Inbound Link Load Balancing
After enabling the LLB for inbound traffic, the system will resolve domains of different IPs based on the sources of the DNS requests and return IPs for different ISPs to the corresponding users who initiate the requests, which reduces access across ISPs. Such a resolution method is known as SmartDNS.
You can enable inbound LLB by the following steps:
- Enable SmartDNS. This is the prerequisite for the implementation of inbound LLB.
- Configure a SmartDNS rule table. The smart domain-to-IP resolution is implemented based on the rule table.
Creating a Smart DNS Rule Table
To create a SmartDNS rule table, take the following steps:
- Select Network > Inbound.
- Click New > Domain Table.
- In the Domain Configuration page, type a domain table name into Domain Table text box.
- Type a domain name into Domain text box. Separate multiple domain names with comma. Each rule table supports up to 64 domain names (case insensitive).
- Click OK.
In the Inbound LLB page, click the domain table name you already created and then click New.
In the New SmartDNS Rule page, configure the following:
Option Description 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, system will return the specified IP. Return IP Specifies the return IP for different request sources. 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. System will sort the IPs based on the weight and then return to the users.
Inbound Interface Specifies the inbound interface for the return IP address. System will judge whether the return IP address is valid according to the track result or the protocol status of the inbound interface. Only the valid IP address will be returned to the request source.
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. When the track object fails, the return IP address is invalid. When there’s track object configured on the inbound interface, if the track status is successful, the return IP address is valid. Otherwise the IP address is invalid. When there’s no track object configured on inbound interface, if the protocol state of the interface is UP, the return IP address is valid. Otherwise the IP address is invalid. If you don’t specify the inbound interface for the return IP address, the return IP address is always valid.
- Click OK.