name server, which is responsible for returning the response to the resolver.
  4. The resolver formats the response from the name server in a way that's appropriate for the application, and return the formatted response to the application.

The Domain Name System (DNS) converts domain names we type in our web browser address bar (www.google.com) to Internet Protocol (IP) addresses (173.194.39.78). This is necessary because, although domain names are easy for people to remember, computers or machines, access websites based on IP addresses.

DNS is often compared to a phone book of the internet. DNS matches human-readable names to numbers that machines can more easily understand.

Check out our infographic: DNS Explained Visually.

The DNS server provides answers to DNS queries of domains, that it is authoritative for, which it receives from DNS clients.

The DNS Client is the client component that resolves and caches Domain Name System (DNS) domain names. When the DNS Client service receives a request to resolve a DNS name that it does not contain in its cache, it queries an assigned DNS server for an IP address for the name.

When a DNS client requires resolution of a host name to an IP address, it requests this resolution from a DNS server. This process is referred to as a DNS query. Each query the client sends contains three pieces of information, specifying a question for the server to answer:

A specified domain name, stated as a fully qualified domain name (FQDN).

A specified query type, which can either specify a resource record by type or a specialized type of query operation.

A specified class for the DNS domain name.

DNS queries can be classified according to the manner in which a complete request is processed. Generally queries can be classified as follows.

  1. Recursive query: When a DNS client sends a recursive query to a local name server, that local name server must return the IP address for the FQDN entered, indicate that it can't find an address, or return an error saying that the requested address does not exist. Name servers do not refer the client system requesting a recursive query to other DNS servers. When answering recursive queries, the originating client does not receive address information directly from any DNS server other than the local name server.
  2. Iterative query OR Non-recursive query: In iterative queries, name servers return any information they have related to the FQDN, be it an answer or referral to another name server. Although a DNS server may not know the IP address for a given FQDN, it might know the IP address of another name server likely to have the IP address being sought, so it sends that information back. The response to an iterative query can be likened to a DNS server saying, "I don't have the IP address you seek, but the name server at 10.1.2.3 can tell you". An important thing to note is that, all DNS server's must support iterative (non-recursive) queries.
  3. Inverse queries: When a DNS server receives an inverse query, it returns the FQDN for an IP address, rather than an IP address for a FQDN. However, searching the entire Internet for aFQDN match would prove time consuming. Rather than waste resources, use of the "in-addr.arpa" domain notifies name servers of an inverse query. Another name for this type of DNS query is a Reverse DNS query.

A DNS zone is any portion of the domain name space in DNS for which administrative responsibility has been delegated to a single manager, typically a collection of name servers. The DNS zone contains all resource records contained in the domain name for resolution of that domains name space. The DNS zone in text based form is called a zone file.

A DNS record, also referred to as a resource record is an entry in a DNS zone file that points a specific host within a domain to a specified resource or service. DNS resource records have different types for different associated services including but not limited to NS, A, AAAA, CNAME, MX, SOA, SPF, PTR, SRV, TXT, or DK/DKIM records.

Domain name system security extensions (DNSSEC) are a set of protocols that add a layer of security to the domain name system (DNS) lookup and exchange processes. While DNSSEC cannot protect how data is distributed or who can access it, the extensions can authenticate the origin of data sent from a DNS server, verify the integrity of data, and authenticate nonexistent DNS data.

DDoS attacks (distributed-denial-of-service attack) consist of disrupting or abolishing services of a host connected to the Internet. Typically DDoS attacks are carried out through some means of flooding a system with valid or invalid traffic rendering it unavailable to other clients attempting to access its resources. The perpetrators behind DDoS attacks usually go after large, well-known web servers, targeting banks, governmental sites, and root name servers. DDoS attacks are vicious, unrelenting, and they can hurt businesses of any size.

Learn how to mitigate a DDoS attack.

Check out our infographic on DDoS - Arm Yourself with Knowledge.

