"Application not found" message when accessing a publish website with custom domain

Products

• Secure Access Cloud

Issue/Introduction

Secure Access Cloud Web Application configured with a custom domain 

Users accessing the published App are seeing the following warning

Using a SAC domain name instead of custom domain works fine

Internal Web server IP address / port is reachable from the SAC Connector

Required DNS records for custom domain changed and confirmed as valid

 

Environment

SAC Web Application

Custom domain and not default SAC generated domain

Cause

Web Application appears to be corrupted

Resolution

Created a new Web Application with the same setup and problem went away

Additional Information

As part of testing, we can spin up a Web server listening on any port with any host on network running Python. In our case, we did the following as part of testing:

a. If you have an internal Linux server, spin up a Python server on that host listening on TCP 8000 with the following syntax

      python -m http.server 8000

b. change your internal Web server IP address to the Python server. Here is an example snippet of the SAC Web Application configuration where the DNS changes are key. Note that the DNS changes can take up to 30 minutes to complete and nslookup can be used to validate that it hits the right SAC IP address.

c. Access the custom domain and see if you can access the page