Networking / Security · Risk: High · Documentation Verified
Last verified: 2026-10-26
Microsoft DnsServer reference: Modifies cache settings for a DNS server. The syntax and selected example below are adapted from the pinned Windows Server 2025 reference. Module availability, target configuration and delegated permissions determine whether it can run in your environment. Documentation and parameter text: Microsoft, CC BY 4.0; formatting adapted by Cmdlet World. No execution testing is claimed.
Use an account with the target resource permissions documented for Set-DnsServerCache. Modifying administrative cmdlets may require elevation or delegated administration. This catalog does not assert that ordinary users can execute the command.
Supported environments
Windows / DnsServer · Windows Server 2025 documentation; feature/module prerequisites apply
Parameters
-AsJob
Runs the cmdlet as a background job. Use this parameter to run commands that take a long time to complete. The cmdlet immediately returns an object that represents the job and then displays the command prompt. You can continue to work in the session while the job completes. To manage the job, use the *-Job cmdlets. To get the job results, use the Receive-Job cmdlet. For more information about Windows PowerShell background jobs, see about_Jobs.
-CimSession
Runs the cmdlet in a remote session or on a remote computer. Enter a computer name or a session object, such as the output of a New-CimSession or Get-CimSession cmdlet. The default is the current session on the local computer.
-ComputerName
Specifies a DNS server. The acceptable values for this parameter are: an IPv4 address, an IPv6 address, and any other value that resolves to an IP address, such as fully qualified domain name (FQDN), host name, or NETBIOS name.
-Confirm
Prompts you for confirmation before running the cmdlet.
-IgnorePolicies
Indicates whether to ignore policies for this cache.
-LockingPercent
Specifies a percentage of the original Time to Live (TTL) value that caching can consume. Cache locking is configured as a percent value. For example, if the cache locking value is set to 50, the DNS server does not overwrite a cached entry for half of the duration of the TTL. By default, the cache locking percent value is 100. This value means that the DNS server will not overwrite cached entries for the entire duration of the TTL.
-MaxKBSize
Specifies the maximum size, in kilobytes, of the memory cache of a DNS server.
-MaxNegativeTtl
Specifies how long (1 to 2592000 seconds) an entry that records a negative answer to a query remains stored in the DNS cache. The value must be provided as a TimeSpan. The default setting is 15 minutes.
-MaxTtl
Specifies how long (0 to 2592000 seconds) a record is saved in cache. The value must be provided as a TimeSpan. If the TimeSpan is set to 0 seconds, the DNS server does not cache records. The default setting is one day (86,400 seconds).
-PassThru
Returns an object representing the item with which you are working. By default, this cmdlet does not generate any output.
-PollutionProtection
Specifies whether DNS filters name service (NS) resource records that are cached. Valid values are zero, which caches all responses to name queries and is the default value; and one, which caches only the records that belong to the same DNS subtree. When you set this parameter value to False, cache pollution protection is disabled. A DNS server caches the Host (A) record and all queried NS resources that are in the DNS server zone. In this case, DNS can also cache the NS record of an unauthorized DNS server. This event causes name resolution to fail or to be appropriated for subsequent queries in the specified domain. When you set the value for this parameter to True, the DNS server enables cache pollution protection and ignores the Host (A) record. The DNS server performs a cache update query to resolve the address of the NS if the NS is outside the zone of the DNS server. The additional query minimally affects DNS server performance. For more information about DNS cache locking, see DNS Cache Locking. For more information about cache pollution protection, see Securing the DNS Server Service. For more information about NS resource records, see Managing resource records.
-StoreEmptyAuthenticationResponse
Specifies whether a DNS server stores empty authoritative responses in the cache (RFC-2308). The default value is True.
-ThrottleLimit
Specifies the maximum number of concurrent operations that can be established to run the cmdlet. If this parameter is omitted or a value of 0 is entered, then Windows PowerShell® calculates an optimum throttle limit for the cmdlet based on the number of CIM cmdlets that are running on the computer. The throttle limit applies only to the current cmdlet, not to the session or to the computer.
-WhatIf
Shows what would happen if the cmdlet runs. The cmdlet is not run.
Prerequisites
Windows with the DnsServer module and the Windows feature or management tools that provide it. Confirm target connectivity and version compatibility using the linked Microsoft reference.
Security considerations
This cmdlet changes system state. Review every target and parameter in the official reference, test outside production, and prepare an appropriate backup or rollback. Do not execute the example automatically.
Examples
Example 1: Set the maximum cache size on a DNS server
This command sets the maximum cache size to 10,240 KB on a DNS server that has an FQDN of Win12S-05.DNSServer-01.Contoso.com. Source: Microsoft, CC BY 4.0; transcript prompt/output removed. This example was not executed.