疑難排解

重要

如果主機電腦和用戶端電腦之間遇到交互或連線問題，應始終確保所有電腦上都使用相同的 Veyon 組態。為了避免一般問題，建議在安裝期間或透過命令列介面自動執行組態傳輸，而不是使用 Veyon 組態器手動匯入組態。每次在故障排除期間進行變更時，還必須將組態傳輸到所有受影響的電腦。

無法存取電腦

有多種原因可能阻止使用 Veyon Master 存取電腦。

網路問題

首先應檢查電腦的一般網路連線。使用公用程式 ping (通常包含在每個作業系統中) 來診斷連線問題。

Veyon 服務問題

如果可以 ping 電腦，則應驗證 Veyon 服務是否正常執行。開啟 Veyon 組態器並開啟組態頁服務。在一般部分中，服務的狀態應顯示為狀態 正在執行。否則，可以使用按鈕啟動服務來啟動服務。如果不成功，您應該嘗試重新安裝 Veyon。如果新安裝沒有作用，您可以檢查 Veyon 服務的記錄檔以及作業系統的記錄訊息，瞭解錯誤訊息和可能的原因。此外，您也可以在作業系統的服務管理中找到更多提示或設定。

服務和防火牆設定

如果服務正在執行，您必須確認它偵聽正確的網路埠上的傳入連線。您可以使用 telnet 在本機電腦上驗證:

telnet localhost 11100

Besides general program output the character string RFB 003.008 must be displayed. If the output does not contain these characters you should check the network port number settings and Miscellaneous network settings, especially the Veyon server port number. You should try to reset them to their default values.

Next the same access has to be possible from a different computer in the network. The utility telnet can be used again for the diagnosis. The program argument localhost has to be replaced with the name or IP address of the corresponding computer. If the access fails please ensure that the option Allow connections from localhost only in the Miscellaneous network settings is disabled. Additionally computer access control should be disabled initially as the service otherwise might listen on localhost only. This can happen if the external access would be denied because of currently matching rules. If both settings are correct the output of

netstat -a

必須指示服務不是 (只) 接聽在 localhost 或 127.0.0.1 (狀態為 LISTEN 或類似)。

If the port access from remote computers still fails usually a firewall prevents the access and has to be reconfigured accordingly. On Linux this concerns settings of iptables, ufw etc. Consult the corresponding manuals of the used software. On Windows Veyon automatically configures the integrated Windows firewall if the option Enable firewall exception in the Miscellaneous network settings is set to its default value (enabled). If a 3rd party firewall solution is used it must be configured to allow external access to TCP ports 11100 (Veyon server port) and 11400 (demo server).

身份驗證設定

錯誤的另一個原因可能是身份驗證設定錯誤或不足。對於首次測試，您應該在兩台電腦上選取登入身份驗證，而不是金鑰檔身份驗證。一旦本機電腦上的身份驗證測試成功，外部存取也將工作。

如果使用金鑰檔身份驗證，則主機電腦上的金鑰檔與用戶端電腦必須完全符合。在用戶端電腦上，公開金鑰檔的內容必須與主機電腦上的內容完全相同。如果存取仍然失敗，則對金鑰檔的存取權限可能是錯誤的。 Veyon 服務需要具有 公開金鑰檔 的讀取權限，而 Veyon Master 的使用者必須能夠讀取 私密金鑰檔。如果問題仍然存在，應在所有電腦上刪除金鑰檔的金鑰檔目錄並在主機電腦上產生新的金鑰組。然後必須在所有用戶端電腦上再次匯入公開金鑰。

電腦存取控制的設定

An incorrect configuration of computer access control can also lead to computers being inaccessible. Initially it’s recommended to disable computer access control completely using the Veyon Configurator. This allows determining which method for computer access control is possibly incorrectly configured.

If authorized user groups for computer access are used you should check whether the list of authorized user groups is complete and whether the accessing user is a member of one of these user groups.

