When working with Active Directory-integrated DNS zones, you might encounter a puzzling scenario where:

C:\Users\User>nslookup hostname  
Server: unknown  
Address: 192.168.1.26

*** Unknown can't find hostname: Non-Existent domain

Yet ping works perfectly:

C:\Users\User>ping hostname

Pinging hostname.domain.com [192.168.1.28] with 32 bytest of data:  
Reply from 192.168.1.28: bytes=32 time=14ms TTL=128

The core issue stems from how nslookup and ping handle DNS queries differently. Ping uses the full DNS resolution process including:

• Appending DNS suffixes from network adapter settings
• Checking local host files
• Following the full DNS resolution chain

Whereas nslookup by default performs a pure DNS query without suffix appending.

For a workgroup client to properly resolve AD DNS names:

1. Network Adapter Settings:
   - Primary DNS: Your AD DNS server (192.168.1.26)
   - Secondary DNS: Another DC if available
   - DNS suffix for this connection: domain.com
   - ✔ Register this connection's addresses in DNS
   - ✔ Use this connection's DNS suffix in DNS registration

2. DNS Server:
   - Forward lookup zone for domain.com exists
   - Allow secure and non-secure dynamic updates
   - Reverse lookup zone exists for your subnet

Check DNS client configuration:

Get-DnsClient | Select-Object InterfaceAlias, ConnectionSpecificSuffix, 
RegisterThisConnectionsAddress, UseSuffixWhenRegistering

Verify DNS registration:

Resolve-DnsName hostname.domain.com -Server 192.168.1.26

The solution often lies in DHCP configuration. AD-integrated networks should:

• Use Windows Server DHCP role instead of router DHCP
• Configure DHCP Option 015 (DNS Domain Name) with domain.com
• Set DHCP Option 006 (DNS Servers) with AD DNS server IPs

Sample DHCP scope configuration in PowerShell:

Add-DhcpServerv4Scope -Name "MainScope" -StartRange 192.168.1.100 
-EndRange 192.168.1.200 -SubnetMask 255.255.255.0
Set-DhcpServerv4OptionValue -DnsDomain domain.com -DnsServer 192.168.1.26

For non-domain joined machines, verify these registry settings:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
- SearchList = domain.com (REG_SZ)
- Domain = domain.com (REG_SZ)
- UseDomainNameDevolution = 1 (REG_DWORD)

For quick testing, you can force nslookup to append suffixes:

nslookup hostname.domain.com
nslookup hostname domain.com

To confirm everything is working properly:

1. Clear DNS cache: ipconfig /flushdns
2. Register DNS: ipconfig /registerdns
3. Check all DNS records exist in the zone

A properly configured system should return consistent results across all resolution methods.

During my recent Active Directory DNS configuration, I encountered an interesting discrepancy between nslookup and ping commands when resolving hostnames from a workgroup client:

C:\Users\User>nslookup hostname
Server: unknown  
Address: 192.168.1.26
*** Unknown can't find hostname: Non-Existent domain

C:\Users\User>ping hostname
Pinging hostname.domain.com [192.168.1.28] with 32 bytes of data:
Reply from 192.168.1.28: bytes=32 time=14ms TTL=128

The difference occurs because:

• Ping uses the full DNS resolution process including DNS suffix search lists
• NSLookup performs a more strict DNS query without suffix appending by default

After extensive testing, these settings proved crucial:

# Network Interface DNS Settings:
Primary DNS: 192.168.1.26 (DC)
DNS suffix for this connection: domain.com
[x] Register this connection's address in DNS
[x] Use this connection's DNS suffix in DNS registration

The critical breakthrough came when I migrated DHCP services from my router to the Windows Server:

# DHCP Scope Options Configuration:
006 DNS Servers = 192.168.1.26
015 DNS Domain Name = domain.com

This script helps validate DNS registration status:

# Check DNS registration status
$computer = $env:COMPUTERNAME
$dnsServer = "192.168.1.26"
$zone = "domain.com"

$record = Get-DnsServerResourceRecord -ZoneName $zone -Name $computer -ComputerName $dnsServer -RRType "A"
if ($record) {
    Write-Host "DNS A record exists:" $record.RecordData.IPv4Address
} else {
    Write-Warning "No DNS record found for $computer.$zone"
}

# Verify DNS suffix search list
Get-DnsClientGlobalSetting | Select-Object SuffixSearchList

When the basic configuration doesn't resolve the issue:

1. Verify reverse lookup zones exist for all subnets
2. Check secure DNS updates are properly configured in AD-integrated zones
3. Test with FQDN in nslookup: nslookup hostname.domain.com
4. Clear DNS client cache: ipconfig /flushdns

To make nslookup behave like ping for name resolution, use these commands:

nslookup
> set srchlist=domain.com
> set search
> hostname

Or alternatively in one line:

nslookup hostname.domain.com