Add-Dns Server Query Resolution Policy

Syntax

Add-DnsServerQueryResolutionPolicy
   [-PassThru]
   [-ComputerName <String>]
   [-Name] <String>
   [-Fqdn <String>]
   [-ClientSubnet <String>]
   [-TimeOfDay <String>]
   [-TransportProtocol <String>]
   [-InternetProtocol <String>]
   [[-Action] <String>]
   [-ApplyOnRecursion]
   [-ServerInterfaceIP <String>]
   [-QType <String>]
   [-ProcessingOrder <UInt32>]
   [[-Condition] <String>]
   [-RecursionScope <String>]
   [-Disable]
   [-CimSession <CimSession[]>]
   [-ThrottleLimit <Int32>]
   [-AsJob]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Add-DnsServerQueryResolutionPolicy
   [-PassThru]
   [-ComputerName <String>]
   [-ZoneName] <String>
   [-Name] <String>
   [-Fqdn <String>]
   [-ClientSubnet <String>]
   [-TimeOfDay <String>]
   [-TransportProtocol <String>]
   [-InternetProtocol <String>]
   [[-Action] <String>]
   [-ServerInterfaceIP <String>]
   [-QType <String>]
   [-ProcessingOrder <UInt32>]
   [[-Condition] <String>]
   [-Disable]
   [-ZoneScope <String>]
   [-CimSession <CimSession[]>]
   [-ThrottleLimit <Int32>]
   [-AsJob]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Add-DnsServerQueryResolutionPolicy
   [-PassThru]
   [-ComputerName <String>]
   [-InputObject] <CimInstance>
   [[-ZoneName] <String>]
   [-CimSession <CimSession[]>]
   [-ThrottleLimit <Int32>]
   [-AsJob]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Description

The Add-DnsServerQueryResolutionPolicy cmdlet adds a policy for query resolution to a Domain Name System (DNS) server. A policy determines the resolution of queries based on criteria that you specify in the policy.

A policy consists of criteria, action, and scopes.

The criteria are a logical combination of client subnet, server interface IP address, fully qualified domain name (FQDN), Internet Protocol (IPv4/IPv6), transport protocol (UDP/TCP), time of day, and query type.

Specify criteria in the following format:

operator, value01, value02, . . . , operator, value03, value04, . . .

The operator is either EQ or NE. You can specify no more than one of each operator in a criterion.

The policy treats values that follow the EQ operator as multiple assertions which are logically combined (OR'd). The policy treats values that follow the NE operator as multiple assertions which are logically differenced (AND'd).

This cmdlet combines multiple criteria by using the value of the Condition parameter as the logical operator. This parameter takes one of the following values:

• OR. The policy evaluates criteria as multiple assertions which are logically combined (OR'd).
• AND. The policy evaluates criteria as multiple assertions which are logically differenced (AND'd).

If a query meets the criteria of a policy, the action is the response that the policy requires. You can specify ALLOW, DENY, or IGNORE.

If you specify an action of ALLOW in a policy for a server that is authoritative for a query, the policy determines which zone scopes to use to respond to the query and in what ratio. If the answer for the query is cached, the policy determines which cache scopes to use and in what ratio. Otherwise, the policy determines which recursion scope to use.

You can create policies for query resolution at either the server level or the zone level. Server level policies apply on every query that comes to the DNS server. Zone level policies apply only on the queries that can be resolved from a zone hosted on the DNS server. Server level policies apply either on the incoming queries or on the recursive outgoing queries. On the incoming queries, server level policies can only DENY or IGNORE. The most common use for server level policies is to implement blocked or safe lists.

Recursion policies are a special class of server level policies. Recursion policies control how the DNS server performs recursion for a query. Recursion policies apply only when query processing reaches the recursion path. You can chose a value of DENY or IGNORE for recursion for a set of queries. Alternatively, you can choose a set of forwarders for a set of queries. To configure this behavior, specify a recursion scope in the recursion policies. You can use recursion policies to implement a Split-brain DNS configuration. In this configuration, the DNS server performs recursion for a set of clients for a query, while the DNS server does not perform recursion for other clients for that query.

