---
title: "Configuring DNS Cache Acceleration"
canonical: "https://docs.infoblox.com/space/dca9x/399737063/Configuring%20DNS%20Cache%20Acceleration"
format: markdown
---
To achieve optimal DNS query resolution performance, ensure that the switching infrastructure surrounding the DNS Cache Acceleration appliances can handle high performance gigabit ethernet traffic load. To operate efficiently, appliances require switches with adequate memory buffer capacity and support for 1000Base-TX full duplex operation.

> ⚠️ **Note**
> ⚠️ 
> ⚠️ Operation of the DNS caching features requires a DNS Cache Acceleration license. For information about licensing requirements, *[DNS Cache Acceleration Appliance System Configuration](https://infoblox-docs.atlassian.net/wiki/spaces/dca9x/pages/399769902)*.

The DNS service and the DNS Cache Acceleration service are disabled by default on NIOS appliances. They must be enabled after adding the appliance to the network. For information, see *Enabling the DNS Cache Acceleration Service* and *Enabling the DNS Service* sections below.

# Enabling the DNS Cache Acceleration Service

> ⚠️ **Note**
> ⚠️ 
> ⚠️ - From NIOS 9.0.4 onwards, ensure that the **DNS recursion** checkbox is enabled at the Grid/Member/view level before starting the virtual DNS Cache Acceleration service.
> ⚠️ - During NIOS upgrade from older versions to NIOS 9.0.4 and later, ensure that the **DNS recursion** checkbox is enabled at the Grid/Member/view level to start the virtual DNS Cache Acceleration service.
> ⚠️ - If you start the DNS Cache Acceleration Service first, the appliance starts the DNS service and displays a notification.

To enable the DNS Cache Acceleration service on a DNS Cache Acceleration appliance, do the following:

1. From the **Grid** tab, select the **Grid** **Manager** tab and click **DNS** **Cache** **Acceleration**.
2. Select the *Grid_member* check box for the appliance.
3. Click the Start icon to activate the DNS Cache Acceleration service on the appliance.  
If you need to disable DNS Cache Acceleration service: click the Stop icon.

If the DNS Cache Acceleration appliance is an independent appliance, do the following:

1. From the **System** tab, select the **System** **Manager** tab and click **DNS** **Cache** **Acceleration**.
2. Click the Start icon to activate the DNS cache acceleration service on the appliance.

> ⚠️ **Note**
> ⚠️ 
> ⚠️ The appliance displays a warning message if the average DNS Cache Acceleration utilization rate exceeds 85%.

# Enabling the DNS Service

> ⚠️ **Note**
> ⚠️ 
> ⚠️ The DCA (DNS Cache Acceleration) service is dependent upon the DNS service. Thus, when you start the DCA service, the DNS service will start automatically. However, if you start the DNS service first, you must start the DCA service separately. When both services are running on an appliance and you want to stop both services, you can select to stop the DCA service first and then stop the DNS service. If you stop only the DCA service, the DNS service will continue to run. In the same situation when both services are running and you stop the DNS service first, then the DCA service will stop automatically.

To enable the DNS name resolution service for an installed DNS Cache Acceleration appliance in an Infoblox Grid:

1. From the **Grid** tab, select the **Grid Manager** tab, ensure that DNS is selected and select the *Grid_member *check box.
2. Click the Start icon to activate the DNS service on the appliance.  
If you need to disable the DNS service, click the Stop icon.
3. Save the configuration.
4. Click **Restart** when it appears at the top of the screen.

If the appliance is an independent appliance for the network, do the following:

1. From the **System** tab, select the **System Manager** tab, ensure that DNS is selected and select the *Grid_member* check box.
2. Click the Start icon to activate the DNS service on the appliance. To disable DNS, click the Stop icon.
3. Save the configuration.
4. Click **Restart** if it appears at the top of the screen.

# Specifying Grid-Level DNS Cache Acceleration Settings

Each DNS response cached in the DNS Cache Acceleration appliance has its own TTL (Time-To-Live) value. For example, entering a value of 3599 seconds (1 hour-1 second) ensures that the appliance caches all DNS responses with a defined TTL of one hour (3600 seconds) or greater. All DNS responses with TTL values of 3599 seconds or less will not be cached by the appliance, and will instead be cached by non-accelerated cache server.  
To specify Grid DNS Cache Acceleration settings:

1. From the **Data** **Management** tab, select the **DNS** tab, expand the Toolbar and click **Grid DNS Properties.**
2. In the *Grid* *DNS* *Properties* editor, click **DNS** **Cache** **Acceleration**.
3. By default, the **Don't** **Cache** **Records** **with** **TTL** **Less** **Than...** setting defaults to a value of One (1) second. The maximum permissible value is 65000 seconds (slightly over 18 hours).
4. Enter the new TTL value in the **Don't** **Cache** **Records** **with** **TTL** **Less** **Than...** field.
5. Save the configuration and click **Restart** to restart services.

# Specifying Member-Level DNS Cache Acceleration Settings

The TTL setting on the Member page applies only to an independent appliance.  
To modify the TTL cache setting for the appliance, select the **Override** option. By doing so, the new caching value supersedes the value specified at the Grid level. If you select the **Override** option and do nothing else, the appliance inherits its settings from the Grid.  
To specify DNS Cache Acceleration settings for the member:

1. From the **Data** **Management** tab, select the **DNS** tab -> **Members** tab -> *member* check box.
2. Click **Edit**.
3. In the *Member* *DNS* *Properties* editor, click **DNS** **Cache** **Acceleration**.
4. By default, the **Don't** **Cache** **Records** **with** **TTL** **Less** **Than...** setting is defined to inherit its value from the global Grid setting. The **Override** button is associated with this field.
5. To modify the TTL value, click **Override**. The field is enabled and the button changes to **Inherit**.
6. Enter the new TTL value in the **Don't** **Cache** **Records** **with** **TTL** **Less** **Than...** field. The maximum permissible value for this setting is 65000 seconds (slightly over 18 hours).
7. To use the caching TTL value used across the Grid, click **Inherit**. The button changes to **Override** and the field is disabled.
8. Save the configuration.