An endpoint represents a network resource by host name, such as a FQDN, or by IP address and port number of associated with a service.

DNS Failover is used to keep sites and web services online in the event of system or network issues. This is done by automatically moving DNS traffic of a specific host to another IP address. This service can also be used to migrate traffic between redundant internet connections. Typically DNS Failover services are implemented through the configuration of monitoring servers which continuously check a target primary IP address on a specific port and protocol. As soon as the monitoring servers detect the primary IP address as unavailable on this monitored criteria, traffic is migrated to the defined secondary IP address.

A forward DNS lookup resolves an internet domain name (FQDN) to an IP address. A reverse DNS lookup resolves an IP address to an internet domain name (FQDN).

A fully qualified domain name consists of a host, a second-level domain, and a top-level domain. For example, www.dnsmadeeasy.com is a fully qualified domain name where www is the host, dnsmadeeasy is the second-level domain, and .com is the top-level domain.

What is the difference between a hostname and a fully qualified domain name?

The host name is the name of a specific system in a network. The FQDN is the host name of the specific system in the network in addition to the domain name and associated TLD. So if the name of a system in the DNS Made Easy network is "workstation1" and this system exists in the subdomain of sales.dnsmadeeasy.com, the FQDN of this system is workstation1.sales.dnsmadeeasy.com.

The global traffic director service is a geographical (geo-DNS) source-based IP routing methodology. This unique type of service allows an administrator to optimize and direct DNS traffic based on the geographical location of the querying client. The result is that querying clients from different regions of the world can receive different query responses.

By regionally dividing traffic among different servers or data centers, an administrator can easily increase the performance of a web application or services. When clients are able to access websites and services with greater speed, they are provided a higher level of service which directly relates to higher revenue, higher productivity, and a competitive advantage.

Learn how DNS Made Easy's Global Traffic Director works.

Global load balancing is a method used to spread web traffic to multiple servers based on a regional location. From the querying clients perspective, the web browser performs a DNS lookup for the FQDN being requested, connects to the IP address(es) of the closest server location determined by the AS path, and if multiple IP's are defined for a specific region splits traffic evenly between those hosts. Splitting the traffic using round robin at a regional level provides the highest level of performance and the best experience for the end client.

Used in conjunction with DNS Failover services in a matter of milliseconds, DNS Made Easy's monitoring nodes assess the health servers based on a monitored port and protocol, and send traffic only to IP addresses determined as "up" using DNS Made Easy's instant IP updates and Global Traffic Director (GTD) service which can route traffic to the proper regional system.

A generic top-level domain (gTLD) is one of the categories of top-level domains (TLDs) maintained by the Internet Assigned Numbers Authority (IANA) for use in the Domain Name System of the Internet. It is visible to Internet users as the suffix at the end of a domain name.

Examples of of well-known gTLDs are com, org, info, net, and biz. Generic and restricted TLDs created during the early DNS days require proof of eligibility for domain name registration. These TLDs are gov, mil, int and edu.

In 2012 ICANN implemented a gTLD expansion program, which launched many new gTLDs. New TLDs, like "ninja" and "unicorn," are examples.

HTTP Redirection Records are special records in that they are a combination of an A record and the use of an application server which looks up the destination URL of the A record in a database. This allows administrators to define a DNS record that maps a host name to a URL.

Learn more about HTTP Redirection including Examples.

http redirection

An IP address is assigned to every computer on an Ethernet network. Like the street address for your home, an IP address identifies network computers. It helps traffic flow between computers because each one has its own IP address. No two computers on the network can have the same IP address.

IP is often prefixed by the acronym TCP, as in TCP/IP. The TCP part stands for Transfer Control Protocol: It’s simply a set of rules for transmitting information on a network. Technically, TCP/IP refers to the methods and engineering as opposed to a specific address or value.