Zone level policies apply to the zone in which you create them. Zone level policies apply only when that zone is found during the query lookup. You cannot create a zone level policy without a zone. If you remove a zone, that removal deletes the associated zone level policies. In a zone level policy, you can specify a value of DENY or IGNORE for a set of queries for records in a zone. Alternatively, if the action is Allow, zone level policies can decide which zone scopes to use to answer queries and in what ratio. One use of such zone level policies is application load balancing by means of DNS.

The DNS server applies server level policies first, except for recursion policies. Then, the DNS server applies zone level policies, and then recursion policies. Each policy has a precedence value. You can specify the precedence by using the ProcessingOrder parameter. The DNS server evaluates queries against policies in the order of precedence for each type of policy.

If the criteria of a server level policy match a query, and if the action is DENY, the DNS server returns SERV_FAIL. If the action is IGNORE, the DNS server drops the query. If the query does not match any server level policy, and if the server is authoritative for the zone for the query, the server evaluates the query with regard to the zone level policies.

If the criteria of a zone level policy in that zone match a query, and if the action is DENY, the server returns SERV_FAIL. If the action is IGNORE, the server drops the query. If the action is ALLOW, the DNS server responds to the query from one of the zone scopes specified in the policy. You can chose to distribute the responses from multiple zone scopes in a particular ratio.

For policy processing, the cache is treated as a zone. The DNS server repeats the process for zone level policies for the cache.

If the server is not authoritative for the zone for which the query has been received, and the response is not found in the cache or the specified cache scope, the DNS server matches the query against the server level recursion policies in order of their precedence. If the criteria of a recursion policy match a query and the action is DENY, the DNS server returns SERV_FAIL. If the action is IGNORE, the DNS server drops the query. If the action is ALLOW, the DNS server gets settings from the configured recursion scope. Based on those settings, the DNS server gets the response for the query by using recursion.

Examples

Example 1: Create traffic management policies

The first two commands create client subnets by using the **Add-DnsServerClientSubnet** cmdlet. The client subnets are for clients in North America and clients in Europe.
PS C:\> Add-DnsServerClientSubnet -Name "NorthAmericaSubnet" -IPv4Subnet "172.21.33.0/24" -PassThru
PS C:\> Add-DnsServerClientSubnet -Name "EuropeSubnet" -IPv4Subnet "172.17.44.0/24" -PassThru
Name                                             IPV4Subnet                                       IPV6Subnet
----                                             ----------                                       ----------
NorthAmericaSubnet                                    {172.21.33.0/24}
EuropeSubnet                                     {172.17.44.0/24}

The next two commands create zone scopes for North America and for Europe by using the **Add-DnsServerZoneScope** cmdlet.
PS C:\> Add-DnsServerZoneScope -ZoneName "Contoso.com" -Name "NorthAmericaZoneScope" -PassThru
PS C:\> Add-DnsServerZoneScope -ZoneName "Contoso.com" -Name "EuropeZoneScope" -PassThru
FileName       : NorthAmericaZoneScope.dns
ZoneName       : contoso.com
ZoneScope      : NorthAmericaZoneScope
PSComputerName : 


FileName       : EuropeZoneScope.dns
ZoneName       : contoso.com
ZoneScope      : EuropeZoneScope
PSComputerName : 

The next two commands add resource records for the zone Contoso.com by using the **Add-DnsServerResourceRecord** cmdlet. The name for both records is the same, career, but the two records point to different addresses. The records also have different scopes. 
PS C:\> Add-DnsServerResourceRecord -ZoneName "Contoso.com" -A -Name "career" -IPv4Address "172.17.97.97" -ZoneScope "EuropeZoneScope -PassThru
PS C:\> Add-DnsServerResourceRecord -ZoneName "Contoso.com" -A -Name "career" -IPv4Address "172.21.21.21" -ZoneScope "NorthAmericaZoneScope" -PassThru
DistinguishedName : career
HostName          : career
RecordClass       : IN
RecordData        : DnsServerResourceRecordA
RecordType        : A
Timestamp         : 
TimeToLive        : 01:00:00
PSComputerName    : 


