How to Check DNS on Windows Server

DNS is the foundation of everything on a Windows Server network — Active Directory, name resolution, internet access, and application connectivity all depend on it working correctly. When something stops working on a server, DNS is often the cause. Here is how to check DNS health and diagnose resolution problems.

Check What DNS Server the Server Is Using

# PowerShell — show DNS servers for all adapters
Get-DnsClientServerAddress | Where-Object {$_.AddressFamily -eq 2} | Select-Object InterfaceAlias, ServerAddresses

# Command Prompt
ipconfig /all | findstr "DNS Servers"

For a domain-joined server, the primary DNS should be the IP address of a domain controller — not 8.8.8.8 or your ISP’s DNS. Using external DNS on a domain-joined server breaks Active Directory lookups.

Test DNS Resolution with nslookup

# Resolve a hostname using the server's configured DNS
nslookup google.com

# Resolve using a specific DNS server
nslookup google.com 8.8.8.8

# Reverse lookup (IP to hostname)
nslookup 192.168.1.10

# Query for a specific record type
nslookup -type=MX contoso.com
nslookup -type=SRV _ldap._tcp.contoso.local

If nslookup google.com returns an IP but nslookup internalserver fails, the server can reach external DNS but internal DNS is broken — pointing to a wrong or unreachable DNS server for internal resolution.

Test DNS with Resolve-DnsName (PowerShell)

# Resolve a hostname
Resolve-DnsName google.com

# Resolve using a specific DNS server
Resolve-DnsName google.com -Server 8.8.8.8

# Resolve internal AD service records
Resolve-DnsName _ldap._tcp.contoso.local -Type SRV

# Test reverse lookup
Resolve-DnsName 192.168.1.10 -Type PTR

Resolve-DnsName is more flexible than nslookup and returns structured objects you can pipe and filter.

Check the Local DNS Cache

Windows caches DNS responses — a stale cache entry can cause connectivity problems even after DNS records are updated:

# View the DNS client cache
Get-DnsClientCache | Select-Object Entry, RecordType, TimeToLive, Data

# Clear the DNS cache
Clear-DnsClientCache

# Command Prompt equivalent
ipconfig /displaydns
ipconfig /flushdns

Flushing the cache forces the next lookup to query the DNS server fresh — useful after changing DNS records or fixing a DNS problem.

Check the DNS Server Service (on a DNS Server)

If the server runs the DNS Server role:

# Check if the DNS service is running
Get-Service DNS

# Restart DNS service
Restart-Service DNS

# View DNS server statistics
Get-DnsServerStatistics

# Check DNS server zones
Get-DnsServerZone

In DNS Manager (dnsmgmt.msc), right-click the server and select Test to run a simple connectivity and resolution test.

Verify Active Directory DNS Records

Active Directory depends on specific SRV records existing in DNS. Run dcdiag /test:dns on a domain controller to run a comprehensive DNS health check specifically for AD:

dcdiag /test:dns /v

This checks that all required AD DNS records (_ldap, _kerberos, _gc) exist and resolve correctly. Any FAILED tests point to missing or incorrect DNS records that need to be registered or fixed.

To force a domain controller to re-register its DNS records:

ipconfig /registerdns
net stop netlogon && net start netlogon

Check DNS Forwarders

A DNS server that cannot resolve external names may have broken forwarders:

# Check configured forwarders
Get-DnsServerForwarder

# Test forwarding manually
nslookup google.com [your-DNS-server-IP]

In DNS Manager: right-click the server → Properties → Forwarders tab. The forwarders should point to your ISP’s DNS or a reliable external resolver (e.g. 8.8.8.8, 1.1.1.1).

Common DNS Problems on Windows Server

• Server using wrong DNS: set primary DNS to domain controller IP, not router or external DNS
• Stale cache entries: run ipconfig /flushdns after any DNS changes
• Missing SRV records: run dcdiag /test:dns and ipconfig /registerdns on DCs
• DNS Server service stopped: Get-Service DNS — restart if stopped
• Zone not replicating: check AD-integrated zone replication scope matches AD replication topology

Related Guides

• How to Check Network Connectivity from Windows Server
• How to Join a Server to a Domain
• How to Check Active Directory Replication Health