Error: "The request failed with HTTP status 401: Unauthorized." with new ITMS installation

Products

Client Management Suite IT Management Suite

Issue/Introduction

When performing a new installation on a new Notification Server using the Symantec Installation Manager (SIM), the initial configuration fails during the "Pre-configuring" stage with the following error:

A critical error occurred: The request failed with HTTP status 401: Unauthorized. Configuration failed while attempting: Pre-configuring...

The SIM logs show these entries:

Entry 1:
Configuring task 6 of 79: Pre-Configuring ...

----------------------------------------------------------------------------
Date: 3/25/2020 1:48:43 PM, Tick Count: 137142062 (1.14:05:42.0620000), Size: 340 B
Process: SymantecInstallationManager (15772), Thread ID: 13, Module: SymantecInstallationManager.exe
Priority: 4, Source: Symantec.Installation.Automation.Output.ReportInfo

Entry 2:
ConfigureNS - task_Completed(): Configuration Task Pre-Configuring ...
Failed: The request failed with HTTP status 401: Unauthorized.
The request failed with HTTP status 401: Unauthorized.
[System.Net.WebException @ System.Web.Services]
at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
at System.Web.Services.Protocols.SoapHttpClientProtocol.EndInvoke(IAsyncResult asyncResult)
at Symantec.Installation.NSConfiguration.Tasks.AsyncTask.EndAsync(IAsyncResult result)

----------------------------------------------------------------------------
Date: 3/25/2020 1:49:25 PM, Tick Count: 137184062 (1.14:06:24.0620000), Size: 4.25 KB
Process: SymantecInstallationManager (15772), Thread ID: 10, Module: SymantecInstallationManager.exe
Priority: 1, Source: Symantec.Installation.ConfigureNS.task_Completed

While looking further at this, the following entries were found in the Security Event logs and IIS logs every time a reconfigure was tried:

Security log entry:

Log Name: Security
Source: Microsoft-Windows-Security-Auditing
Date: 3/25/2020 2:21:15 PM
Event ID: 4625
Task Category: Logon
Level: Information
Keywords: Audit Failure
User: N/A
Computer: SMPServer.example.com
Description:
An account failed to log on.

Subject:
Security ID: NULL SID
Account Name: -
Account Domain: -
Logon ID: 0x0

Logon Type: 3

Account For Which Logon Failed:
Security ID: NULL SID
Account Name: APP_EXAMPLE_PROD
Account Domain: one

Failure Information:
Failure Reason: An Error occured during Logon.
Status: 0xC000006D
Sub Status: 0x0

Process Information:
Caller Process ID: 0x0
Caller Process Name: -

Network Information:
Workstation Name: SMPServer
Source Network Address: 172.xx.xxx.xxx
Source Port: 54563

Detailed Authentication Information:
Logon Process:
Authentication Package: NTLM
Transited Services: -
Package Name (NTLM only): -
Key Length: 0

This event is generated when a logon request fails. It is generated on the computer where access was attempted.

The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe.

The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network).

The Process Information fields indicate which account and process on the system requested the logon.

The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.

The authentication information fields provide detailed information about this specific logon request.

The Transited services indicate which intermediate services have participated in this logon request.

The Package name indicates which sub-protocol was used among the NTLM protocols.

The Key length indicates the length of the generated session key. This will be 0 if no session key was requested.

Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">;
<System>
<Provider Name="Microsoft-Windows-Security-Auditing" Guid="{xxxxxxxxx}" />
<EventID>4625</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>12544</Task>
<Opcode>0</Opcode>
<Keywords>0x8010000000000000</Keywords>
<TimeCreated SystemTime="2020-03-25T18:21:15.497565900Z" />
<EventRecordID>48305</EventRecordID>
<Correlation ActivityID="{501E5A8B-018E-0019-8C5A-1E508E01D601}" />
<Execution ProcessID="868" ThreadID="9632" />
<Channel>Security</Channel>
<Computer>SMPServer.example.com</Computer>
<Security />
</System>
....
</Event>

IIS Logs:

Status Code: 401 2 5 (Unauthorized)
URI: /Altiris/NS/Services/NSConfigurationWebService.asmx

Environment

ITMS 8.x

Cause

Environment Configuration. This issue typically occurs in environments with specific network configurations that trigger a Windows Loopback Check security restriction. Factors include:

Dual NIC Configuration: Servers with two Network Interface Cards (NICs) sharing a single IP address.
DNS Resolution: Conflicts in validating the proper server name against the assigned hostname.
Loopback Security: Windows prevents authenticated access to a local website using a Fully Qualified Domain Name (FQDN) or CNAME if it does not match the local computer name.

Resolution

After looking online for references in that Security event log entry and IIS logs 401.1 entry, you may see:

Failure Information:
Failure Reason: An Error occured during Logon.
Status: 0xC000006D

and getting a 401.1 on an asmx page.

To resolve this issue, add the server hostnames to the BackConnectionHostNames registry key to bypass the loopback check.

Registry Modification

This command will make changes to your system. Review it carefully before running.

Navigate to the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
Right-click MSV1_0, point to New, and click Multi-String Value.
Type BackConnectionHostNames and press Enter.
Right-click the new value, click Modify, and enter the hostnames for the local site (e.g., the FQDN and local NetBIOS name of the Notification Server).
Click OK and restart the IIS Admin Service or the server.

The following articles have information on the regkey called "BackConnectionHostNames" which when added allows you finish the SMP Server installation:

A quick guide to configuring the Loopback check

System.Net.HttpWebRequest 401 caused by LoopbackCheck

Add BackConnectionHostNames using PowerShell