An A record is a type of DNS record that maps a name to an IP address. For example, the A record for serverfault.com is 64.34.119.12

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CNAME and A record have different TTLs. Which one will be cached?

If a CNAME has a TTL of 1 hour that points to an A record with a TTL of 1 minute, will someone who looks up this CNAME have the entire result cached for 1 hour, or will it will keep having to lookup ...
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A Record VS. Cname Round N

Experienced DNS Admins please help me understand... I run a small DNS server in a development environment that runs resolution for at most 5 domain names at any one time. My question stems from a ...
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www a-record vs cname-record

I have a website that I will be hosting the DNS for (testing purposes at first and then it will have some limited traffic). I have set up DNS so that site.tld has an A record to the actual IP, but I ...
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Why are Amazon EC2 Elastic IPs encouraged to be used with a CNAME rather than an “A” record?

I am setting up a server on EC2 that will be used by people that will be freaked out when they see ec2-111-111-111-111.compute-1.amazonaws.com in the URL bar. I know this would be solved by using an ...
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Wildcard 'A' record overriding CNAME record

I have a Wildcard * A record for self-registration of subdomains by users on our web app. All works fine. I now need to set up an alias for support.mydomain.com to point to mydomain.freshdesk.com. ...
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DNS NS Records vs A Record

I wish to have someone point and resolve their domain to my web server to begin serving their pages. Is it enough to have the person set only the NS1 and NS2 records to my name server, or must they ...
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should Apex domains (and records) be avoided?

I'm building an app that is hosted on Heroku. Heroku suggests that Apex Domains are a Very Bad Idea -- they suggest using CNAME records and a workaround service like Zerigo or DNSSimple. However, ...
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Best practice for placing DNS records and subdomains

Say I have mydomain.com: Is it better to use option A: [A] mydomain.com 123.45.67.89 [A] www.mydomain.com 123.45.67.89 or option B: [A] mydomain.com 123.45.67.89 [CNAME] ...
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Is setting an empty/blank DNS A record allowed?

I'm trying to wrap my head around the wonderful world on DNS. I have created a zone file for example.com which contains: @ A 1.2.3.4 * A 1.2.3.4 However I am also setting up my local ...
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A-Record Failover?

I have a Fortigate 100D with 2x BT Business Infinity Fibre connections acting as WAN1 & WAN2. The BT lines come with 5 static public IPs each and I have my DNS hosted through CloudFlare pointing ...
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How would you setup a up an A record for any negative query?

How would I go about setting up an A record for in Bind9 for any negative queries? I want to forward our staff to an informational page if they were to visit a non existent domain. We have an internal ...
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Do CNAME records overrule A records?

I have several A records like so: Subdomain IP Address example.example.com 198.51.100.0 example.com 203.0.113.0 And a CNAME record that looks like this: Alias ...
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Redirect subdomain.example.org to somethingelse.com hidden to the user?

I'm not knowledgeable at all about C-NAMES, A-RECORDS, name servers and the like, so just bear with me on this one: I want to redirect subdomain.example.org to another domain somethingelse.com. I do ...
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1answer
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A record required for MX record?

Previously our domain, let's call it ourdomain.com, pointed to an IP address (our web host). In addition, we use Office 365 to handle our domain email accounts. DNS records: ourdomain.com A ...
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CNAME versus an additional A&AAAA record

So, let us say that we have set-up an A record and an AAAA record for @, and for www we have set-up a CNAME pointing to @. When a new visitor visits example.com and the webserver sends a 301 ...
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Is a subdomain with both A records and NS records valid?

Let's say I own example.com. I then create an A record on test.example.com to 1.1.1.1. I then create a NS record on test.example.com to ns1.anotherdnshost.com. At another DNS host, I add an A ...
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Is @ the same as the IP address for @ in the MX record entry of a zone file?

I have the following configuration in my DNS Zone. I want to switch the @ record to a different IP address, but I want to keep the MX records the same. Please note the IP address has been changed to ...
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Windows Server 2008 - Zone Scavenging - “This zone can be scavenged after”

I have set up DNS scavenging on our Windows Server 08 R2 boxes as we had records in there that were duplicated and some dating back to 2004! I set the no-refresh and refresh-after intervals both to 3 ...
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What happens when I change a Name Server record or an A record in the Zone file or the DNS settings?

I don't really understand how the internet and DNS works. I am inundated with terms I don't understand when trying to read about it on wikipedia. I don't have a computer science background. When ...
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Multiple DNS records pointing to a single domain

Our business currently subscribes to a DSL internet connection. We're moving away from this and in fact will have two 3Mbps dedicated fiber connections run into our operations center in the coming ...
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Best CNAME TTL strategy for fallover switching

I've recently been thinking about the TTL of our DNS. We have A records for our servers and then CNAME records for the customer facing names. The www CNAME points to server-01 for example. In the ...
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Disable AAAA lookups in libcurl

We have a step during in of our large map reduce that does DNS resolutions. The application itself uses the c-ares library as well as libcurl. I notice that with each resolution, there is first an ...
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How do large SaaS providers support A records? [closed]

According to RFC 1035 CNAME records cannot be used used in a zone apex because a CNAME record cannot exist alongside records such as SOA. This is frequently a source of frustration for those trying ...
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Is Downtime Needed after changing the Ip Address of A Subdomain?

