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The general process of sharing folders the causes and solutions of file sharing failure

Does different workgroups in    3.1 affect shared files?

   3.2Firewall is not set correctly

   3.3users are disabled

     3.3.1 Guest users are disabled

     3.3.2 other users are disabled

   3.4 users do not have permission to access

   3.5 the local security policy is set incorrectly

The file and printer sharing of the    3.6Nic is not turned on.

The    3.7system uses cached account access from previous connections

   3.8 questions about "Network access: a sharing and Security Model for Local accounts"

   3.9What does the Windows10 system change when it refuses unsafe guests to log in in different places?

   4.1When you right-click a folder to share files

   4.2 set the location in figure 1 to turn off password protected sharing

   4.3 enables additional knowledge of user accounts in the Control Panel

A summary of the options in figure 1 of    5.1.

   5.2View users and hostnames that access shared folders, as well as files accessed

Two ways for    5.3 to access shared folders

Use of    5.4net use

Attribute explanation of    5.5Nic

   5.6 Network Discovery depends on Services and Firewall Ports and setting methods

This article was last updated in 2018-11-27. Update: the content of section 3.9 of this article.

1. The problems to be solved in this article

   in the process of using windows system, we generally share folders mainly using the functions that come with the system. But there are often a lot of problems in the process of sharing. According to the tutorials on the network, some people may have correct access to the shared folder, while others may not. So the main purpose of this article is to analyze and solve the problems related to sharing folders on Windows. In the process of analysis, some file sharing mechanisms and additional knowledge are also explained. The problems are mainly divided into two categories, one is inaccessible, the other is unauthorized access. As there is a lot of content involved in sharing files, it is recommended that you read this article from the beginning and do not skip it, otherwise you may miss some details and fail to share folders successfully. This article has enumerated and analyzed most of the problems related to shared folders, but the problems are always changeable, and other netizens may encounter different problems, so this article will be updated and supplemented from time to time. Or there will be mistakes to make changes.

two。 The general process of sharing folders

   here I will first follow the general method to set up folder sharing, and then explain in detail the meaning of each part of the setting in this article.

The general steps for sharing a folder are:

1. Right-click the folder that needs to be shared, select Properties, and follow the method below.

two。 Open Control Panel\ Network and Internet\ Network and sharing Center\ Advanced sharing Settings. Enable File and Printer sharing and turn off password protected sharing.

You can press win + r to enter control and press OK to open the control panel.

Figure 1

The content in this picture will be used in the explanations and settings elsewhere in this article, please note here.

3. The causes of file sharing failure and the solutions

File sharing fails for the following reasons:

1. Does a different workgroup affect shared files?

two。 The firewall is not set correctly

3. User is disabled

3.1Guest user is disabled

3.2 other users are disabled

4. The user does not have permission to access

5. Local security policy disabled

6. The file and printer sharing of the network card is not turned on.

7. The system uses previously cached account access

Let's start with the analysis one by one.

3.1 does different workgroups affect shared files?

When    is looking for solutions to problems related to shared files, it is often seen in some posts that a workgroup should be set up first so that the hosts of both the shared folder and the access to the shared folder are in the same workgroup. After testing, hosts in different workgroups can also share files normally.

3.2 Firewall is not set correctly

   puts the firewall in the first place here because the problem for most people is that the corresponding port of the firewall is not open. There are two ways to open the corresponding port of the firewall:

1. Check the box on the left side of File and Printer sharing in Control Panel\ system and Security\ Windows Firewall\ allow programs or functions to pass through Windows Firewall. This opens the corresponding shared port in the firewall.

two。 In figure 1, select enable File and Printer sharing in File and Printer sharing.

   actually "enables file and printer sharing" also opens the corresponding sharing port in the firewall. The results of the above two methods are the same. It's just that the setting is different. You can click Advanced Settings in the left column of Control Panel\ system and Security\ Windows Firewall to open the Advanced Security Windows Firewall. Or directly win + r type wf.msc to open it. Click "inbound rules" in the left sidebar, and find "File and Printer sharing" in the middle display. You can see that there are many rules related to "file and printer sharing". View rules related to the current network location. That is, if you are currently on a public network, viewing the profile is a common rule related to File and Printer sharing. Currently under the private network, viewing the "profile" is a dedicated "file and printer sharing" related rules. Set "File and Printer sharing" in the first two locations where the firewall is set, to see what happens to the next few options. It mainly depends on the changes in the "enabled" column.

