Configuring Custom Lines

Scenarios

Public DNS resolution provides you with more than 300 carrier and region lines. You can also configure custom 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 EDNS matches the configured IP address range of the custom line.
• If IP address scheduling through ISP lines or region lines is inaccurate, you can configure custom lines to address this issue.

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. Go to the Custom Lines page.
2. Click Add Custom Line.
3. 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

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

   The Record Sets tab is displayed.

3. Click Add Record Set.

   The Add Record Set dialog box is displayed.

4. Add two A record sets for example.com. Configure 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. To use an at sign (@) as the domain name prefix, just leave this parameter blank. abc: The domain name is abc.example.com, a subdomain of example.com. mail: The domain name is mail.example.com, which is usually used for email servers. *: 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 specific 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 1 to 2147483647, and the default value is 300. If your service address changes frequently, set TTL to a smaller value.	Default value: 300	Default value: 300
   Value	IPv4 addresses mapped to the domain name. Enter each IPv4 address on a separate line.	1.1.1.1	2.2.2.2
   Tag	(Optional) Identifier of the record set. Each tag contains a key and a value. You can add up to 20 tags to a record set. For details about tag key and value requirements, see Table 3. NOTE: If you have configured tag policies for DNS, you need to add tags to your record sets based on the tag policies. If you add a tag that does not comply with the tag policies, record sets may fail to be created. Contact the administrator to learn more about tag policies.	example_key1 example_value1	example_key1 example_value1
   Description	(Optional) Supplementary information about the record set. The description can contain no more than 255 characters.	-	-

   Table 3 Tag key and value requirements

   Parameter	Requirements	Example Value
   Key	Cannot be left blank. Must be unique for each resource. Can contain no more than 36 characters. Cannot start or end with a space nor contain special characters =*<>\,|/	example_key1
   Value	Cannot be left blank. Can contain no more than 43 characters. Cannot start or end with a space nor contain special characters =*<>\,|/	example_value1

5. Click OK.