I have a subdomain whose DNS A Record I would like to change. After doing this, do I have to wait for some time before the change will be reflected? If yes, during the downtime is it possible to put ...
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Using www.example.com as the A record

I want example.com and *.example.com to always resolve to www.example.com So if I set the DNS records as: www A server ip (root) CNAME www.example.com * CNAME ...
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Website doesn't work when missing “www”

Does anyone know the solution to this problem? I checked my zone file and there are 2 A records mydomainname.com. 14400 IN A ip.address.x.x localhost 14400 IN A ...
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CNAME, A, and Apache - Why does one work and not the other?

I have a website, example.tld. The DNS has an A record for example.tld that points to 1.2.3.4. Is there any difference (as far as Apache is concerned/configured) whether a sub-domain ...
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1answer
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How to set up a BIND DNS server to respond a single IP address to any request on Windows?

I want to configure a BIND DNS server (since Windows Web Server 2008 does not have DNS service, I had to install BIND) that responds any request with a single A record. I had set up a * record but it ...
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Registrar and Host are Different - Should I move DNS?

Registrar and Host are different companies. Obviously A, MX, CNAME, TXT, SRV should be changed. However, should I move Domain Name Servers to the Host or keep them with the Registrar? Thanks.
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Avoiding downtime while switching CNAMEs with AWS's Route53

I'm trying to make a seamless transition from Heroku to AWS. Currently, DNS is being handled by Route53, with a CNAME record sending traffic to the heroku SSL subdomain. I need to change this to an A ...
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Is there a way to force A-record removal in DNS from client server?

Is it possible to initiate deleting of DNS A and PTR records in DNS from member server?
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CloudFlare offers DNS root CNAMEs. Any resolution gotchas to be aware of?

I'm not that familiar with the inner workings of DNS, preferring to just add my CNAMEs and A records as appropriate, and leave the behind the scenes to other services. I host a few sites on Amazon S3, ...
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Why use CNAME in Route 53+S3 combination

I have been going through Amazon's docs on using Route 53 in conjunction with S3 to serve static websites. The strategy they show is to do: example.com A -> alias to ...
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1answer
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Is it possible to simplify my website DNS records?

Let's say I have mydomain.com and my shared webhost server is 1.2.3.4. My domain registrar and webhosting company are 2 different entities. Currently I have my DNS records configured like this in my ...
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1answer
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MX and A Records

Just a quick question about A and MX records. If I have a domain that I have purchased, and I want to get remote mail working eventually, to say: mail.exampledomain.com, do I just put in with my ...
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nginx www.domain.com vs domain.com virtualhost

I have an http block where I include virtual hosts for the different domains hosted on the same server. For each virtual host I do: listen domain.com:80; Now, domain2.com works fine. However, when ...
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Is there any way to point an A record of a web page to another website when that other website is on shared hosting?

I am creating a web application that at this point I am using shared hosting to host. Is there any way for me to give my users the option to point the a record of their domain to my website and I ...
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Subdomain and CNAME

I have a website foo.com and now I have setup a sub-domain sub.foo.com. I can open foo.com and its fine but when I try to open or ping sub.foo.com its not happening. I cant even FTP into sub.foo.com. ...
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splitting A and MX records

I have a domain name which currently points to a shared hosting service. I've set up a dedicated Apache server for the web hosting, but would like to keep using the mail server of the old host. Is ...
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A and PTR records and redundant Internet connections

Want to set up PTR record(s) to handle the following: Site with mail server (Exchange 2010) has three Internet connections, with the firewall handling load balancing. I know that if the Internet ...
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what is an A record and how it is related to DNS?

i dont know what A records do. and are they necessary for a web server to host multiple domains and how are they related to DNS?
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Sending an Email from 2 Mail Servers

We are currently attempting to move away from using a "local" mail(exchange) server to an cloud based offering for all our automated emails. The problem is that we send and receive thousands for ...
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how do you add an A record for a root domain

this seems really simple, but I can't figure it out. I'm using xname.org since it's free and I own a bunch of domains spread over a few different registrars. The setup I desire is very simple: one A ...
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1answer
238 views

DNS not resolving for root domain, only for subdomains

The domain I'm having issues with is rossmasters.com. Here's what happens when I attempt to resolve the root domain and a subdomain: C:\Users\Ross>nslookup rossmasters.com Server: UnKnown ...
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Preventing MX record fallback

I have a website, example.com, running on a Windows 2008 server with IIS 7 and the "IIS 6" SMTP service. The website regularly sends out emails to info@example.com. In rare instances, the MX record ...
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Domain resolving problem

I have registered a new domain. I want to use it with my server. I have a static IP for my server. Using my registrar control panel I have added an A record for my domain.com with value IP of my ...
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Pingdom error: “No delegation could be found at the parent” when analyzing subdomain

I have a subdomain dramarsarin.crimsonandcyan.com which i wanted to point to another server. I added an A record in the zone file for crimsonandcyan.com with the host 'dramarsarin' and pointed it to ...
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Multiple DNS A records referencing the same host

If I create multiple DNS A records for the same hosts, for example: my-domain.com A 1.2.3.4 3600s my-domain.com A 4.5.6.7 3600s my-domain.com A 7.8.9.0 3600s Do queries really ...
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Bootstrapping A Records for a DNS Server

My problem is this. Dissatisfied with the existing free DNS nameserver solutions, I decided to make my own nameservers for my websites. I'm using NSD on Debian, and it's working great. I can request ...
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Change DNS A records dynamically

For example, I'll buy domain name at godaddy.com. I'll configure it with 2 A records with IPs 123.0.0.1 and 123.0.0.2. Is it possible to ping it for availability and change A records dynamically by ...