A recent upgrade to System Center Operations Manager, taking it to the new 2019 release, perhaps combined with an update to the Windows Server management packs, created an interesting issue.
- Server Service File And Printer Sharing Ports Blocked Account
- Server Service File And Printer Sharing Ports Blocked Number
- Server Service File And Printer Sharing Ports Blocked Users
- What Is File And Printer Sharing
- Firewall Port For File Sharing
- Windows File Sharing Ports
On the management server, an alert was triggered about the management server itself:
Server Service File And Printer Sharing Ports Blocked Account
In both Windows 8 and Windows Server 2012 the File and Printer Sharing ports are blocked by default and you will need to open them up for this to work. Solution for Windows 8. You need to open the ports required for File & Print Sharing. This is roughly the same for doing the same on Windows Server 2012 through the UI. To enable access to File and Printer Sharing on computers using the Windows Firewall with Advanced Security (Windows Vista, Windows 7, Windows 8, Windows Server 2008, Windows Server 2012) please follow these instuctions. Edit an existing Group Policy object or create a new one using the Group Policy Management Tool. The firewall ports necessary for file and printer sharing are not open (ports 445 and 139). Computers will not be able to access shared folders and other Server Message Block (SMB)-based network services on this server. Enable File and Printer Sharing to communicate through the computer's firewall.
Resolution State: New
Alert: Server Service: File and Printer Sharing Ports Blocked
Source: SCOM (SMB)
Path: SCOM.fqdn
Last modified by: System
Last modified time: 3/13/2019 2:14:28 PM
Alert description: Either Windows Firewall is disabled or the firewall inbound rules for TCP ports 445 or 139 are disabled.
Alert: Server Service: File and Printer Sharing Ports Blocked
Source: SCOM (SMB)
Path: SCOM.fqdn
Last modified by: System
Last modified time: 3/13/2019 2:14:28 PM
Alert description: Either Windows Firewall is disabled or the firewall inbound rules for TCP ports 445 or 139 are disabled.
Interesting. Did the upgrade to SCOM 2019 or the management pack somehow break Windows File Sharing? And if it did, why hadn’t we noticed more significant issues than just this alert?
Well, no — it looks like this alert is actually earlier from March, but perhaps the alert has re-surfaced, post upgrade, as the monitor re-evaluated. What I was sure about, however, was that the file sharing ports were indeed open and that this alert couldn’t be correct!
Server Service File And Printer Sharing Ports Blocked Number
Right? Right?
To the Firewall!
Investigating all the relevant firewall rules revealed that everything was in order — Windows File and Printer Sharing exceptions were allowed, as appropriate, across the board.
What is it Detecting?
So, it was time to dig a little deeper.
Server Service File And Printer Sharing Ports Blocked Users
I was able to go to the Alert details and click on the Alert Monitor to drill down and find the details of how the monitor was coming to this apparently erroneous conclusion.
I extracted the script and tried running it manually on the server using cscript.
With a few WScript.Echo calls of mine sprinkled in, the relevant part of the VBScript that powered the monitor was as follows:
So, let’s go ahead and run this.
The script also checks to see if any non-hidden shares exist on the server and will only put the monitor in an unhealthy state if at least one exists.
It iterates over all the rules for port 445, decides all the rules are enabled, which would allow access to File Sharing, but then ends up with fwFileSharingPortsEnabled still being false.
This propagates to the ultimate script output of a PropertyBag with the value Disabled under PortStatus.
All the rules are enabled, but the result is that it considers the ports not open for business??
Is this Logic?
It seems to me that there is a logic error here:
Only if the firewall rule is not enabled and the profile matches the current network profile, we consider the port enabled?
Remember that if the rule is not enabled, traffic would be blocked by the Windows Firewall.
It seems that this might be a simple logic error in the management pack. A comment later in the script even states:
‘ Only if regular share exists and port 139/445 are not open will portStatus be returned as “Disabled”
Am I missing something obvious?
I’d Report This…
I cannot figure out where I should report this, if I’m correct in thinking how this should be working. Should I complain on a forum? Is there a System Center Operations Manager support Twitter profile? Product Support?
What Is File And Printer Sharing
An Unorthodox Workaround
Firewall Port For File Sharing
For now, disabling at least one of the rules for port 445 suppresses this alert. For example, if you don’t need or want Remote Event Log Management, you can disable the Remote Event Log Management (NP-In) rule. This script will then return Enabled and the alert will not be fired.