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Enabling Recursion for RPZs

For RPZ rules to function properly, you must enable DNS recursion. You can enable DNS recursion at the Grid, member, or DNS view level. To enable recursion:

Configuring RPZs for All Recursive Servers

When you configure a local or FireEye integrated RPZ, you must define an internal primary name server. The primary name server can be either recursive or non-recursive, depending on its usage. When you configure an RPZ feed, you must define an external primary name server. You can associate a name server or a name server group with the local RPZ, RPZ feed, or FireEye RPZ. You can also configure RPZs and RPZ feeds for all recursive servers in the Grid.
A local RPZ can have one or more secondary name servers associated with it. For an RPZ feed, you must create an external primary name server.
To configure a local RPZ, or RPZ feed, or FireEye RPZ for all recursive servers, complete the following:

  1. From the Data Management tab, select the DNS tab -> Response Policy Zones tab, and then click the Add icon.
  2. Enter the Response Policy Zone details and click Next to associate an RPZ with at least one name server. For information about creating a local RPZ, see Configuring Local RPZs. For information about creating an RPZ feed, see Configuring Local RPZs. For information about creating a FireEye integrated RPZ, see Configuring FireEye RPZs.
  3. Select All Recursive Name Servers from the list to add all the recursive name servers in the Grid as the secondary name servers for the corresponding zone.

Enabling and Disabling RPZ Query Name Recursion

In previous NIOS releases, RPZ query name recursion was enabled by default. The DNS recursive name server performed RPZ recursive lookups for the fully qualified domain name that was part of an RPZ. Starting with NIOS 7.1.0, RPZ query name recursion is disabled by default. When RPZ query name recursion is disabled, the DNS recursive name server sends responses for the domains being queried, without forwarding queries to the authoritative name servers. This can speed up recursive RPZ lookups by eliminating unnecessary recursions for domains that are known to be malicious, possibly caused by internal DDoS attacks on the recursive server.
You can enable RPZ query name recursion by selecting the Enable RPZ query name recursion (qname-wait-recurse) checkbox. When you select this checkbox, the appliance performs RPZ query name recursions. You can configure this at the Grid, member, and DNS view levels.

Note

RPZ query name recursion is disabled by default. The EnableRPZquerynamerecursion(qname-wait-recurse) checkbox is deselected for all new installations and upgrades. You can select this checkbox to enable RPZ query name recursion.

To enable or disable RPZ query name recursion:

  1. From the Data Management tab, select the DNS tab, and then click Grid DNS Properties from the Toolbar.
    or
    From the Data Management tab, select the DNS tab -> Members tab -> Grid_member checkbox, and then click the Edit icon.
    or
    From the Data Management tab, select the DNS tab -> Zones tab -> dns_view checkbox, and then click the Edit icon.
  2. In the Grid DNS Properties, Member DNS Properties, or DNS View editor, click the General tab -> Advanced tab and complete the following.
    • Enable RPZ query name recursion (qname-wait-recurse): This checkbox is deselected by default, meaning RPZ query name recursion is disabled. When RPZ query name recursion is disabled, the DNS recursive name server sends responses for the domains being queried, without forwarding queries to the authoritative name servers. When you select this checkbox, the DNS recursive name server performs recursive lookups for the fully qualified domain names that are part of an RPZ. To override the value inherited from the Grid, click Override. To retain the same value as the Grid, click Inherit.

3. Save the configuration and click Restart if it appears at the top of the screen.

Following are sample configuration details in the named.conf file when the Enable RPZ query name recursion (qname-wait-recurse) checkbox is deselected:

response-policy {

   zone "local.com" policy Given;# priority 0

   zone "rpz.net" policy Given;# priority 1

   zone "example.com" policy Given;# priority 2
     } qname-wait-recurse no ;

     dnssec-enable yes;

     dnssec-validation yes;

     dnssec-accept-expired no;

   filter-aaaa-on-v4 no;

     zone "." in {
         type hint;
         file "named.cache._default";
   };