Configuring DNS Traffic Control

Infoblox DNS Traffic Control (DTC) provides a load balancing solution by creating DNS responses based on DNS query source IP, server availability, and network topology. Through DTC, you can set up multiple sites in different subnets and configure supported objects and load balancing methods to direct DNS clients to the best available servers.

DNS Traffic Control utilizes a load balancing mechanism to create DNS responses. It returns tailored DNS responses based on settings you configure for associated objects such as DTC servers, pools, and LBDNs (Load Balanced Domain Name). You can configure load balancing methods for pools and LBDNs based on the source IP address and other criteria.

The following diagram illustrates the basic concept of DNS Traffic Control and how you can use it to direct DNS clients to the best available server using the Topology load balancing method. In the illustration, consider your company have six branches in two locations. Each branch offers the same services and applications your users need. To optimize server utilization and minimize response time, you use DNS Traffic Control to provide DNS responses based on the source IP address. You define services in each branch as DTC server objects, and then add them to a pool based on their locations. Branches 1-3 go into Pool A while branches 4-6 go into Pool B. You also create a topology ruleset that is used when you configure Topology as the load balancing method for your LBDN and pools. Here we assume we can specify subnets for each pool that are closer to the pool than the other (subnet 1 is near pool A, while subnet 2 is near pool B, and son on). To ensure that your data centers are healthy, you also configure health monitors so that your pools can check the health of its DTC servers.

In DNS Traffic Control, complete the following to set up the above configuration:

1. Create DTC Servers. Create a server for each location. DNS Traffic Control synthesizes DNS records for the servers.

2. Create Pools. Create a pool for each region. A pool is a collection of servers that you can put together as possible responses to queries.

3. Create Topology rules. A topology rule links specific subnets to a particular pool.

4. Create Policies. A Policy consists of one or more pools, or one or e more topology rules.

5. Create LBDN. A DTC LBDN is a load balanced domain name object that is used by DNS Traffic Control to process DNS queries for load balanced resources.

Following is a brief description of the DNS Traffic Control querying process:

1. Based on the FQDN in the DNS query, the DNS Traffic Control querying process selects a matching LBDN. The LBDN corresponds to a particular Policy.

2. Based on the selected Policy’s load balancing method, the DNS Traffic Control querying process selects a healthy pool. It does not select pools that are not healthy or do not have healthy servers associated with it. If pools are not healthy for the selected Policy, the DNS Traffic Control querying process fails to determine the result, and a negative DNS response will be returned to the client.

3. After selecting a pool, the DNS Traffic Control querying process selects a server from the pool, based on the load balancing method that you have selected for the respective pool.

You can perform the following actions: