Private Zone quick start - private DNS resolution in VPC - Alibaba Cloud DNS

Configure Private Zone to resolve a domain name to a private IP address within a VPC.

Workflow

Prerequisites

A VPC and a vSwitch have been created. For this tutorial, use the CIDR block 192.168.0.0/16 for the VPC and 192.168.0.0/24 for the vSwitch. Create and delete a VPC and a vSwitch.
An ECS instance has been created in the VPC to host a demo service. Note its private IP address (for example, 192.168.0.83). Resources within the same VPC (such as vpc-hangzhou) can access the service at demo.example.com. Purchase and use an ECS instance.

Procedure

Step 1: Add a zoneUser Defined Zones

Sign in to the Alibaba Cloud DNS console for Private Zone.
In the left-side navigation pane, choose Authoritative Zone > User Defined Zones. Then, click Add Zone.
On the Add Zone page, configure the following parameters.

Authoritative Zone: Enter example.com.

Recursive Resolution Proxy for Subdomain Names: Keep enabled (default).

Leave other parameters at their defaults.

Important
You can change the effective scope at any time. We recommend that you configure the scope after adding DNS records.

If a VPC is linked to a zone with no records, DNS queries for the domain from that VPC fail because they are not recursively forwarded to public DNS servers.

Step 2: Add a DNS record

Sign in to the Alibaba Cloud DNS console for Private Zone.
Navigate to Authoritative Zone > User Defined Zones. Find your zone and click Settings in the Actions column.
On the Settings tab, click Add Record and configure the following parameters.

Record Type: Select A.

Hostname: Enter demo.

Record Value: Enter 192.168.0.83.

Set Request Source to Default, TTL to 1 Minute, and Record Value Load Balancing Policy to Round-robin.

Step 3: Configure effective scope

Sign in to the Alibaba Cloud DNS console for Private Zone.
Navigate to Authoritative Zone > User Defined Zones. Find your zone and click Effective Scope in the Actions column.
In the Effective Scope panel, select the VPC that you want to associate with this zone.

In the Effective Scope Settings dialog:
- Effective within Alibaba Cloud VPC: Select the VPCs that you want to associate from the drop-down list (for example, a VPC in the China (Hangzhou) region). You can add multiple VPCs. The + VPC Private Zone DNS Resolution Management (Cross-account) link is provided for cross-account association.
- Effective within Self-managed DNS Cluster: Select a deployed self-managed DNS cluster from the drop-down list. This is applicable to enterprise IDC private network scenarios. You can click Deploy Now to deploy a cluster.
Note
We recommend that you set the effective scope after you configure DNS records to avoid resolution failures caused by empty domain names. The VPC data in the drop-down list may have a latency. If the data is not synchronized, try again after 30 minutes.

Step 4: Verify resolution

Create another ECS instance in the same VPC for testing. Purchase and use an ECS instance.

curl demo.example.com

The following output is displayed:

[ecs-assist-user@iZbp1g6oqu352zapdvhqe0Z ~]$ curl demo.example.com
<!DOCTYPE html>
<html>
<head>
<title>HTTP Server Test Page</title>
<style>
    body {
            width: 35em;
            margin: 0 auto;
            font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to HTTP Server Test Page!</h1>
<p>If you see this page, the httpd web server is successfully installed and working. Further configuration is required.</p>

<p><em>Thank you for using apache httpd.</em></p>
</body>
</html>

If the correct IP address is returned, the configuration is successful.

If no service is running on the destination instance, run ping demo.example.com to verify DNS resolution.

Example output:

[root@iZbp1xxx          ~]# ping demo.example.com
PING demo.example.com (192.168.0.83) 56(84) bytes of data.
64 bytes from iZbp17420etyxud5tvupr2Z (192.168.0.83): icmp_seq=1 ttl=64 time=0.014 ms
64 bytes from iZbp17420etyxud5tvupr2Z (192.168.0.83): icmp_seq=2 ttl=64 time=0.025 ms
64 bytes from iZbp17420etyxud5tvupr2Z (192.168.0.83): icmp_seq=3 ttl=64 time=0.026 ms
64 bytes from iZbp17420etyxud5tvupr2Z (192.168.0.83): icmp_seq=4 ttl=64 time=0.025 ms