When a Custom Domain is configured, and the end-user will authenticate using DSSO, the end-user will land on the default domain.

Example: The user will go to https://Custom_domain.com and they will land on https://subomain.okta.com.

• Desktop Single Sign On (DSSO) 

• Custom Domain

1. Go to the server that is hosting the DSSO agent. 

2. Navigate to C:\inetpub\wwwroot\IWA\web.config

3. Look for <oktaSSOConfigGroup>

4. Modify <oktaSSOConfig orgOktaAuthenticationURL= and orgBackupOktaAuthenticationURL= from the default domain to the custom domain.

Example:

<oktaSSOConfigGroup>
    <oktaSSOConfig orgOktaAuthenticationURL="https://Your_custom_Domain.com/login/sso_iwa_auth"
                      orgBackupOktaAuthenticationURL="https://Your_custom_domain/login/default"
                      oktaSSOWebAppVersion="1.12.3.0">
      <iwaDetection timeout="1000" />
      <upnTransformation>
        <!-- An example how to convert all users from foo.com domain to corresponding users of bar.com domain:
               <rule match="(.+)@foo.com" replace="${1}@bar.com" />
        -->
      </upnTransformation>
    </oktaSSOConfig>

• Once the above is done, restart the IIS server and test it.