3.3user is disabled 3.3.1 Guest user is disabled

The more common problem with    is that Guest users are disabled because guest users are disabled by default after the new system is installed. Any operation in the Windows system needs to be done as a user. Access to shared folders is no exception. If you add Everyone or Guest when sharing a folder, the user identity used when accessing over the network defaults to Guest. There are two ways to enable Guest users. The following two methods work in the same way, but in different places.

1. Right-click "my computer" and select "manage". In computer Management\ Local users and groups\ users, right-click Guest users and select Properties. Just uncheck the check box on the left side of "account disabled".

Press "win + r" to type secpol.msc to open Local Security Policy. Open the Guest account in Security Settings\ Local policies\ Security options.

The result of    setting in the above two places is to change the registry. Changes are made by the lsass.exe program. The changed locations are the following 3:

1.HKLM\ SAM\ SAM\ DOMAINS\ Account\ Users\ 000001F5\ F

2.HKLM\ SAM\ SAM\ DOMAINS\ Account\ Users\ 000001F5\ V

3.HKLM\ SAM\ SAM\ DOMAINS\ Account\ F

Where 000001F5 is the unique identifier of the Guest user. Right-click HKLM\ SAM\ SAM and select "permissions" to add user permissions to see the subkey.

   sometimes finds that even if the Guest user is enabled, a dialog box prompts for a user name and password when accessing. This is because all operations under the Windows system need to be run as a user. So you can enter Guest directly without entering a password. However, if you set a password for Guest, you still need to enter a password.

   's question about setting Guest passwords and "password protected sharing" in figure 1. "password protected sharing" is associated with Guest accounts.

   cannot select turn off password protected sharing if you have set a password for Guest users. This appears if you do not enter a password when accessing the shared folder.

   if you choose enable password Protection without setting a password for the Guest user, the Guest user will be disabled and added to the local security policy deny access to this computer from the network. Please see the introduction to local security policies later in the article.

The following error occurs when accessing a shared folder from the network

3.3.2 other users are disabled

   can use not only Guest but also authorized accounts when accessing shared folders. So it is also inaccessible to the shared folder if you use a disabled account.

3.4 users do not have permission to access

   explains that permissions are divided into share permissions and NTFS permissions. Users who want to access shared folders through the network must have NTFS permissions and share permissions. In order to have share permissions, you must first have NTFS permissions. To view the NTFS permissions a user has on this folder, right-click the folder\ Properties\ Security tab to view the permissions owned by individual users and groups. You can also edit the permissions of each user or group individually.

You can right-click the folder\ Properties\ share\ share to view the sharing permissions of each user and group.

Occurs when you use an unauthorized user to access a network shared folder

3.5 incorrect local security policy settings

The    local security policy also affects access to shared folders in several ways. You can press "win + r" or enter secpol.msc in the start menu to open the local security policy, or you can enter "local security policy" directly in the start menu search box to open it.

1.

   as shown in the figure above, if you add a user to deny access to this computer from the network and use that user to access the shared folder, the following error may occur:

two。

   as shown in the figure above, if the above Local Security Policy item is enabled, the following error may occur. After testing, this item is for non-Guest accounts. That is, whether this item is enabled or not has nothing to do with the Guest account. The console login described in the figure refers to local physical login and non-remote network login.

