DNS, Domain Name System or Domain Name Service (Domain Name System or Domain Name Service). The domain name system assigns domain name addresses and IP addresses for hosts on the Internet. Since both the computer in the network must have an IP address, this can communicate with each other, but let us remember a large string of IP address to access the website is obviously impossible, so the user uses the domain name address, and the DNS system is functional The domain name address is automatically translated into an IP address. The domain name service is an Internet tool that runs domain name system. The server that performs domain name service is called the DNS server, and the domain name service is replied to the DNS server.
1. DNS is a domain name server. His task is to determine the resolution of the domain name, such as a record MX record, and more.
2, there is at least one DNS in any domain name, usually 2. But why do you have more than 2? Because DNS can be reincarnated, the first parsing fails can be found. This will not affect the normal use of the domain name as long as there is a DNS parsing.
3, how to determine the DNS of the domain name
Very simple to www.internic.net/whois.html Enter the domain name you want to query. This is the International Domain Management Center. The only authority. As long as you can find a domain name here, it means that the domain name is effective. It said when you expire, is it when it expires.
4. Effective DNS means who is currently working, for example, query results are ns.xinnetdns.com, ns.xinnet.cn (new Net Xinhai) means that the current domain name is from ns.xinnetdns.com, NS .Xinnet.cn (new Net Xinhai) is responsible for analysis. Other unselected DNS settings are invalid.
5, DNS can be modified. After 24-72 hours later, all DNS servers worldwide will be refreshed. The information of INTERNIC is usually seen after 24 hours. In addition, the modified process does not mean that the domain name will stop resoluntation, as long as you do it on the 2nd. If it takes effect, it is a new DNS works. If there is no effective. It is the old DNS works. Either take effect or not take effect. There is no time that you don’t work. So domain name resolution does not interrupt. The premise is that both sides have parsed.
Address record, used to specify the IPv4 address of the domain name (eg 8.8.8), if you need to point the domain name to an IP address, you need to add a record.
The IPv6 address used to specify the host name (or domain) (for example, FF06: 0: 0: 0: 0: 0: 0: C3) record.
CNAME (Canonical Name) Record, ie: alias record. This record allows you to map multiple names to the same computer. It is often used to provide a computer that provides both WWW and MAIL services. For example, there is a computer named host.mydomain.com (record). It offers WWW and MAIL services, in order to facilitate user access services. Two alias (CNAME) can be set for the computer: WWW and MAIL. The full name of these two aliases is www.mydomain.com and mail.mydomain.com. In fact, they all point to Host.Mydomain.com.
MX records are also called mail routing, and users can point to the mail server under this domain to their Mail Server, then you can control all mailbox settings. You only need to fill in the IP address of your server online, you can transfer all your domains to your own settings on the appropriate mail server.
Simply put, by operating the MX record, you can get a post office ending with your domain name.
TXT records, generally refer to a description of a hostname or domain name, where you can fill in anything, length limit 255.
Admin In TXT “Administrator, Tel: 13901234567”
Mail in txt “mail host, stored in XXX, Manager: AAA”
Jim in txt “Contact: [email protected]”
That is, you can set TXT to make others contact you.
Most of the TXT records are used to do SPF records (anti-spam).
Subdomain truth equivalents, but more extension than secondary domain names, such as we continue to expand the host name of the domain name, set the host name BBS.at, then create a three-level domain name: bbs.at.abc.com Of course, it is also possible to establish four-level domain name bbs.at.go.abc.com, five domain name bbs.at.go.home.abc.com … The subdomain name of the top domain name abc.com. Urban name and general solution
The pan-domain name refers to the root of a domain name, indicating all unsteaded subdomain names of this domain name root in the form of * .domain.com.
Spreadsheet is to resolve * .domain.com A record to an IP address, and then others can access the site on your resolution through any prefix. Domain.com accessed.
The root domain name name.com only established two domain records of www.name.com and name.com, then ftp.name.com, mail.name.com, bbs.name.com and other domain name records do not exist. But for root domain name name.com, establish a pan-domain record * .name.com, * .name.com, all non-existent subdomains that are ftp.name.com, mail.name.com, bbs.name.com. Record. You can define * .name.com to point to an IP, then visitors will directly access your definition directly when the visitor is input ftp.name.com, mail.name.com, bbs.name.com. The IP of .com.
What needs to be explained here is that if a subdomain resolution is set separately, for example, the host name is set to Mail, and the resolution record is higher than the priority of the resolution record. The alias record (CNAME record) does not support general analysis.
Domain name binding
Domain name binding refers to the space of the domain name and host (ie, a server), which is actually set on the virtual server or set on the web server, so that a domain name is booted to a particular space on the server (one Specific site), when the visitor accesses your domain, you will open the web page you stored in this space. It is actually parsing the domain name to the server IP, and then sets the domain name to have permission access. A typical virtual host has a control panel to bind domain names.
Domain Names Turn to We are also known as a domain name (URL) pointing or domain name forwarding, when entering your domain name in the user address bar, you will automatically jump to another network address (URL) you specified.