A record, MX record, CNAME record, URL forwarding, NS record, dynamic record (RPM)

Source: Internet
Author: User
Tags domain name server mail exchange mx record nslookup nslookup command record mx sub domain url forwarding

<title>A record, MX record, CNAME record, URL forwarding, NS record, dynamic record (RPM)</title> A record, MX record, CNAME record, URL forwarding, NS record, dynamic record (RPM) Table of Contents
    • Dns
    • A
    • Aaaa
    • CNAME
    • Mx
    • Txt
    • Sub domain
    • Pan-Domain and pan-resolution
    • URL (Uniform Resource Locator)
    • Ns
    • Dynamic Domain Name resolution



DNS, domain Name System, or domain Name Service (domain Name System or nameservers). Domain Name systems assign domain addresses and IP addresses to hosts on the Internet
because computers in the network must have an IP address, this Kind of communication between each other, but let us remember a large list of IP addresses to access the site is obviously not possible, so users use domain name address,
and the function of the DNS system is to automatically translate the domain name address into the IP address domain Name Service is the Internet tool that runs the domain Name System. Server that executes the domain name service Called a DNS server, answering queries for domain name services by using a
DNS server

    1. DNS is the domain name server, his task is to determine the domain name of the resolution, such as A record MX records and so on
    2. Any domain name has at least one DNS, typically 2. But why should it be more than 2? Because DNS can be processed in a recurring way, the first parsing failure can be found in the second. So as long as there is a
      DNS resolution is normal, will not affect the normal use of the domain name
    3. How to determine DNS for a domain name
      Very simple to www.internic.net/whois.html input you want to query the domain name can be seen. This is the International Domain name Management Center. The only authority. As long as we can find a domain name here,
      Indicates that the domain name is in effect. It says when you expire, that's when it expires.
    4. A valid DNS indicates who is currently working on the DNS server, such as the query result is NS. Xinnetdns.com. NS. Xinnet. CN (new net letter sea) means that the current domain name is the
      Ns. Xinnetdns.com. NS. Xinnet. CN (new net letter sea) is responsible for parsing. Other DNS settings that are not displayed are not valid
    5. DNS can be modified. After 24-72 hours of modification, all DNS servers worldwide can be refreshed. InterNIC's information is usually visible after 24 hours.
      In addition, the process of modification does not mean that the domain name will stop parsing, as long as you are on the 2 side of the parse. If this is the case, the new DNS is in effect. If it does not take effect. Is that the old DNS is working.
      Either to take effect or not to take effect. There are no 2 times that do not work. So domain name resolution, will not be interrupted. The premise is that both sides have done the parsing

The IP point of the WEB server
A (address) record is used to specify the host name (or domain name) corresponding to the IP address record
Description: A user can point a Web server under that domain name to its own Web server. You can also set your own domain name level two domain name
is said: Through A record, you can set their own different domain names to go to different IP up! Such as:

Www.yourname.com go to IP 321.32.321.321
Ftp.yourname.com go to IP
Mail.yourname.com go to IP


Reference A, which specifies the host name (or domain name) corresponding to the IPV6 address (for example: FF06:0:0:0:0:0:0:C3) record


Canonical name Record, (alias from one domain Name to another) is usually referred to as the alias point
This record allows you to map multiple names to the same computer. Typically used for computers that provide both WWW and MAIL services. For example, there is a computer named Host.mydomain.com (a record)
It also provides the WWW and MAIL services, in order to facilitate user access to services. You can set two aliases (CNAME) for this computer: WWW and MAIL. The full name of the two aliases is
Www.mydomain.com and mail.mydomain.com In fact they all point to host.mydomain.com


Mail Exchange Mail Routing records
Description: Users can point the mail server under the domain name to their own mail server and then control all mailbox settings on their own
Just fill in your server's hostname or host IP address online, you can transfer all the mail under your domain name to the corresponding mail server.
is to separate your domain in the mail server, set it to other IP to go!
For example the same is ourwords.cn, if you set a record to point to, while the MX record you set is to point to,
Then your DNS server will interpret its request to when it receives someone else's mail routing request! While others visit your Web page is still access to