3.6 File and Printer sharing on the Microsoft Network of the Network Card is not opened

   is less likely to encounter this problem, but sometimes unexpected errors can occur here.

   opens Control Panel\ Network and Internet\ Network connections for hosts on the shared folder side, right-click the network card, and select Properties. You can see "File and Printer sharing on the Microsoft Network" under the Network tab. Cancel the check box on the left side of the option, and then enter the check box again and press OK.

   also operates the "Microsoft network client" for hosts accessing the shared folder side.

Every Nic in    has the same settings. Therefore, the setting here is relative to each network card, that is, it can be set that the network devices connected to the network card of the host can access the shared folder, while the network devices connected to other network cards of the host cannot access the shared folder of the host. This has a more flexible configuration for hosts with multiple network cards.

After setting up, you may have to restart the network card or host.

3.7 the system uses account access cached on previous connections

   needs to provide a user name or username and password when accessing the shared folder for the first time. The system automatically remembers the user name and password used when accessing the shared folder after the first successful access. The user name and password are automatically used the next time you access the shared folder. When the host of a shared folder changes settings, such as changing a user's password. At this time, there will be no access rights. As shown in the following figure:

   can delete the user name and password that were saved automatically by the system at this time. You can delete it using the net use command. The usage is to view the current network connection using the net use command first. And then use the

The net use / delete\\ ComputerName command deletes the automatically saved username and password. ComputerName here is the hostname.

If you are accessing the shared folder using an IP address instead of a hostname, enter the IP address here.

   can directly use the net use command to set the username and password used to access a network shared folder. The method to use is "net use\\ IP address password / user: username" or "net use\\ hostname password / user: username"

Note:

Although the IP address and hostname correspond to the same shared host, the IP address and hostname are different when using net use. When "net use\\ IP address 123456 / user:xigege" and "net use\\ hostname 123456 / user:paitouxi" are set, the xigege identity is used when accessing the shared folder with "\\ IP address". If you use "\\ hostname" to access the shared folder, you will use the identity of paitouxi.

   can use the "net use / delete\ WIN-I4BTR51SSDT" command to delete the login credentials used when accessing the shared folder. However, if you do not disconnect all access to the host when using this command, you can continue to access the shared folder using your previous login credentials, so it is best to disconnect all connections to the shared host before executing the command. If you use Windows Explorer to access the share, you need to close it before executing the command. After executing the command, you have to wait a few seconds until the command is executed and open the remote shared folder again to pop up the user login dialog box. You can see the hosts and users you are accessing in the remote shared host (you can learn how to view it in the additional knowledge section).

3.8 questions about "Network access: a sharing and security model for local accounts"

   believes that many friends have come across the setting of this item in online sharing tutorials, which generally requires that it be set to "Classic-authenticate local users without changing their original identity." However, it is also possible to set to Guest only-authenticate the local user as a guest. It's just that after the password-protected sharing is turned off in figure 1, you can use any user to access the shared folder over the network, but the identity is verified as the guest account, that is, Guest. You can use the use net\\ ip address\ user: user name command at the command prompt to set the user to use when accessing the shared folder of a host on the network. It can be found that no matter what the user name is set to, the shared folder can be accessed. However, if you set it in figure 1 to enable password-protected sharing, you can only use administrators or Guest users to access shared folders through the network. You can press win + r in the host of the shared folder to enter compmgmt.msc or right-click "my computer" and choose "manage" to open the "computer Management" console. See which host uses which account to access the shared folder in computer Management\ shared folder\ session. This means that only folders that the Guest user has permission can be accessed over the network. After setting this item, you need to set up the following places in order to share folders correctly:

1. Enable Guest.

two。 Remove Guest users from the local security policy deny access to this computer on the network.