There are two standards for IP addresses: IP Version 4 (IPv4) and IP Version 6 (IPv6). All computers with IP addresses have an IPv4 address, and many are starting to use the new IPv6 address system as well. Here's what these two address types mean:

  • IPv4 uses 32 binary bits to create a single unique address on the network. An IPv4 address is expressed by four numbers separated by dots. Each value ranges from 0 through 255. For example: 216.27.61.137
  • IPv6 uses 128 binary bits to create a single unique address on the network. An IPv6 address is expressed by eight groups of hexadecimal (base-16) numbers separated by colons, as in 2001:cdba:0000:0000:0000:0000:3257:9652. Groups of numbers that contain all zeros are often omitted to save space, leaving a colon separator to mark the gap (as in 2001:cdba::3257:9652).

An ISP (Internet Service Provider) is a company that collects a monthly or yearly fee in exchange for providing the subscriber with Internet access. Methods of Internet access include dial-up service, cable, DSL, and more. While some ISPs are local, only serving subscribers in a limited geographical region, others provide service nationally.

When looking for an ISP, consumers will usually start by considering the type of Internet access desired. Some companies only offer dial-up access, which is the slowest — but cheapest — type of connection. Consumers who want cable service will want to check with their local cable TV provider to see if cable access is offered. For DSL service, individuals may have multiple choices, although DSL is not available in all locations. Customers can often call the phone company to ask about service availability or the plans to upgrade local telephone lines.

The goal of DNS is to resolve a fully qualified domain name (FQDN) to an IP address. This work can either be done by the DNS server or the DNS client. These approaches are referred to as Recursive or Iterative, respectively.

Lets go through the steps involved.

STEP 1: You enter www.example.com in the browser. So the operating system's resolver will send a DNS query for the A record to the DNS server 172.16.200.30.

STEP 2: The DNS server 172.16.200.30 on receiving the query, will look through its tables(cache) to find the IP address(A record) for the domain www.example.com. But it does not have the entry.

STEP 3: Now instead of querying the root server's, our DNS server will reply us back with a referral to root servers. Now our operating system resolver, will query the root servers for the answer.

Now the rest of the steps are all the same. The only difference in iterative query is that...

  • if the DNS server does not have the answer, it will not query any other server for the answer, but rather it will reply with the referral to DNS root server's
  • But if the DNS server has the answer, it will give back the answer(which is same in both iterative and recursive queries)
  • In an iterative query, the job of finding the answer(from the given referral), lies to the local operating system resolver.

It can be clearly noted from the above figure, that in an iterative query, a DNS server queried will never go and fetch the answer for you(but will give you the answer if it already has the answer). But will give your resolver a referral to other DNS server's(root server in our case).

Latency is the length of a delay that end users experience when trying to access content. Latency is the #1 “Key Performance Indicator” (KPI) for a DNS system’s success.

MX records are mail exchange records used for determining the priority of email servers for a domain. The lowest priority email server is the first destination for email. If the lowest priority email server is unavailable, mail will be sent to the higher priority email servers.

Learn how to set-up an MX Record.

A name server is a specialized server on the Internet that handles queries or questions from your local computer, enabling you to enter www.example.com instead of 66.249.64.0. It is managed by a web host that is specifically designated for managing the domain names that are associated with all of the hosting provider's accounts.

Every web site has two name servers to which it is pointed, and this process must be done by the webmaster upon purchasing a domain and a hosting account. If you have more questions about domain name pointing and your web hosting name servers, it is recommended that you contact your web hosting provider.

What do DNS requests to name servers look like?

When you type example.com into the address bar, your computer then uses DNS to retrieve the current name servers for example.com.

The public nameservers; ns1.example.com and ns2.example.com are retrieved.

Your computer asks the name servers for the A (address) record for example.com.

The public nameservers respond back with the IP address 92.123.45.0.

The computer sends a request to that IP address along with the page you're requesting.

The web server hosting example.com then sends your web-browser the requested page.

Now if you wanted to, you could bookmark or copy down http://92.123.45.0 for anytime you'd like to come back to the website. More than likely though, example.com is going to be much easier for you to remember, and this is why nameservers exist on the Internet.

