Debugging DirectAccess Client Connection Issues: IPHTTPS Tunnel Established but Authentication Fails


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When troubleshooting DirectAccess connectivity issues, it's crucial to analyze the specific error patterns. In this case, we observe two alternating error states:

netsh interface httpstunnel show interfaces

Interface IPHTTPSInterface (Group Policy)  Parameters
------------------------------------------------------------
Role                       : client
URL                        : https://server.example.com:443/IPHTTPS
Last Error Code            : 0x0
Interface Status           : IPHTTPS interface active

Despite the IPHTTPS tunnel showing as active, the client cycles between:

Status    : Error
Substatus : CouldNotContactDirectAccessServer

and

Status    : Error
Substatus : RemoteNetworkAuthenticationFailure

Since the connection works via mobile but fails on home networks, we need to examine:

  • NAT configuration on the server side
  • Public IP constraints (single IP scenario)
  • Potential MTU issues in home network environments

Start with these PowerShell commands to gather more data:

# Check DirectAccess connection status history
Get-DAConnectionStatus -Detailed | Format-List

# Verify IPHTTPS connectivity
Test-NetConnection -ComputerName <DA_Server> -Port 443

# Check certificate status
Get-ChildItem Cert:\LocalMachine\My | Where-Object {$_.Subject -like "*IPHTTPS*"}

The RemoteNetworkAuthenticationFailure suggests issues with:

  1. Certificate validation
  2. Kerberos constraints (if using AD authentication)
  3. Network Location Server (NLS) accessibility

Verify NLS connectivity with:

Invoke-WebRequest -Uri "https://nls.yourdomain.com" -UseDefaultCredentials

Check these critical event logs on both client and server:

# Client-side
Get-WinEvent -LogName "Microsoft-Windows-DirectAccess-Client/Operational" | 
    Where-Object {$_.LevelDisplayName -eq "Error"} | 
    Format-List -Property TimeCreated,Message

# Server-side
Get-WinEvent -LogName "Microsoft-Windows-RemoteAccess/Operational" -MaxEvents 50 | 
    Where-Object {$_.LevelDisplayName -eq "Error"}

When basic checks don't reveal the issue, perform network captures:

# Client-side capture (run as Administrator)
netsh trace start capture=yes scenario=NetConnection tracefile=C:\temp\DA_capture.etl
# Reproduce the issue
netsh trace stop

# Server-side capture
New-NetEventSession -Name "DA_Debug" -LocalFilePath C:\temp\DA_server.etl
Add-NetEventPacketCaptureProvider -SessionName "DA_Debug"
Start-NetEventSession -Name "DA_Debug"

Based on similar cases, try these solutions:

# 1. Reset IPHTTPS configuration
netsh interface httpstunnel set interface client enable = no
netsh interface httpstunnel set interface client enable = yes

# 2. Clear DNS cache and renew configuration
ipconfig /flushdns
ipconfig /registerdns

# 3. Verify firewall rules for IPHTTPS
Get-NetFirewallRule -DisplayName "DirectAccess*" | 
    Where-Object {$_.Enabled -ne "True"} | 
    Enable-NetFirewallRule

Create a test script to verify certificate chain:

$request = [System.Net.HttpWebRequest]::Create("https://yourda-server.com/IPHTTPS")
try {
    $response = $request.GetResponse()
    $cert = $request.ServicePoint.Certificate
    $chain = New-Object System.Security.Cryptography.X509Certificates.X509Chain
    $chain.Build($cert) | Out-Null
    $chain.ChainStatus | Format-List -Property Status,StatusInformation
} catch {
    Write-Host "Connection failed: $_"
}

When implementing DirectAccess with Windows Server 2012 and Windows 8 Enterprise clients, I encountered a peculiar connectivity pattern:

  • Successful connections through mobile networks
  • Consistent failures when connecting from home networks
  • IPHTTPS tunnel showing as active (confirmed via netsh command)
  • Cyclic error states between CouldNotContactDirectAccessServer and RemoteNetworkAuthenticationFailure
// Sample output showing the connection status cycling:
PS C:\> Get-DAConnectionStatus

Status    : Error
Substatus : CouldNotContactDirectAccessServer

[10 minutes later...]
Status    : Error
Substatus : RemoteNetworkAuthenticationFailure

The server sits behind NAT with a single public IP, making IPHTTPS the only viable protocol. Key configuration points:

// Current IPHTTPS configuration:
netsh interface httpstunnel show interfaces

Interface IPHTTPSInterface (Group Policy)  Parameters
------------------------------------------------------------
Role                       : client
URL                        : https://da.example.com:443/IPHTTPS
Last Error Code            : 0x0
Interface Status           : IPHTTPS interface active

Start with these verification steps:

// 1. Check IPHTTPS connectivity:
Test-NetConnection -ComputerName da.example.com -Port 443

// 2. Verify certificate chain:
$cert = Get-ChildItem -Path Cert:\LocalMachine\My |
        Where-Object {$_.Subject -like "*da.example.com*"}
$cert | fl Subject,Thumbprint,NotAfter,HasPrivateKey

// 3. Examine security event logs:
Get-WinEvent -LogName "Microsoft-Windows-DirectAccess-Client/Operational" -MaxEvents 10 |
Format-List -Property TimeCreated,Id,Message

From experience, these factors often cause similar issues:

Certificate Validation Problems

IPHTTPS requires proper certificate configuration. Verify with:

// Certificate validation script:
$req = [System.Net.HttpWebRequest]::Create("https://da.example.com/IPHTTPS")
try {
    $res = $req.GetResponse()
    $cert = $req.ServicePoint.Certificate
    $chain = New-Object System.Security.Cryptography.X509Certificates.X509Chain
    $chain.Build($cert) | Out-Null
    $chain.ChainStatus | Select-Object Status,StatusInformation
} catch {
    Write-Host "SSL Error: $_" -ForegroundColor Red
}

NAT Configuration Issues

Even with IPHTTPS, certain NAT behaviors can interfere. Check NAT mapping:

// On the DirectAccess server:
Get-NetNat | Select-Object Name,ExternalIPInterfaceAddressPrefix,InternalIPInterfaceAddressPrefix

For persistent issues, enable detailed logging:

// Enable verbose IPHTTPS logging:
netsh trace start scenario=NetConnection capture=yes tracefile=C:\temp\iphttps.etl
netsh interface httpstunnel set tracing level=verbose
// After reproducing the issue:
netsh trace stop

Analyze the resulting ETL file with Network Monitor or Message Analyzer.

Despite ruling out the firewall, verify these critical Windows Firewall rules exist:

// Check DirectAccess client firewall rules:
Get-NetFirewallRule -DisplayName "DirectAccess*" | 
Where-Object {$_.Enabled -eq "True"} |
Select-Object DisplayName,Profile,Direction,Action