How to Secure SharePoint 2019 Central Administration site to FQDN using SSL Certificate?

Please see below example steps to Implement it :

OLD AAM details:

Old IIS bindings:

Now Assign new values : https://SP2019Dev-CA.amtest.local:2019

Step 2: Assign SSL certificate binding to the Central Admin Web application Import your SSL certificate to IIS: After getting the certificate from either from your internal CA or from public CA authority, Import the certificate through >> IIS >> Server Certifications >> Import Bind the SSL Certificate with Central Admin Site: As a next step, You'll assign the SSL certificate to the SharePoint Central Administration site. Please note, if you do run Central Admin on more than one server, you'll need to assign the SSL certificate to the web site on each machine.

· Open IIS Manager (Start >> Run >> Type "InetMgr")

· Navigate to SharePoint Central Administration v4 >> Click on "Bindings…" from the right hand panel.

· On the Bindings dialog, click on Edit…

· In the Edit Site Binding dialog, select https from the Type dropdown, leave the IP address as All Unassigned, the Port should say 443. Enter the Host name as cadmin.crescent.com, Select your certificate you imported earlier. Click OK

Step 3: Verify the Alternate Access Mappings When you set the SharePoint central admin to use SSL, SharePoint 2019 automatically modifies the default AAM to point to the new HTTPS URL. E.g. from http://ca.crescent.com to the https://ca.crescent.com. You can verify it once:

· Go to: SharePoint 2019 Central Administration >> Click On Application Management

· Click on "Configure alternate access mappings"

· Click on "Edit Public URLs" >> Pick the SharePoint Central Administration web application >> The default URL should be: https://ca.crescent.com

In case, Central Admin is not accessible, You can add new URL to the AAM binding. Run this PowerShell cmd

New-SPAlternateUrl -WebApplication https://ruhdcdvspwfe01:2019 -Url "https://SP2019Dev-CA.amtest.local:2019" -Zone Default

Once we complete all above steps then you can see new URL for SharePoint Central admin site as per below screenshot.

Please check below three blog series related to SharePoint Central Admin High Availability Secure site on Custom port i.e. 443:

1. Convert SharePoint CA site to FQDN SSL

2. Convert SharePoint CA site port from 2019 to 443

3. Central Administration site High Availability