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Lesson 1: Understanding Shared Folders

You use shared folders to provide network users with access to file resources. When a folder is shared, users can connect to the folder over the network and gain access to the files that it contains. However, to gain access to the files, users must have permissions to access the shared folders.

After this lesson, you will be able to

• Use shared folders to provide access to network resources.
• Describe how permissions affect access to shared folders.

Estimated lesson time: 15 minutes

Shared Folder Permissions

A shared folder can contain applications, data, or a user's personal data, called a home folder. Each type of data requires different shared folder permissions.

The following are characteristics of shared folder permissions:

• Shared folder permissions apply to folders, not individual files. Since you can apply shared folder permissions only to the entire shared folder, and not to individual files or subfolders in the shared folder, shared folder permissions provide less detailed security than NTFS permissions.
• Shared folder permissions don't restrict access to users who gain access to the folder at the computer where the folder is stored. They apply only to users who connect to the folder over the network.
• Shared folder permissions are the only way to secure network resources on a FAT volume. NTFS permissions aren't available on FAT volumes.
• The default shared folder permission is Full Control, and it is assigned to the Everyone group when you share the folder.

NOTE

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A shared folder appears in Windows Explorer as an icon of a hand holding the shared folder. (Figure 15.1 shows the sharing icon.)

To control how users gain access to a shared folder, you assign shared folder
permissions.

Table 15.1 explains what each of the shared folder permissions allows a user to do. The permissions are presented from most restrictive to least restrictive.

Figure 15.1 Shared folders in Windows Explorer

Table 15.1 Shared Folder Permissions

You can allow or deny shared folder permissions. Generally, it is best to allow permissions and to assign permissions to a group rather than to individual users. You deny permissions only when it is necessary to override permissions that are otherwise applied. In most cases, you should deny permissions only when it is necessary to deny permission to a specific user who belongs to a group to which you have given the permission. If you deny a shared folder permission to a user, the user won't have that permission. For example, to deny all access to a shared folder, deny the Full Control permission.

How Shared Folder Permissions Are Applied

Applying shared permissions to user accounts and groups affects access to a shared folder. Denying permission takes precedence over the permissions that you allow. The following list describes the effects of applying permissions.

• Multiple Permissions Combine. A user can be a member of multiple groups, each with different permissions that provide different levels of access to a shared folder. When you assign permission to a user for a shared folder, and that user is a member of a group to which you assigned a different permission, the user's effective permissions are the combination of the user and group permissions. For example, if a user has Read permission and is a member of a group with Change permission, the user's effective permission is Change, which includes Read.
• Denying Permissions Overrides Other Permissions. Denied permissions take precedence over any permissions that you otherwise allow for user accounts and groups. If you deny a shared folder permission to a user, the user won't have that permission, even if you allow the permission for a group of which the user is a member.
• NTFS Permissions Are Required on NTFS Volumes. Shared folder permissions are sufficient to gain
  access to files and folders on a FAT volume but not on an NTFS volume. On a FAT volume, users can gain access to a shared folder for which they have permissions, as well as all of the folder's contents. When users gain access to a shared folder on an NTFS volume, they need the shared folder permission and also the appropriate NTFS permissions for each file and folder to which they gain access.
• Copied or Moved Shared Folders Are No Longer Shared. When you copy a shared folder, the original shared folder is still shared, but the copy is not shared. When you move a shared folder, it is no longer shared.

The following list provides some general guidelines for managing your shared folders and assigning shared folder permissions:

• Determine which groups need access to each resource and the level of access that they require.
  Document the groups and their permissions for each resource.
• Assign permissions to groups instead of user accounts to simplify access administration.
• Assign to a resource the most restrictive permissions that still allow users to perform required tasks. For example, if users need only to read information in a folder, and they will never delete or create files, assign the Read permission.
• Organize resources so that folders with the same security requirements are located within a folder. For example, if users require Read permission for several application folders, store the application folders within the same folder. Then share this folder instead of sharing each individual application folder.
• Use intuitive share names so that users can easily recognize and locate
  resources. For example, for the Application folder, use Apps for the share name. You should also use share names that all client operating systems can use.

Although Windows 2000 allows for very long share names, try to keep share names short, about 12 characters. Shorter names are easier to remember and type. Products such as MS-DOS, Windows 3.x, and Windows for Workgroups require an 8.3-character share name.

Microsoft Windows 2000 provides 8.3-character equivalent names, but the resulting names might not be intuitive to users. For example, a Windows 2000 folder named Accountants Database would appear as Account~1 on client computers running MS-DOS, Windows 3.x, and Windows for Workgroups.

Practice: Applied Permissions

In the following practice, User101 has been assigned permissions to gain access to resources as an individual and as a member of a group, as shown in Figure 15.2. Determine which effective permissions User101 has in each situation:

1. User101 is a member of Group1, Group2, and Group3. Group1 has Read permission and Group3 has Full Control permission for FolderA. Group2 has no permissions assigned for FolderA. What are User101's effective permissions for FolderA?

Answer

2. User101 is also a member of the Sales group, which has the Read permission for FolderB. User101 has been denied the shared folder permission Full Control for FolderB as an individual user. What are User101's effective permissions for FolderB?

Answer

Figure 15.2 Applied permissions

Lesson Summary

In this lesson, you learned that you can make a folder and its contents available to other users over the network by sharing the folder. Using shared folder permissions is the only way to secure file resources on FAT volumes. Shared folder permissions apply to folders, not individual files. Shared folder permissions don't restrict access to users who gain access to the folder at the computer where the folder is stored. Shared folder permissions apply only to users who connect to the folder over the network.

You also learned about the three shared folder permissions: Read, Change,
and Full Control. The Read permission allows users to display folder names, filenames, file data, and attributes. The Read permission also allows users to
run program files and to change folders within the shared folder. The Change permission allows users to create folders, add files to folders, change data in files, append data to files, change file attributes, and delete folders and files, plus it allows the user to perform actions permitted by the Read permission. The Full Control permission allows users to change file permissions, take ownership of files, and perform all tasks permitted by the Change permission. The default shared folder permission is Full Control, and it is assigned to the Everyone group when you share the folder.