Improperly configured access control rules can also cause problems with accessing computers. It is necessary to always specify at least one rule to allow access under certain conditions. If this is ensured, a temporary test rule can be inserted at the end of the list for further debugging. This rule should be configured so that the option Always process rule and ignore conditions is enabled and the action Allow access is selected. This rule can then be moved up in the rule list step by step until the test returns the desired positive results and the access works. The access rule located directly below the test rule is then the cause for the access denial and can be examined more closely and corrected accordingly. Don’t forget to remove the test rule afterwards to prevent unauthorized access.

防毒軟體

It has been reported by some users that an installed anti-virus software caused problems with Veyon, especially regarding the Veyon Service. As part of the troubleshooting process you should temporarily disable the anti-virus software in order to figure out whether the anti-virus software is the cause of error. If so, try to add an exception for the Veyon Service after enabling the anti-virus software again. Alternatively contact the vendor of your anti-virus software for further assistance.

Time synchronization problems

When using logon authentication, Veyon requires the operating system to reliably perform user authentications on all remote computers. Especially in AD/Kerberos-based environments, authentication may not work reliably when the system clock is not synchronized with the domain controller or authentication server and differs significantly. Therefore make sure time synchronization is configured and working properly if you encounter sporadic connectivity problems when using Veyon.

未正確儲存/載入設定

更新到新版本的 Veyon 後，在極少數情形下可能會發生某些組態金鑰不一致，需要重新建立的情形。這可能會造成設定未正確儲存或重新載入，例如內建位置和電腦資訊。在這種情形下應重設組態，並根據預設值重新組建。

LDAP 目錄中的位置和電腦不顯示在 Veyon Master 中

請確認:

網路物件目錄在組態頁面一般設定為 LDAP Basic 或 LDAP Pro
LDAP 整合測試列出位置的所有項目和列出所有位置都成功並返回正確的物件
在組態頁主要所有用於微調行為的選項都設定為其預設值

自動選取目前位置不起作用

If the option automatically selecting the current location is activated, but has no effect when starting Veyon Master, you should first make sure that the master computer is also listed as a computer for the respective room in the network object directory.

If the problem persists although all entries in the network object directory are correct, there is usually a problem with the DNS configuration in the network. Make sure that computer names can be resolved to IP addresses and reverse lookups of IP addresses return the corresponding computer names. On most operating systems, the DNS diagnostic tool nslookup is available for this purpose. Calling the program with the local computer name as an argument must return a valid IP address. A second call with the determined IP address must again return the computer name.

If the function does not work as desired despite correct DNS setup, in the second step the log level can be set to the highest value (Debug messages and everything else). After restarting Veyon Master, you can search the log file VeyonMaster.log in the log file directory for further error causes. The lines with the messages 「initializing locations」 and 「found locations」 indicate which host names and IP addresses were used to determine the location and which locations were eventually determined on the basis of these information.

螢幕鎖定可透過 Ctrl+Alt+Del 繞過

To completely block all keystrokes and keyboard shortcuts in screen lock mode, you must restart your computer after installing Veyon on Windows. Without a restart, the Veyon-specific driver for input devices is not yet active and keystrokes cannot be intercepted.

在示範模式下，用戶端電腦上只顯示黑幕或視窗

請確認:

in the configuration page Service under network port numbers the demo server port is set to its default value 11400
on the configuration page Service the firewall exception is enabled on the master computer or a third party firewall is configured to allow incoming connections to TCP port 11400
the user of Veyon Master has access to its own computer (i.e. the local Veyon Service). In the access control ruleset there may exist a rule prohibiting access to the computer if a teacher is logged on. In this case you should create a rule with the condition Accessing computer is localhost enabled as far up the list of rules as possible. Otherwise the demo server is unable to access the teacher computer’s screen content and distribute it to the client computers.

Veyon 伺服器在 Linux 上出現 XIO 或 XCB 錯誤停止回應

There are known issues with specific KDE and Qt versions on Linux causing the Veyon Server to crash. This affects several other VNC server implementations as well. If you’re affected by such crashes consider upgrading KDE/Qt. As a last resort you can disable the X Damage extension in the VNC server configuration. This will however decrease overall performance and increase the CPU load.

Some features such as starting apps or opening websites do not work

It has been reported that problems arise if the username and the computer name are identical. When logging in a user called student on a computer with the hostname student, some features will fail to start when the user session is being controlled via Veyon Master.