A name which DNS usually converts in to an IP, such as www.google.com. It is the part of a domain between the dots.

Name server (NS) records indicate which name servers are authoritative for a domain. In most cases NS Records are used in the event that another external DNS provider will be used in conjunction with DNS Made Easy DNS or if a sub domain delegation will take place to external name servers.

Learn how to work with NS Records.

PoP is primarily the infrastructure that allows remote users to connect to the Internet. A PoP is generally present at an Internet service provider (ISP) or the telecommunication service provider. It can consist of a router, switches, servers and other data communication devices. An ISP or telecom provider might maintain more than one POP at different locations, with each catering to a distinct user base.

DNS Made Easy has 14 PoP's. Check out our Network Implementation.

The Domain Name System, or DNS, is a computer database that resolves alpha URL addresses into its numeric equivalent, also known as the IP address. When a computer connects to the Internet, it is assigned a primary DNS and a secondary DNS server address to make administration easier and provide more security than just a single server. Once zone data has been created for a primary server, it does not need to be copied over to the secondary server because the two servers automatically share zone data.

A primary name server is the read/write copy of the DNS database. The primary server is also responsible for communicating with the secondary server. This means that whenever a new DNS record is added to the DNS database either automatically by the DNS clients or manually by the administrators, it is actually written in the primary zone of the DNS server. One DNS server can have only one primary DNS zone.

Since the primary zone of the DNS server is the read/write copy of the DNS database, it must be kept at a location where it remains physically protected from attacks, and remains safe from internal or external network threats and intrusions.

The process of a primary web server communicating with the secondary server is known as a zone transfer, as zone data is being sent from a DNS server to another.

A PTR Record is also called a reverse DNS record. A PTR record associates (or resolves) an IP address to its associated hostname. This is the exact opposite of the process of resolving a hostname to an IP address. For example, when you look up example.com it will get resolved to the ip address using the DNS to something like 192.168.1.5. Reverse PTR record does the opposite; it looks up the hostname for the given IP address. In the example above the PTR record for IP address 192.168.1.5 will get resolved to example.com.

Creating a PTR record will help your mail server pass some security tests when connecting to other mail servers. It lets the receiver of your emails check for possible spoof emails which will be treated as spam. Without this record, the receiver must rely on guessing if your email might be spam. Generally, when you have a PTR record, your emails have a better chance to deliver to the recipient's inbox instead of the spam folder.

Learn how to setup a PTR Record.

QPS is a common measure of the amount of search traffic an information retrieval system, such as a search engine or a database, receives during one second. This measurement is important in assessing how support infrastructures handle changing amounts of Web traffic and whether systems are scalable enough to serve the changing needs of a user community as they grow.

When you visit a website on the Internet, the computer you use will find the address of the site using a system called DNS. If you are using your home computer to browse the internet, it will request each website address from your Internet Service Provider (ISP). There are two types of DNS queries that can be made to your server: Recursive and Iterative Queries.

With Recursive requests, your server will attempt to find the website in question in its local cache. If it cannot find an answer it will query other DNS servers on your behalf until it finds the address. It will then respond to the original request with the results from each server's query.

With Iterative requests, the DNS server will attempt to find the website in question in its local cache. If it cannot find an answer it will not ask other DNS servers but will reply back to the original request with a single "I don't know, but you could try asking this server" message.

If your server doesn't enable recursive DNS lookups, it will simply treat any such requests as an iterative DNS inquiry.

When you visit a website on the Internet, the computer you use will find the address of the site using a system called DNS. If you are using your home computer to browse the internet, it will request each website address from your Internet Service Provider (ISP). There are two types of DNS queries that can be made to your server: Recursive and Iterative Queries.

With Recursive requests, your server will attempt to find the website in question in its local cache. If it cannot find an answer it will query other DNS servers on your behalf until it finds the address. It will then respond to the original request with the results from each server's query.