DistinguishedName : career
HostName          : career
RecordClass       : IN
RecordData        : DnsServerResourceRecordA
RecordType        : A
Timestamp         : 
TimeToLive        : 01:00:00
PSComputerName    :

The final two commands create two policies. The policies allow queries for members of different subnets. The policies differ in scope, so that some clients receive one response to a query, while other clients receive a different response to the same query. 
PS C:\> Add-DnsServerQueryResolutionPolicy -Name "NorthAmericaPolicy" -Action ALLOW -ClientSubnet "eq,NorthAmericaSubnet" -ZoneScope "NorthAmericaZoneScope,1" -ZoneName "Contoso.com" -PassThru
PS C:\> Add-DnsServerQueryResolutionPolicy -Name "EuropePolicy" -Action ALLOW -ClientSubnet "eq,EuropeSubnet" -ZoneScope "EuropeZoneScope,1" -ZoneName contoso.com -PassThru
Action          : Allow
AppliesOn       : QueryProcessing
Condition       : And
Content         : {DnsServerPolicyContent}
Criteria        : {DnsServerPolicyCriteria}
IsEnabled       : True
Level           : Zone
Name            : NorthAmericaPolicy


ProcessingOrder : 1
ZoneName        : contoso.com
PSComputerName  : 


Action          : Allow
AppliesOn       : QueryProcessing
Condition       : And
Content         : {DnsServerPolicyContent}
Criteria        : {DnsServerPolicyCriteria}
IsEnabled       : True
Level           : Zone
Name            : EuropePolicy
ProcessingOrder : 2
ZoneName        : contoso.com
PSComputerName  :

This example shows how to create traffic management policies to direct the customers from a certain subnet to a North American datacenter and from another subnet to a European datacenter.

Example 2: Allow queries for a zone

PS C:\> Add-DnsServerQueryResolutionPolicy -Name "LBPolicy" -ZoneName "contoso.com" -Action ALLOW -FQDN "EQ,career.contoso.com" -ZoneScope "NorthAmericaZoneScope,7;EuropeZoneScope,3" -PassThru
Name                                               ProcessingOrder                                    IsEnabled                                         Action
----                                               ---------------                                    ---------                                         ------
LBPolicy                                           3                                                  True                                              Allow

This command creates a policy named LBPolicy to allow queries for the contoso.com zone. The policy includes two weighted zone scopes.

Example 3: Add policies from one server to another

PS C:\> $Policies = Get-DnsServerQueryResolutionPolicy -ComputerName "Server01"
PS C:\> $Policies | Add-DnsServerQueryResolutionPolicy -ComputerName "Server07" -ThrottleLimit 1

The first command gets all the server level policies on the DNS server named Server01, and then stores the properties in the $Policies variable.

The second command adds the policies stored in $Policies to a different DNS server. This command specifies a value of one (1) for the ThrottleLimit parameter. This value maintains the order of processing policies in the pipeline.

Example 4: Block queries for a domain

PS C:\> Add-DnsServerQueryResolutionPolicy -Name "BlackholePolicy" -Action IGNORE -FQDN "EQ,*.contoso.com" -PassThru | Format-List *
Action                : Ignore
AppliesOn             : QueryProcessing
Condition             : And
Content               : 
Criteria              : {DnsServerPolicyCriteria}
IsEnabled             : True
Level                 : Server
Name                  : BlackholePolicy
ProcessingOrder       : 1
ZoneName              : 
PSComputerName        : 
CimClass              : root/Microsoft/Windows/DNS:DnsServerPolicy
CimInstanceProperties : {Action, AppliesOn, Condition, Content...} 
CimSystemProperties   : Microsoft.Management.Infrastructure.CimSystemProperties

This command creates a policy that blocks queries from a particular domain. The command uses the Format-List cmdlet to control the appearance of the output. For more information, type Get-Help Format-List .

