Unable to add a SMP or Site Server to an Internet Gateway: The remote server returned an error: (403) Forbidden.. HTTP error: Forbidden.

Products

• IT Management Suite
• IT Management Suite

Issue/Introduction

Cannot add his SMP and Site server to Internet Gateway.
The following error appears

Web exception occurred during Server certificate request 
The remote server returned an error: (403) Forbidden.. HTTP error: Forbidden.

The Gateway logs showed the following entries:

Entry 1:

Trying to refresh CRLs for server 'https://smpserver-01.example.com:4726'...
-----------------------------------------------------------------------------------------------------
Date: 6/1/2020 3:34:16 PM, Tick Count: 0 (00:00:00), Size: 319 B
Process: InternetGatewayManager (4708), Thread ID: 14, Module: InternetGatewayManager.exe


Entry 2:
Web certificate request failed - Certificate is not configured on server side.
   at InternetGtwMngrCore.Certificates.ServerDetails.GetServerWebCertificateData()
-----------------------------------------------------------------------------------------------------
Date: 6/1/2020 3:34:16 PM, Tick Count: 0 (00:00:00), Size: 405 B
Process: InternetGatewayManager (4708), Thread ID: 14, Module: InternetGatewayManager.exe

Entry 3:
Failed to validate server certificate.
-----------------------------------------------------------------------------------------------------
Date: 6/1/2020 3:34:16 PM, Tick Count: 0 (00:00:00), Size: 282 B
Process: InternetGatewayManager (4708), Thread ID: 14, Module: InternetGatewayManager.exe

Entry 4:
Trying to get Server certificate. Request: https://smpserver-01.example.com:4726/Altiris/NS/Agent/GetServerCertificate.aspx?CRL=False&Version=8.5.4249.0&Guid=f99b0fa5-beb7-4f14-94b1-26d5d3ce6c65
-----------------------------------------------------------------------------------------------------
Date: 6/1/2020 3:34:16 PM, Tick Count: 0 (00:00:00), Size: 437 B
Process: InternetGatewayManager (4708), Thread ID: 14, Module: InternetGatewayManager.exe

Entry 5:
Web exception occurred during Server certificate request - The remote server returned an error: (403) Forbidden.. HTTP error: Forbidden.
-----------------------------------------------------------------------------------------------------
Date: 6/1/2020 3:34:16 PM, Tick Count: 0 (00:00:00), Size: 380 B
Process: InternetGatewayManager (4708), Thread ID: 14, Module: InternetGatewayManager.exe

Environment

ITMS 8.5

Cause

We found out that he had a proxy server configuration on his internet options for Internet Explorer.

Resolution

Make sure the Proxy server option on the internet browser is disabled or add an exception to the proxy rules to be able to reach out to this page:

https://smpserver-01.example.com:4726/altiris/NS/Agent/GetClientCertificate.aspx