smtp IN A 203.98.94.10
www IN CNAME @
ftp IN CNAME @
mail IN CNAME smtp
pop IN CNAME smtp
pop3 IN CNAME smtp IN MX 100 smtp2.anchor.net.au. IN MX 50 smtp1.anchor.net.au. IN NS ns2.anchor.net.au. Minimum
@ IN NS ns1.anchor.net.au; expire
86400 ) ; retry
3600000 ; refresh
14400 ; serial
28800 ; (
2004030401 . hostmaster.anchor.net.au. So what does a domain record look like
@ IN SOA ns1.anchor.net.au. And may not update instantly), some ISP's do not confirm to the standard for DNS caching, regardless of the domain name (note, this means the whole Internet will see the change in 10 minutes. Changing them on the new DNS server, and then when you are ready for the website and email to go to the new server, (ten minutes or so), with a very low TTL, and that is to redelegate a week early with your new hosting company copying the old records, there is a way to speed up the process, as I said above. This process of waiting for all the Internet to see your move is called propagation. Au''' domains are updated instantly. Whilst the ''', uSA time, no server will see the change until the DNS system reloads at midnight, org''' domains. , net. , com. Additionally for '''. Once the TTL period expires the servers will then see the new details, which it generally is (around the 1 day mark) then any DNS server that has requested information on your domain in the past 24hrs will still see the old records; if this value is high. The amount of time it takes depends on the TTL value in the old server, when you redelegate your domain from one DNS server to another. Without asking if it has changed (the process known as caching), and it is the maximum time a foreign DNS server can store this information locally, tTL stands for '''Time To Live'''. Along with a TTL value, and when another DNS needs information about your domain it is pulled from this file, the DNS server responsible for your domain has a file with all the information about your domain in it, in plain English. But what do they mean, '''Cache''' and '''Propagation''' come up, '''TTL''', the words (and abbreviations), often when talking about DNS? Translated, buzzwords and Geek words! And a week long changeover, this is avoidable through careful planning. Some will go to the old server, some email will go to the new server. Some people will still see the old one, some people will see the new site, for a period of 3 days, suffice to say. The reason for this is explained in the next paragraph. It can take quite a while for other people to realize), (The same as when you move house. It can take up to 3 days for the rest of the Internet to notice you have moved, depending on the type of domain, once the change is made. It is a simple change, this is done through a web page of the company that you registered the domain with, generally. You need to change that information, and you need to bring it to Anchor, if your domain is currently with another company. Customers of Anchor should always see '''ns1.anchor.net.au''' and '''ns2.anchor.net.au''' in their whois information. But it will show you which DNS servers know where it is, a whois search will not show you where your website is. You need to do a ''whois search'', to find out who your domain is delegated to. So no one notices, they can also update the DNS records straight away, for instance moving it onto a faster server, and if they make a change to the location of your website, as it means one company handles everything for you, is best, known as redelegation, this procedure. The normal procedure is to also change your domain's delegation to the new hosting providers DNS servers, changing DNS Servers
When you change hosting providers. Before passing it back to you, then it asks that DNS server for the information it needs, which DNS server does know about this domain, it asks the master servers, when you look for a domain that your ISP's DNS server does not know, that contain a list of which DNS servers handle which domains, there are a lucky 13 master servers. No one server holds the records for every single domain, dNS works on a distributed basis, as I said. Your ISP's mail server does a DNS search to find the mail server for that domain, every time you send an email. You do a search of the DNS system to find the location of the site, every time you go to a website. 99% of them without even knowing, every single person on the Internet uses DNS. They probably have their own directory assistance too), 000+ employees, having 30, (of course. HP all have their own servers, dell, ie Microsoft, and a lot of large businesses, most hosting companies do as well, virtually every Internet provider has two or more DNS servers, the DNS system is distributed across the whole Internet. Which translate phone numbers to names, or directory assistance, the theory is similar to a phone book. To human readable names, dNS is a translation service from computer readable names, dNS Tutorial - A Guide to Understanding DNS and Zone Records
DNS in a nutshell
As I said above.
( hostmaster.anchor.net.au. Lets breakdown the file one line at a time
@ IN SOA ns1.anchor.net.au. What does it all mean? That looks scary!
Minimum as these are not important in this situation
86400 ) ; maximum and Serial''', retry, and that
hostmaster@anchor.net.au is the contact for this server
Skip the next 4 lines: '''Expire, states that ns1.anchor.net.au is the domain server responsible for your domain, the Start of Authority, this line,
Other servers can cache the information for your domain
@ IN NS ns1.anchor.net.au, ie the length of time, the value of minimum is the TTL.
IN MX 50 smtp1.anchor.net.au. NS lines give a list of all the nameservers responsible for your domain. This line means that your server is listed in ns1.anchor.net.au (and below that in ns2.anchor.net.au), means nameserver, nS, the third column on this line.
The higher the priority
IN A 202.4.234.122 the lower the number, the number after MX is the priority, and MX lines are a list of servers that handle your email, mX stands for Mail eXchange, (all your records should say IN), the column after IN is important, again,
Mail IN CNAME smtp If it has a * it means every subdomain of '''yourdomainname.com.au''' that's
available. It means just '''yourdomainname.com.au''', if it doesn't have a word. Ie '''http://www.yourdomain.com.au''', that is a host name, if the line starts with a word. All A records are direct translations of names to numbers. A means Address, on this line.
Then your email and website are offline too, and it goes down for whatever reason, but if you only have one server, then your website and email are unaffected; but the others are still working, this is for redundancy: if one server dies. And some have up to 10, you may notice in a whois search that most domains have 2 DNS servers listed. You are probably better off letting someone else handle it, and if that doesn't make any sense to you, if you have a static IP address and a permanent Internet connection you can host your own DNS. Can I do this myself? Who is typically your web hosting company, that is the job of your DNS administrator (often called hostmaster), you do not need to understand how the entire system works. My email will be scattered, it takes 3 days, when I redelegate, ie, you only need to have an understanding of the top level of the system, however as I said at the start of this article. It is unavoidable. You must have DNS records, and email you, it all seems so complicated
If you want people to see your website. Do I have to have this? Now don't you feel enlightened? The record tells computers looking for mail.yourdomain.com.au to go look for smtp.yourdomain.com.au instead, in this case, as thats what it means. See-Name, ie; it is often easier to think of it phonetically, whilst this stands for Canonical Name, the final record type is CNAME.
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