Configuring Inbound LLB

After enabling LLB for inbound traffic, the system will resolve domains to different IPs based on the sources of DNS requests, and return IPs for different ISPs to the corresponding users who initiate the requests, thus reducing accesses across ISPs. Such a resolution method is known as SmartDNS.

You can enable inbound LLB by the following steps:

1. Enable SmartDNS. This is the prerequisite for the implementation of inbound LLB.
2. Enable ISP dynamic detection. This function allows system to generate a proximity address based on the proximity route. SmartDNS can reference the proximity address of the specified interface to determine the source of DNS requests.
3. Configure a SmartDNS rule table. The smart domain-to-IP resolution is implemented based on the rule table.

Enabling SmartDNS

SmartDNS is enabled by default. To disable or enable the function, take the following steps:

1. On the Navigation pane, click Configure > Network > LLB to visit the LLB page.
2. Click the Inbound tab.
3. In the Inbound LLB page, click Enable SmartDNS or Disable SmartDNS on the upper-left to enable or disable the function.

Enabling ISP Dynamic Detection

To enable ISP dynamic detection, take the following steps:

1. On the Navigation pane, click Configure > Network > Network to visit the Network page.
2. Select an interface from the interface list, and click Edit on the upper-left.
3. In the Interface Configuration dialog, click Advanced tab.
4. Select Dynamic Detection under LLB.
5. Click OK to save the changes.

Note: Only physical interfaces support ISP dynamic detection.

Configuring a SmartDNS Rule Table

The configuration of SmartDNS rule table includes creating a rule table, specifying the domain name, return IP and matching rule. The system resolves domains names into IPs of different ISP links based on the matching rule. You can also edit or delete any configured SmartDNS rule table.

Creating a SmartDNS Rule Table

To create a SmartDNS rule table, take the following steps:

1. On the Navigation pane, click Configure > Network > LLB to visit the LLB page.
2. Click the Inbound tab.
3. In the Inbound LLB page, click New on the upper-left. In the Domain Configuration dialog, configure the following options.
   • Domain: Specifies the domain name that will be resolved smartly. Options include:
     New - Type a domain name into the box. Separate multiple domain names with comma. Each rule table supports up to 64 domain names (case insensitive)
     Import - Select a domain name that is defined in the system from the drop-down list to import its configuration parameters.
   • User ISP: Specifies the ISP to which the request source address will be matched. Options include:
     ISP static address - Select a predefined or user-defined ISP from the drop-down list. If the source address matches any address entry of the ISP, the system will return the specified IP.
     Dynamic detection - Shows it ISP dynamic detection is enabled. For more information about ISP dynamic detection, see Enabling ISP Dynamic Detection.
     

   • Return IP: Specifies the return IP for different request sources. Options include:
     IP - Specifies the return IP. You can configure up to 64 IPs for a domain name.
     Weight - Specifies the weight of the return IP. The value range is 1 to 100. The default value is 1. In the SmartDNS rule table, one domain name might correspond to multiple IPs. The system will sort the IPs based on the weight and then return to the users.
     
   • ISP link: Specifies the proximity address to which the request source address will be matched. If the source address matches any proximity address entry of the interface, the system will return the specified IP. Options include:
     Inbound interface - Select the proximity address to which the request source address will be matched from the drop-down list.
     Track object - Select a track object of interface type from the drop-down list, or create a new track object. When the track object fails, the proximity address on the corresponding interface will also fail.
     
4. Click Add to add the configured SmartDNS rule table to the rule list, or click Delete to delete it from the list.
5. Click OK to save the changes.

Editing a SmartDNS Rule Table

To edit a SmartDNS rule table, take the following steps:

1. On the Navigation pane, click Configure > Network > LLB to visit the LLB page.
2. Click the Inbound tab.
3. In the Inbound LLB page, click Edit behind domain names to edit.
4. Double-click the table lines under domain names to edit weight, inbound interface and track object.
5. Click OK to save the changes.

Deleting a SmartDNS

To delete a SmartDNS rule table, take the following steps:

1. On the Navigation pane, click Configure > Network > LLB to visit the LLB page.
2. Click the Inbound tab.
3. In the Inbound LLB page, select a SmartDNS rule table and click Delete on the upper-left to delete it.