3. Enable File and Printer sharing.

4. Right-click the folder you want to share to add Guest permissions and share.

What    says here is that you can choose whether or not to set a password for Guest. Password protection sharing is automatically enabled if the Guest password is enabled. Some friends may make mistakes when testing this item through the network. If you have read the previous section of this article to confirm that there is no problem, the possible reason is that you used other accounts to access the shared folder over the network. Setting this to Guest only-authenticating local users who are guests will cause access errors. You can delete the previous cache using the net use / delete\ IP address or hostname. Another phenomenon is that sometimes even if the administrator and Guest user password is changed, the client can still access the shared folder without entering the password, and the administrator and Guest user password can be changed multiple times.

   has added a local group policy item since Windows 10, which disables insecure guest login by default, so if the server host sets the item "Guest only-authenticates local users, they are guests", it is inaccessible by default on Windows 10 clients. The following error occurs during access:

The reason for the inaccessibility may not be prompted here, but if you set up the user to access the network shared folder at the command prompt, you will have the following prompt:

You can enter the "Local Group Policy Editor" in the cortana search box to open and enable the following items in the following location, effective immediately after configuration, without the need to log out or restart the computer.

   is worth mentioning that the network folder sharing host setting "Classic-authenticate local users without changing their original identity" when using Guest user identity access in the Windows 10 client does not need to configure "enable insecure guest login". The reason is obvious that when the share is not protected with a password, all users who can access the computer through the network, including anonymous Internet users, can access the shared resources, and the system does not authenticate the user's identity. When it is set to "Classic-authenticate local users without changing their original identity", although the Guest user identity is also used, the identity is clear and different from the former. In other words, the latter can be accessed through the network only if the user exists on the host where the shared folder resides and the shared access permission is set in the shared folder.

3.9 by default, the Windows10 system rejects the login of unsafe guests

   Windows 10 denies unsafe guest logins by default. When accessing a shared folder, the following figure is displayed when accessing if none of the users on the host of the shared folder have set a password:

If you enter the net use\\ ip address on the command line, the cause of the error will be displayed.

There are two solutions to this situation:

Use explicitly specified enabled users to access the shared folder. As shown in the following figure:

II. Revise the reorganization strategy

   press window+ R to enter gpedit.msc to launch the Local Group Policy Editor. Locate the "computer configuration-Administrative templates-Network-Lanman Workstation" node, and find the policy setting of "enable unsafe guest login" in the content area on the right. Double-click the policy setting enable unsafe guest login, change it to enabled, and click the OK button, as shown in the following figure:

   above is what happens when all users in the host of the shared folder do not have a password set to access the shared folder. If any one of the hosts on the shared folder has a password set, this is the same as accessing the shared folder on the Windows 7 system. When you visit, a login dialog box pops up, as shown in the following figure, just enter the correct user name and password.

4. What changes did the system change when it was set up in different places

After the previous analysis,    can know where the shared folder needs to be set up. Now let's analyze what the system does automatically when sharing a folder.

4.1 when you right-click a folder to share files

When    right-click a folder to share a file, the system automatically opens folder and printer sharing, that is, opens the folder and printer sharing firewall port and sets the "folder and printer" option in figure 1 to enable.

4.2 set the location in figure 1 to turn off password protected sharing

When password Protection sharing is turned off, the system automatically sets up 2 places.

1. Enable the Guest account, that is, set the registry as in the previous section "Guest account is disabled", enable the Guest account in the local security policy entry, and enable the account in computer Management.

two。 Remove the Guest account from the deny access to this computer from the network so that Guest users can access the computer over the network.

4.3 enable user accounts in the Control Panel

2 changes were made after the user account was enabled in the control panel.

1. Enable the Guest account.

two。 Delete the Guest account from the deny Local login entry so that Guest users can log in locally.

   can see the difference between the two settings from 4.2 and 4.3. One allows network access and does not allow local login. One allows local login and does not allow network access. Allow local login, that is, you can log in using the Guest user in the boot interface or when switching users.

5. Additional knowledge 5.1 A summary of the options in figure 1.

The role of each option is already explained in figure 1, and only additional instructions are given here.

1. Network discovery

   this option is used to see whether other hosts on the network can see the device in the Network (the previous Network neighbor). If disabled, you cannot see it, but you can still access it directly by entering an ip address in Windows Explorer, such as\ 192.168.25.110, or directly entering the hostname\\ WIN-I4BTR51SSDT\. But entering an ip address for access is faster.

two。 File and printer sharing

   this option turns on file and printer sharing. The smb protocol is used.

