connectivity issue

Question

I am currently running Exchange Server 2016 and have upgraded to Exchange Server 2019 in my lab environment as part of the upgrade process. I plan to move to the Exchange subscription model after the upgrade.

My existing environment consists of two Exchange 2016 servers (Server01 and Server02). I have provisioned two new Exchange 2019 servers (Server03 and Server04).

Inbound mail traffic is routed through a third-party load balancer. My virtual directory URLs start with https://mail.contoso.com/. In the load balancer, I have a pool where the Exchange 2016 servers are added to listen on port 443.

When I add the Exchange 2019 servers to the pool, the load balancer shows that port 443 is not listening on Exchange 2019. When I remove the Exchange 2016 servers and try to access ECP using https://mail.contoso.com/ecp, it doesn’t work. However, when I add back the Exchange 2016 servers, it works fine.

I have configured the virtual directories correctly. Please guide me on how to fix this issue.

Answer 1

Hi Roger Roger 

Thanks for reaching out to the Microsoft Q&A forum. 

I understand how inconvenient and frustrating it can be when your load balancer shows that port 443 is not listening on Exchange 2019, while Exchange 2016 works perfectly. 

Pinpointing the exact cause of this issue can be complex, especially with a third-party load balancer as you've mentioned. As a Microsoft forum moderator, I unfortunately lack the resources to replicate your specific configuration and find an exact solution. However, driven by our mission to provide the best possible assistance, I've invested time in researching some steps you can take to identify the root cause and hopefully resolve your issue. 

Here are some areas to investigate: 

1. Verify exchange 2019 server health status:  

You can gather information about the health status of a specific server using Get-ServerHealth in ExchangePowerShell. For more details, please refer to: Get-ServerHealth (ExchangePowerShell) | Microsoft Learn 

To test whether all the Microsoft Windows services that Exchange requires on a server have started, you can use Test-ServiceHealth. More information is available here: Test-ServiceHealth (ExchangePowerShell) | Microsoft Learn 
2. Validate SSL Certificate Configuration 

Please verify that you have successfully imported (installed) a certificate on your Exchange 2019 server. You can find procedures for this in the following link: 

https://learn.microsoft.com/en-us/exchange/architecture/client-access/import-certificates#how-do-you-know-this-worked 
3. Windows Firewall Configuration: 

It's crucial to check the Windows Firewall on your Exchange 2019 servers to ensure it's not blocking inbound connections on port 443. You can follow this article to access the Windows Firewall with Advanced Security console: 

https://learn.microsoft.com/en-us/windows/security/operating-system-security/network-security/windows-firewall/configure#access-the-windows-firewall-with-advanced-security-console 

4. Double-check the configuration of your third-party load balancer.  

5. Restart IIS (Consider Potential Errors) 
If you've checked the above steps and the issue persists, you could consider restarting the IIS server. You can do this by running: iisreset /noforce 

Please be aware that this command could encounter some errors. If an error appears when running iisreset, here is a Microsoft article that provides a workaround: Error when you use IISReset.exe to restart IIS - Internet Information Services | Microsoft Learn 

I sincerely hope this information helps you clarify and identify the root cause of your issue. If I have misunderstood anything, or if you have any updates or additional information, please don't hesitate to share. Your feedback is invaluable in helping me find the best solution for you. 

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