Example 5: Block queries from a subnet

PS C:\> Add-DnsServerClientSubnet -Name "MaliciousSubnet06" -IPv4Subnet 172.0.33.0/24 -PassThru
PS C:\> Add-DnsServerQueryResolutionPolicy -Name "BlackholePolicyMalicious06" -Action IGNORE -ClientSubnet  "EQ,MaliciousSubnet06" -PassThru | Format-List *
Action                : Ignore
AppliesOn             : QueryProcessing
Condition             : And
Content               : 
Criteria              : {DnsServerPolicyCriteria}
IsEnabled             : True
Level                 : Server
Name                  : BlackholePolicyMalicious
ProcessingOrder       : 2
ZoneName              : 
PSComputerName        : 
CimClass              : root/Microsoft/Windows/DNS:DnsServerPolicy
CimInstanceProperties : {Action, AppliesOn, Condition, Content...} 
CimSystemProperties   : Microsoft.Management.Infrastructure.CimSystemProperties

The first command creates a client subnet named MaliciousSubnet06.

The second command creates a policy to block queries from the subnet named MaliciousSubnet06. The policy takes an action of IGNORE, which drops those queries.

Example 6: Block a type of query

PS C:\> Add-DnsServerQueryResolutionPolicy -Name "BlackholePolicyQType" -Action IGNORE -QType "EQ,ANY" -PassThru | Format-List *
Action                : Ignore
AppliesOn             : QueryProcessing
Condition             : And
Content               : 
Criteria              : {DnsServerPolicyCriteria}
IsEnabled             : True
Level                 : Server
Name                  : BlackholePolicyQType
ProcessingOrder       : 3
ZoneName              : 
PSComputerName        : 
CimClass              : root/Microsoft/Windows/DNS:DnsServerPolicy
CimInstanceProperties : {Action, AppliesOn, Condition, Content...} 
CimSystemProperties   : Microsoft.Management.Infrastructure.CimSystemProperties

This command creates a policy to block queries for a particular query type. The policy drops ANY query.

Example 7: Allow recursion for internal clients

PS C:\> Add-DnsServerRecursionScope -Name "InternalClients" -EnableRecursion $True
PS C:\> Set-DnsServerRecursionScope -Name . -EnableRecursion $False 
PS C:\> Add-DnsServerQueryResolutionPolicy -Name "SplitBrainPolicy" -Action ALLOW -ApplyOnRecursion -RecursionScope "InternalClients" -ServerInterfaceIP  "EQ,10.0.0.34" -PassThru 
Action          : Allow
AppliesOn       : Recursion
Condition       : And
Content         : {DnsServerPolicyContent}
Criteria        : {DnsServerPolicyCriteria}
IsEnabled       : True
Level           : Server
Name            : SplitBrainPolicy
ProcessingOrder : 1
ZoneName        : 
PSComputerName  :

The first command creates a recursion scope called InternalClients. Recursion is enabled for this scope.

The second command modifies the default recursion scope by using the Set-DnsServerRecursionScope cmdlet. The default scope, identified by a dot (.), has recursion disabled.

The final command creates a policy that uses the InternalClients scope. For that scope, on the specified server interface address, the policy allows recursion.

Required Parameters

Optional Parameters

Outputs

Microsoft.Management.Infrastructure.CimInstance#DnsServerPolicy

Related Links

• Get-DnsServerQueryResolutionPolicy
• Remove-DnsServerQueryResolutionPolicy
• Set-DnsServerQueryResolutionPolicy
• Add-DnsServerClientSubnet
• Add-DnsServerZoneScope
• Add-DnsServerResourceRecord
• Set-DnsServerRecursionScope
• Add-DnsServerZoneTransferPolicy