3. Public folder sharing

   this option is used to share the public folder, the shared directory is C:\ Users\ Public. Turn this option off so that hosts on the network cannot see or access the shared directory in the Network.

4. Media stream

   is used to build media libraries and share pictures, audio and video. The shared directory here is also C:\ Users\ Public. The DLNA protocol is used. The full name of DLNA is DIGITAL LIVING NETWORK ALLIANCE (Digital Life Network Alliance). The media library can be accessed from another host in the network through Windows media player or a network device that supports DLNA. You can also view the media library in the "Network location" column of windows Explorer. You can see that there are two media devices in the following figure. WIN-WINDOWS-7 is the media playback device. Only media playback devices on the network that support the upnp protocol, such as Windows Media Player, will appear here. WIN-WINDOWS-7:paitouxi: it's a media library. The media playback device is used to play the content in the library.

   for Windows Media Player to appear in the "Network" media device column of other hosts on the network, you must open Windows Media Player and set "automatically allow the device to play my media". In this way, other hosts in the network can right-click pictures, audio and video files and choose to play them to this host. You can also play the content from the media library in the network directly in the other Media Library in the following figure.

5. File sharing connection

   Windows 7 uses 128bit encryption to help protect file sharing connections. Some devices do not support 128-bit encryption and must use 40-or 56-bit encryption.

6. Password protected sharing

   sets whether a password is required when a network host accesses a local shared folder.

5.2 View the users and hostnames that access the shared folder and the files accessed

   sometimes we want to see who is accessing our shared folders and which files are being accessed. At this time, you can use the tools that come with the Windows system to view. Press win + r to enter compmgmt.msc or right-click "my computer" and select "manage" to open the "computer Management" console.

You can see which host uses which account to access the shared folder in computer Management\ shared folder\ session.

You can see which files have been viewed in computer Management\ shared folders\ Open Files.

5.3 two ways to access a shared folder

There are two ways for    to access a shared folder. The first is to view it directly in Network in Windows Explorer. The second is to enter the IP address in the address bar of Windows Explorer, such as\\ 192.168.25.110

5.4 use of net use

The    net use command sets the user and password to use when accessing a shared folder. You can view and disconnect the shared host to which you are currently connected.

Use net use to view the shared host to which you are currently connected.

Use the net use command to set the username and password used to access a network shared folder. The method to use is "net use\\ IP address password / user: username" or "net use\\ hostname password / user: username"

Note:

Although the IP address and hostname correspond to the same shared host, the IP address and hostname are different when using net use. When "net use\\ IP address 123456 / user:xigege" and "net use\\ hostname 123456 / user:paitouxi" are set, the xigege identity is used when accessing the shared folder with "\\ IP address". If you use "\\ hostname" to access the shared folder, you will use the identity of paitouxi.

Use the "net use\\ IP address / delete" or "net use\\ hostname / delete" command to delete the user name and password used when connecting to a host.

You can also use the "net use / delete *" command to enter "Y" to delete all saved usernames and passwords for accessing the shared host.

Note: the login credentials used when accessing the shared folder can be deleted using the "net use / delete\ WIN-I4BTR51SSDT" command. However, if you do not disconnect all access to the host when using this command, you can continue to access the shared folder using your previous login credentials, so it is best to disconnect all connections to the shared host before executing the command. If you use Windows Explorer to access the share, you need to close it before executing the command. After using this command, you have to wait a few seconds until the command is executed and open the shared folder again to pop up the user login dialog box.

Use the command "net use z:\\ WIN-I4BTR51SSDT\ Users\ paitouxi\ Desktop\ New folder 123 / user:guest" to add a network command, where "z" is the path mapped to the local, that is, after the mapping is successful, you can use "z:\" locally to access the shared folder, "\\ WIN-I4BTR51SSDT\ Users\ paitouxi\ Desktop\ New folder" is the remote shared folder, "123" is the password, and "guest" is the user name. You can see it in the "Network location" column in Windows Explorer.

