Wednesday 21 October 2015

Folder Permissions: How To Properly Disinherit Permissions

We run into a lot of ACL corruption issues and access issues when a folder has not been disinherited properly.

The following is the best method for disinheriting permissions a folder receives from its parent:

  1. Right click on the folder and click Properties
  2. Click the Advanced button
  3. Click the Change Permissions button if required
  4. Click the Disable inheritance button
  5. Click the Convert inherited permissions into explicit permissions on this object.
    • image
  6. Click on DOMAIN\Domain Users or MACHINE\Users and then the Remove button
    • This removes access to that folder to all domain users
  7. Add the necessary security groups and give them MOD
  8. OPTION: On existing folder sets one can click Replace all child object permission entries with inheritable permission entries from this object
    • Does one want to click this? If there are customized permissions _below_ the folder being disinherited those permissions would be lost.
  9. Click Apply and OK.

From there our folder would now have the necessary permissions for users in the specific security group(s) to make changes.

We enable Access-based Enumeration on _all_ shares we deploy by default. This means that users that are not in the above assigned security group(s) will not see the folder in their File Explorer.

One of the warning signs that the above process was not followed will be for domain admin or local admin accounts to get a UAC prompt when navigating the physical folder set.

As a rule we follow a trunk –> branch –> leaf structure for our folders. All users have a single point of entry with some subfolders having their inheritance blocked.

From there we prefer to _not_ disinherit any further down-level folders unless absolutely necessary because that inevitably leads to access issues and/or permissions corruption.

Philip Elder
Microsoft Cluster MVP
Co-Author: SBS 2008 Blueprint Book

Friday 16 October 2015

E-mail NDR: #5.1.1 SMTP; 550 Rejecting for Sender Policy Framework (SPF too many lookups)

One of our clients was having issues sending an e-mail to one of our regional ISP’s e-mail servers.

  • Remote Server returned ‘< #5.1.1 SMTP; 550 Rejecting for Sender Policy Framework>’
    • SPF too many lookups

There was no further information. The specifics came from a very helpful mail technician at the ISP.

So, we started to dig around and came up with the following:

A ticket went through Third Tier’s Help Desk this week that was based on this problem with Dave Shakelford pointing to the following blog post:

So, what does all of this mean?

It means that we need to make sure all of our clients that send mail via an ISP SMTP server, third party sanitation and continuity service, or mail hosting service need to have a correct SPF record in place.

As the JangoMail blog post makes clear, we may have to jump through a few hoops to get it right, but get it right we must as our client’s mail is critical to their business.

Philip Elder
Microsoft Cluster MVP
Co-Author: SBS 2008 Blueprint Book