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Clearing DNS Cache

Note

From NIOS 9.0 onwards, IB-4030 and IB-4030-10GE appliances are not supported.
Similar features and functionalities are available on software-based DNS Cache Acceleration appliances, and it is recommended to use the software-based DCA supported appliances. For a list of supported appliances, see as described in Supported DNS Cache Acceleration Appliances.

The IB-4030 or IB-4030-10GE appliance allows you to clear certain information from the DNS cache. You can do the following:

The appliance saves audit log entries for all the three clear cache operations. For information about audit logs, refer to the Infoblox NIOS documentation at https://docs.infoblox.com.

Clearing DNS Cache

On the DNS Cache Acceleration appliance, you can clear all entries from the accelerator cache and the name server recursive cache.
To clear DNS cache:

  1. From the Data Management tab, select the DNS tab -> Members tab -> member check box.
  2. Expand the Toolbar, click Clear -> Clear DNS Cache.
  3. Click Yes in the confirmation dialog box to clear DNS cache.

Clearing Cache for DNS Views

This feature clears cache entries of a specific DNS view that is associated with the selected member. To clear cache of a DNS view:

  1. From the Data Management tab, select the DNS tab -> click the Members tab.
  2. Expand the Toolbar, click Clear -> Clear View's Cache.
  3. Specify the following in the Clear View's Cache dialog box:
    • Member: Click Select Member to select a member. If there are multiple members, the Member Selector dialog box is displayed, from which you can select a member. Click the required member name in the dialog box. You can also click Clear to clear the displayed member and select a new one.
    • DNS View: Select a DNS view from the drop-down list. This list box appears only when there are multiple DNS views in the network view.
    • Click Clear Cache to clear the cache entries of the corresponding DNS View.

Clearing Domains and Subdomains from DNS Cache

You can use this feature to clear specific domain and its subdomains from the DNS cache. To clear a domain name:

  1. From the Data Management tab, select the DNS tab -> click the Members tab.
  2. Expand the Toolbar, click Clear -> Clear Domain Name.
  3. Specify the following in the Clear Domain Name from Cache dialog box:
    • Domain Name: Enter a domain name you want to delete.
    • Clear entire domain (including subdomains): Select the check box to clear the specified domain and its subdomains from the DNS cache. For example, if you enter corp100.com in the Domain Name field, then selecting this check box clears the entire domain including its subdomains such as www.xyz.com, xyz.com, x.xyz.com, etc. This check box is deselected by default.
    • Member: Click Select Member to select a member. If there are multiple members, the Member Selector dialog box is displayed, from which you can select a member. Click the required member name in the dialog box. You can also click Clear to clear the displayed member and select a new one.
    • DNS View: Select a DNS view from the drop-down list. This list box appears only when there are multiple DNS views in the network view.
    • Click Clear Domain Name to clear the domain name from the cache.

Viewing the DNS Accelerator Cache

You can view the cached contents of the DNS accelerator. The NIOS appliance temporarily disables the cache to obtain the current cache data. During this time, the non-accelerated name server on the appliance responds to all incoming DNS queries. Depending on the size of the cached data, it may take 40-50 seconds to compile information before the cache is re-activated.
Your browser may need to be set to allow popup windows from the IP address of the appliance.

The DNS Cache Acceleration processes incoming EDNS0 packets that contains the local ID, matches it with the DNS server as part of the RADIUS accounting message and populates the subscriber cache in DNS Cache Acceleration with the parental control policy information. For more information, refer to the NIOS documentation at docs.infoblox.com.

The cache data appears in plain text format, showing the following DNS response information:

  • DNS View Number (0-5)
  • Query question,Query type, and Query class
  • Original TTL in seconds
  • Remaining TTL in Seconds
  • Cache Entry Usage Count
  • Number of Seconds since the cache entry was last addressed
  • Recursion
  • Resource Record section, Type, Name, TTL, and Data
  • Rcode indicates Response Code and displays 0 if there are no errors.
  • Debug<1> and Debug<2> codes are used for debug purpose.
  • PCP word - valid for subscriber services.
  • Data based on the type of resource record(s) attached to the response:
    • A type and AAAA Filtered – IP address
    • CNAME, SOA, PTR – Domain Name
    • MX – Preference, Domain Name

To view the contents of the DNS Accelerator's cache, do the following:

  1. From the Data Management tab, select the DNS tab and click the Members tab -> member check box.
  2. Choose View -> View Acceleration Cache.
  3. Click Yes in the View Acceleration Cache dialog.
    The system displays a File Download was Successful message and the cache data is displayed in table format in a new browser tab or browser window.