5.5 explanation of Nic attributes

   right-click the network card in the control panel\ network and Internet\ network connections and select "Properties" to open the network card properties. As you can see from the image above, there are many options. When you select an item with the left mouse button, you can see its role in the description at the bottom of the page. Among them

Microsoft network client

   is used to access shared folders. If disabled, the remote shared host can be seen in the Network, but cannot be accessed. This sets whether you can access the shared folder of the host of the LAN to which the network card is connected. Each network card can be set separately. VMware Bridge Protocol

   the virtual machine used for VMware workstation is bridged to the physical network. But this protocol only appears when VMware workstation is installed. It will not be discussed here. File and Printer sharing in Microsoft Network

   is used to share folders. If disabled, the shared folder cannot be accessed by other hosts on the network. This can set which network card to which the shared folder can be accessed by the LAN host. Each network card can be set separately. Qos packet Scheduler

   opens the Local Group Policy Editor and finds the item "computer configuration → Management template → Network → QoS packet Scheduler", which is mainly related to the Qos packet scheduler. The Windows system reserves 20% of the bandwidth by default. The reserved bandwidth is for QoS, a new technology introduced in Windows 2000, and it does not necessarily mean that 20% of the bandwidth will be used. In fact, 20% of the bandwidth will only be used when applications are written using the QoS application programming interface to access the network. If these applications that use QoS API do not access the network, the reserved bandwidth can still be used by other applications. The modified value in the group policy refers to the maximum amount of bandwidth that can be used when a program written using QoS API needs to access the network. If we set it to 0%, it means that applications written in QoS API have to compete with other applications for limited bandwidth. The possible consequence is that the data that requires priority communication is not given priority. Of course, QOS, a new technology originally used to improve the quality of the network, has lost its meaning. You can see the link below that describes http://www.thewindowsclub.com/configure-reservable-bandwidth-settings-windows "configuring and limiting reservable bandwidth settings in Windows 10 / 8.1". You can also directly change the registry HKEY_LOCAL_MACHINE\ SOFTWARE\ Policies\ Microsoft\ Windows\ Psched to give it the numeric data 0. If Psched does not exist, create it. Link layer topology discovery response program

   is used to discover and locate other computers in the network and to build network topology diagrams. You can view the full mapping in the location shown in the following figure.

Link layer Topology Discovery Mapper Ihand O driver

   is used by other computers in the network to discover and locate their own location and to establish a network topology map.

That is, through these two programs, you can know the computers in the LAN, the switches that pass through, and the routers. 5.6 Network discovery depends on services and firewall ports and setting methods

   network discovery is to allow other hosts in the network to see the computer in the "computer" column of the "network".

   network discovery requires starting the DNS client, feature discovery resource publishing, SSDP discovery, and UPnP device host services to allow network discovery to communicate through Windows firewalls and other firewalls do not interfere with network discovery. If some cases, but not all of the above, are true, the network discovery status is displayed as Custom.

The services that    depends on are DNS Client,Function Discovery Resource Publication,SSDP Discovery, UPnP Device Host, which must be started to use network discovery.

There are two ways to open the Network Discovery firewall port:

1. Open Control Panel\ Network and Internet\ Network and sharing Center\ Advanced sharing Settings. Enable enable Network Discovery.

two。 Check the box to the left of Network Discovery in Control Panel\ system and Security\ Windows Firewall\ allow programs or functions to pass through Windows Firewall. This opens the corresponding Network Discovery port in the firewall.

In this way, you can find other hosts in the network that support the smb protocol. This host can also be seen by other hosts on the network.

   can open the Advanced Security Windows Firewall by clicking Advanced Settings in the left column of Control Panel\ system and Security\ Windows Firewall. Or directly win + r type wf.msc to open it. Click "inbound rules" or "outbound rules" in the left sidebar, and find "Network Discovery" in the middle display. You can see that there are many network discovery items, and you can view the ports used by network discovery.

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