Configuring Custom Lines

Scenarios

The public zone function provides you with more than 300 carrier and region resolution lines. You can also customize resolution lines based on specific IP address ranges. Usually, a DNS server returns the same IP address to all visitors, irrespective of where they come from. Custom line resolution returns a specific IP address based on the IP address of a visitor.

• If the local DNS server of the broadband service provider used by the visitor does not support the Extension Mechanisms for DNS (EDNS), the authoritative DNS server checks whether the public IP address of the local DNS server matches the configured IP address range of the custom line.
• If the local DNS server of the broadband service provider used by the visitor supports EDNS, the authoritative DNS server checks whether the visitor's public IP address encapsulated in the EDN S matches the configured IP address range of the custom line.

You can configure custom resolution lines to obtain different resolution results based on source IP addresses of visitors.

If your website (example.com) is providing services both for external and internal users, you can configure different resolution lines so that the DNS server can return the external server address (1.1.1.1) to external users and internal server address (2.2.2.2) to internal users.

Add Custom Resolution Lines

1. Log in to the management console.
2. Hover the cursor over in the upper left corner. In the service list, choose Networking > Domain Name Service.

   The DNS console is displayed.

3. In the navigation pane, choose Custom Lines.

   The Custom Lines page is displayed.

4. Click Add Custom Line.
   Figure 1 Add Custom Line
   
5. Configure the parameters based on Table 1.

   Table 1 Parameters for adding a custom resolution line

   Parameter	Description	Value 1	Value 2
   Line Name	Custom line name	Line 1	Line 2
   IP Address Range	Source IP address range Enter a range of 1 to 50 IP addresses and separate the start and end IP addresses with a hyphen (-).	1.0.0.1-1.0.0.2	1.0.0.3-1.0.0.4

6. Click OK.

Add Record Sets with Custom Lines

For example, add record sets for example.com with Line 1 (to IP address 1.1.1.1) and Line 2 (to IP address 2.2.2.2).

1. Log in to the management console.
2. Hover the cursor over in the upper left corner. In the service list, choose Networking > Domain Name Service.

   The DNS console is displayed.

3. In the navigation pane on the left, choose Public Zones.

   The Public Zones page is displayed.

4. On the Public Zones page, click the domain name (example.com) of the public zone.

   The Record Sets page is displayed.

5. Click Add Record Set.

   The Add Record Set dialog box is displayed.

   Figure 2 Adding an A record set
   

6. Add two A record sets for example.com. Set the parameters based on Table 2.

   Table 2 Parameters for adding an A record set

   Parameter	Description	Line 1	Line 2
   Name	Prefix of the domain name to be resolved. For example, if the domain name is example.com, the prefix can be as follows: www: The domain name is www.example.com, which is usually used for a website. Left blank: The domain name is example.com. In some cases, you may need to set the record set name to the at sign (@). However, the at sign is not supported. Leave the Name blank. abc: The domain name is abc.example.com, a subdomain of example.com. mail: The domain name is mail.example.com, which is typically used for an email server. *: The domain name is *.example.com, which is a wildcard domain name, indicating all subdomains of example.com.	www	www
   Type	Type of the record set	A – Map domains to IPv4 addresses	A – Map domains to IPv4 addresses
   Line	The DNS server will return the IP address of the specified line, depending on where the visitors come from. Default: returns the default resolution result irrespective of where the visitors come from. ISP: returns the resolution result based on visitors' carrier networks. For details, see Configuring ISP Lines. Region: returns the resolution result based on visitors' geographical locations. For details, see Configuring Region Lines. Custom Lines: Return the resolution result based on specified IP address ranges.	Resolution Lines_Line1	Resolution Lines_Line2
   TTL (s)	Cache duration of the record set on a local DNS server, in seconds. The value ranges from 300 to 2147483647, and the default is 300. If your service address changes frequently, set TTL to a smaller value.	The default value is 300s, which is, 5 minutes.	The default value is 300s, which is, 5 minutes.
   Value	IPv4 addresses mapped to the domain name Every two IPv4 addresses are separated using a line break.	1.1.1.1	2.2.2.2
   Tag	(Optional) Identifier of the record set. This parameter is displayed when you expand More Settings. Each tag contains a key and a value. You can add a maximum of 10 tags to a record set. For details about tag key and value requirements, see Table 3.	example_key1 example_value1	example_key1 example_value1
   Description	You can enter a maximum of 255 characters.	N/A	N/A

   Table 3 Tag key and value requirements

   Parameter	Requirements	Example Value
   Key	Cannot be left blank. Must be unique for each resource. Can contain a maximum of 36 characters. Cannot start or end with a space or contain special characters =*<>\,|/	example_key1
   Value	Cannot be left blank. Can contain a maximum of 43 characters. Cannot start or end with a space or contain special characters =*<>\,|/	example_value1

7. Click OK.