With Iterative requests, the DNS server will attempt to find the website in question in its local cache. If it cannot find an answer it will not ask other DNS servers but will reply back to the original request with a single "I don't know, but you could try asking this server" message.

If your server doesn't enable recursive DNS lookups, it will simply treat any such requests as an iterative DNS inquiry.

Root name servers are the servers at the root of the Domain Name System (DNS) hierarchy.

DNS server software do not make it mandatory to include the last . in an FQDN (Fully Qualified Domain Name). For example, www.example.com. So the translating computer will begin its job from right to left, with dot com example www. The first dot, indicates root servers.

DNS root servers are the most critical component for a successful working of internet. This is majorly due to following reasons.

  • DNS root server's are the first step in resolving any domain name.
  • If something happens to them at large, the whole of internet will be affected

There are 13 designated DNS root servers for IPv4. They are mentioned below.

Root Server Name Managed By
a.root-servers.net VeriSign, Inc.
j.root-servers.net VeriSign, Inc.
b.root-servers.net University of Southern California
c.root-servers.net Cogent Communications
d.root-servers.net University of Maryland
e.root-servers.net NASA
f.root-servers.net Internet Systems Consortium, Inc.
g.root-servers.net US Department of Defence
h.root-servers.net US Army
i.root-servers.net Netnod
k.root-servers.net RIPE NCC
l.root-servers.net ICANN
m.root-servers.net WIDE

Round robin DNS is nothing but a simple technique of load balancing various Internet services such as Web server, e-mail server by creating multiple DNS A records with the same name. If you find yourself in a situation where one server isn't cutting it anymore and you would like to easily distribute load across several servers with identical configuration answering to the same backend, one way to accomplish it is to use round-robin DNS. Round robin allows you to map a domain name to multiple IP addresses. Accompanying the round robin DNS strategy is "failover monitoring" which observes a web server or servers to pick out which IP address is functional.

When a DNS request arrives at a round robin DNS server, it responds by returning IP addresses in rotation. For example, if a Web site is made up of 10 servers with the same set of Web pages and content, the IP address of the first server is delivered to the first request; then the second address in the list is given to the second request and so on. This is a continuous loop. When the 11th request comes in, the first IP address is once again handed out; the 12th request, the second address, etc.

Learn how to configure DNS Round Robin

Secondary servers can be used to offload DNS query traffic in areas of the network where a zone is heavily queried. In addition, if a primary server is unavailable, a secondary server can provide some name resolution in the zone until the primary server is available.

Because a primary server always maintains the master copy of updates and changes to the zone, a secondary server relies on DNS zone transfer mechanisms to obtain its information and keep the information current. Issues such as zone transfer methods — using either full or incremental zone transfers — are more applicable when you use secondary servers.

Learn how to setup Secondary DNS

Sender Policy Framework (SPF) Records are used for email validation to mitigate spam. SPF records allow domain administrators to define all hosts allowed to send mail for a domain by creating a specific TXT record that is then used by mail exchangers to validate a senders identity. The original specifications for SPF required storage of SPF information for domains within TXT type records. Later specifications created the SPF type record and then subsequently redacted that reverting back to TXT records for SPF configurations. Currently, there are no SPF implementations that will not use TXT type records if they are present, so SPF type records are not required. There are, however, some SPF implementations that will not use SPF type records, so TXT records remain required. It is a good idea to have identical SPF information within a domain under both a TXT type record and an SPF type record.

Learn how to Configure a SPF Record.

An SOA(Start of Authority) Record is the most essential part of a Zone file. The SOA record is a way for the Domain Administrator to give out simple information about the domain, including the primary name server, the email of the domain administrator, the domain serial number, information on how often it is updated, when it was last updated, when to check back for more info and so on. A Zone file can contain only one SOA Record.

A properly optimized and updated SOA record can reduce bandwidth between nameservers, increase the speed of website access and ensure the site is alive even when the primary DNS server is down.

Learn how to create and customize your own SoA record.