TXT record, generally refers to a host name or domain name setting description, here can fill anything, length limit 255
Such as:
admin in TXT "admin, Phone: 13901234567"
Mail in TXT "email host, store in XXX, Manager: AAA"
Jim in TXT "Contact: [email protected]"
That is, you can set up TXT in order to get someone to contact you

The vast majority of TXT records are used to make SPF records (anti-spam)

Sub domain

Sub-domain name is equivalent to two-level domain name, but more than the two-level domain name extension, such as we continue to expand the hostname of the domain name, set the host name bbs.at, then you can establish a three-level domain name: bbs.at.abc.com,
Of course, you can also establish a four-level domain name bbs.at.go.abc.com, five-level domain name bbs.at.go.home.abc.com., and so on, can establish an unlimited level of domain names, we collectively refer to these domain names as top-level domain
ABC.com Sub-domain

Pan-Domain and pan-resolution

A generic domain name refers to a domain name under the root of *. The domain.com form represents the domain root of all the non-established sub-domains

Pan-Parse is to put *. Domain.com's a record resolves to an IP address, and the other person passes any prefix. domain.com access can be accessed to the site you resolved
Root domain name.com only established www.name.com and name.com these two domain name records, then Ftp.name.com, mail.name.com, bbs.name.com and other domain name records are not exist
However, after establishing a *.name.com for the root domain name name.com, *.name.com covers all non-existent sub-domain records such as ftp.name.com, mail.name.com, bbs.name.com, etc.
You can define *.name.com to point to an IP, and when the visitor enters Ftp.name.com, mail.name.com, bbs.name.com, the visitor will directly access your defined
The IP of the *.name.com

It should be noted here that in our system if a separate sub-domain name resolution, such as the host name is set to mail, resolved to, then the priority of the parse record is higher than the pan-resolution
Alias record (CNAME record) temporarily does not support pan-resolution

URL (Uniform Resource Locator)

Forwarding: URL forwarding, domain name steering
Function: If you do not have a separate server (that is, you do not have a separate IP address) or you have a domain B, you want to access the content of the B domain when you visit a domain, you can use the URL forwarding to achieve
URL forwarding can be forwarded to a directory, or even to a file. And the CNAME is not possible, this is the URL forwarding and the main difference between the CNAME


The name server record is a domain name server record that specifies which DNS server the domain name is to parse
How to view a record of a domain name. MX record. CNAME Records and NS Records
So how to find a record of the domain name, to query the MX record of the domain name. CNAME record or NS record, available nslookup command
Nslookup is Windows Nt/2000/xp and UNIX. commands from Linux and other operating systems. (Not in Windows 98/me)
In the Windows DOS Command Line window, or unix/linux command line, enter Nslookup

where "Default server" and "address" are the DNS server domain names and addresses that are currently being used for Internet access. ">" is a nslookup prompt.
Enter "?" and carriage return at the prompt, you can see the help information of Nslookup, enter "Exit" and return to exit Nslookup. At this point, enter the domain name directly under the prompt, you can find a record of the domain name. For example:
where "non-authoritative answer" means that the query results are returned from the DNS cache.
Enter the set TYPE=MX, and then enter the domain name to query the MX record. For example:
Enter set Type=cname, and then enter the domain name to query the CNAME record. For example:
Enter the set Type=ns, and then enter the domain name to query the NS record. For example:
If you have applied for a top-level domain name or a standalone domain Dynamic resolution service, you can use this method to query whether the settings are in effect after you set the NS record of the domain name as the DNS server for the domain name registrar.
The above operations are from the default DNS server query, if you want to specify the DNS server used by the query, you can enter the domain name, followed by the address of a domain name server
This method of querying applies to all logged queries. If you have applied for a top-level domain or a standalone domain dynamic resolution service in WAN, before you set the NS record for the domain name in your domain registrar,
You can use this method to find out whether your domain name in the WAN network can be resolved properly

Dynamic Domain Name resolution

Refers to the resolution of a fixed domain name to a host with dynamic IP. Machines that surf the Internet at home or in the company, use dynamic Domain name services,
All Internet users can access this computer through a fixed domain name. Online common companies such as peanut shells are provided with dynamic Domain name services

A record, MX record, CNAME record, URL forwarding, NS record, dynamic record (RPM)

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