DNS cloud school rising posture! Three advanced uses of authoritative DNS

We often say ,DNS It's about Internet services “ entrance ”, It is the first step of network interconnection ： When the user enters the web address in the browser （URL） after , The browser will delegate the operating system to the specified Web The server sends the request , But the browser must tell the operating system Web Server's IP Address . As shown in the figure below , Users usually input domain name information in the browser , Therefore, the first step for the browser to meet the needs of users is to DNS The server queries the domain name corresponding to IP Address .

Some people say DNS Function is just an item in the list of network standards and protocols , That's because they don't know enough DNS. Nowadays, people can't leave the Internet for business or personal use , With the increase of global Internet use , People adopt or migrate to new and better network technologies , bring DNS Not only provide domain names to IP The parsing service of , It can also undertake the scheduling of Internet resources , The important task of traffic load balancing .

In this issue, cloud school shares authority DNS Three advanced ways to play ： Use authority DNS Realize business dual active scheduling 、 Business intelligent scheduling combined with health detection 、 Multi exit link scheduling .enjoy：

 

 

01：  Business dual activity scheduling

Many enterprises have their own data centers to provide external services . With the increasing volume of business data , One data center cannot load all businesses , Enterprises have chosen “ North and South ” Deploy data center , Provide nearby services for users . In this case , Just ask in DNS Level implementation will “ North ” The flow of leads into “ north ” Data Center ,“ south ” The flow of leads into “ south ” Traffic scheduling function of data center . As shown in the figure below , Beijing client and Shenzhen client request DNS When parsing ,DNS The server is based on the client source IP, Return to a different IP Address result , Bring traffic to different data centers . So as to realize the function of directing the customer's access request to the server with the fastest response speed , Improve site performance .

 

Let's do a simple experiment , Deploy one DNS The server , Two clients , And two servers , As a data center application resource .

Character name	IP Address
DNS The server	10.3.8.27
client A	10.1.101.218
client B	10.3.8.28
Beijing data center server	10.3.8.27
Shanghai data center	10.3.8.29

 

stay DNS Configure the following on the authoritative server ：

ü1.test A 10.3.8.27 ( Beijing data center application address )

ü2.test A 10.3.8.29 （ Shanghai data center application address ）

ü intelligence DNS Strategy ：DNS The server is based on the client source IP Realize the function of static nearest parsing

 

After the rules are configured , We log in to the client respectively A With client B, Verify the analysis results .

 

client A The analysis result is Beijing data center IP：

 

client B The analysis result is Shanghai data center IP：

 

Through the above experiments , We see DNS It can realize the double active intelligent scheduling of the data center .

 

 

02： Business health testing +DNS

The above experiment completed a simple data center double live scheduling . Let's consider the following scenario ： If the Shanghai data center is powered off at a certain time , Unable to provide service ,DNS If the analysis result is still Shanghai Data Center IP, Then the enterprise business will be seriously affected , It may bring great losses to the enterprise . Business health testing +DNS Can effectively solve such a dilemma . The detection equipment detects the real-time status of the data center server , When an exception is detected , adopt DNS Change of analysis results , Introduce analytical traffic into Beijing data in real time , So as to ensure the uninterrupted business of the enterprise .

Here's the picture , We will manually set the policy in the service area of Shanghai data center , Make Shanghai data center server and DNS The server 、 Shenzhen client B Can't communicate properly , It is used to simulate the failure state of application server in Shanghai data center .

 

At this time , We can DNS The service platform sees that the application server status of Shanghai data center is displayed as alarm ：

Then we use the client B Conduct DNS Parse query , As can be seen from the experiment below ,DNS After the server detects the abnormal status of Shanghai Data Center , Automatically introduce all business traffic into Beijing data center , Realize real-time switching of business traffic .

03： Multi exit link scheduling

adopt DNS It can also realize the intelligent analysis and scheduling between multiple lines or the function of traffic load . When enterprises access telecommunications at the same time 、 Unicom 、 When moving the lines of three operators , There will be cross network access between operators' lines , Cross network access will lead to the problem of slow service response . adopt DNS The configuration can guide the users in the network to the corresponding network cache Node or network exit , Thus, the traffic can be guided and scheduled effectively , Improve localization rate , Improve user experience .

 

Let's do another simple experiment , adopt DNS Server management interface , Create mobile phones separately 、 Unicom and telecom view , And specify users from different operators , Different link exits . The following is a declaration of roles 、 Link exits and IP：

Character name / Link exit	IP
client A:	10.1.101.218
client B：	10.3.8.28
client C：	10.3.8.29
Mobile exit	1.1.1.1
Unicom export	2.2.2.2
Telecommunications exports	3.3.3.3

 

Let's use different client identities , towards DNS Server send dns.test Domain name resolution request .

 

Unicom client A request dns.test domain name , The returned result is... Of the Unicom link exit IP：

 

Mobile client B request dns.test domain name , The returned result is... Of the mobile link exit IP：

 

 

Telecom client B request dns.test domain name , The returned result is... Of the telecommunication link exit IP：

 

From the above small experiment, we can see , utilize DNS Intelligent multi outlet link scheduling can be achieved .DNS There are many forms of multi exit link scheduling , for example ： Scheduling scenario based on domain name library 、 Time based scheduling scenario 、 Link state based scheduling and so on , I won't introduce them here . If you want to know how to schedule the above data center double live 、 A scheme based on the combination of service application health detection scheduling and multi exit link scheduling , You can contact our solution experts .