Often confused with a record, a subdomain is technically defined as when you assign a different section of name servers for part of a domain. For instance "dnsmadeeeasy.com." is a subdomain for "com.". Creating "sub.dnsmadeeasy.com." on a different group of name servers than "dnsmadeeasy.com." would be creation of a subdomain. You would create a subdomain for "sub.dnsmadeeasy.com." rather than a record if for example, "sub.dnsmadeeasy.com." will be assigned to different name servers than "dnsmadeeasy.com."

Learn how to Create and Delegate a Subdomain from your Managed DNS Domain.

In the DNS Made Easy system the System NS Records represent the DNS Made Easy name servers which are assigned to your domain when it is created in DNS Made Easy. These are the name servers the registrar would be told to assign to the domain in the event the DNS services are moved to DNS Made Easy.

The TTL is a value in a DNS record that determines the number of seconds before subsequent changes to the record go into effect. Each of your domain's DNS records, such as an MX record, CNAME record, and so on, has a TTL value. A record's current TTL determines how long it will take any change you make now to go into effect. Changes to a record that has a TTL of 86400 seconds, for example, will take up to 24 hours to go into effect.

Setting a TTL value of 3600 will tell servers across the Internet to check every hour for updates to the record. The shorter TTL will only take effect after the prior period expires. This means that next time you update the record, your change will take up to one hour to go into effect. To make subsequent changes happen even more quickly—for example, if you think you might want to quickly revert a change, you can set a shorter TTL, such as 300 seconds (5 minutes). Once the records are configured correctly, setting a TTL value of 86400, tells servers across the Internet to check every 24 hours for updates to the record.

Learn how to configure a bulk change TTL

A TXT record is an abbreviation for text record and is a type of resource record in the Domain Name System (DNS) used to provide needed information to outside sources.

These records hold free form text of any type. A fully qualified domain name may have many TXT records. The most common uses for TXT records are Sender Policy Framework (SPF), DomainKeys (DK), and DomainKeys Identified E-mail (DKIM). TXT records historically have also been used to contain human readable information about a server, network, data center, and other accounting information.

Learn how to Enter an SPF Record as a TXT Record.

Unicast transmission, in which a packet is sent from a single source to a specified destination, is still the predominant form of transmission on LANs and within the Internet. All LANs (e.g. Ethernet) and IP networks support the unicast transfer mode, and most users are familiar with the standard unicast applications (e.g. http, smtp, ftp and telnet) which employ the TCP transport protocol.

Before you choose a DNS service provider, find out about their uptime and downtime. Ideally, you should settle for nothing less than 99% uptime and 99.9% is what you should shoot for critical services. Apart from uptime, you want to check whether the provider offers backup services for redundancy. Some hosts provide backup as add-on feature while others offer it as part of their primary package.

DNS Made Easy guarantees 100% Uptime: Like your sites to stay online? So do we. A 99.9999% overall uptime history is something that very few providers worldwide can claim and DNS Made Easy was one of the first DNS providers to offer a 500% SLA for all DNS services. As always, we are raising the standard for DNS services and the market as whole.

Vanity DNS is an optional configuration that allows you to rebrand DNS Made Easy name servers using your own domain name. The end result is that your own domain name becomes the host name for your name servers which map back to IP addresses of DNS Made Easy name servers.

Why use vanity name servers?

When you do a Whois lookup on your domain, or if you use our domain routing tool, anyone can see the name servers that your domain name points to. For instance if your domain was example.com here is what you'd see:

Before vanity name servers:

NS1.DNSMADEEASY.COM
NS2.DNSMADEEASY.COM

After vanity name servers:

NS1.EXAMPLE.COM
NS2.EXAMPLE.COM

Learn how to configure Vanity Name Servers in your DNS Made Easy account.

Wildcard Records give administrators the ability to map all (or a section) of the records in your domain to one IP. This is a record with a * that will resolve queries for any name space not explicitly defined by other DNS record types in your domain.

Learn how to set up a Wildcard Record.