人一個的雜記: CUHK Resnet FAQ

Subject

Beyond Scope of Service

We are sorry that we only deal with problems related to networking and data communications. However, your request is beyond the scope of our service, so we are unable to help.

Should you have other enquiries regarding the field of connection, please feel free to contact us again.

Check Proxy (Internet Explorer)

If you are using IE as your web browser, pleaes kindly check:

- Start your Internet Explorer
- Select "Tools -> Internet Options"
- Click the "Connection" tab, then click the "LAN Connection" button and see if there is any proxy server enabled. If yes, uncheck the option.
- Repeat the same step by select your VPN connection, then "Settings"
- Click the Ok button to save the change.

Please try it out.

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

Disable and Enable Local Area Connection

It is due to the fast startup feature in WindowsXP. It could take less than 30 seconds to start the WindowsXP in PC's with fast CPU. In such case, there would not have be sufficient time for getting an IP from the DHCP server.

To re-obtain a correct IP address(10.0.xxx.yyy),
1. Go to ""Control Panel"", double-click ""Network Connection""
2. Right click on the icon ""Local Area Connection"", select ""Disable"" and wait, then a red cross would then be displayed display next to the ""Local Area Connection"" icon
3. Right click on the icon ""Local Area Connection"" again, select ""Enable"""

Should you have further enquiries, please feel free to contact us again, thank you.

Enable Local Area Connection

From your information provided, it seems that your Local Area Connection has been disabled (or your LAN adapter is not properly installed). In order to connect to our VPN service, you have to first properly install LAN adapter and ensure that Local Area Connection is enabled.

To enable Local Area Connection:
1. Go to "Control Panel", click "Network and Internet Connections" and then click "Network Connections"
2. Right click on the icon "Local Area Connection", select "Enable""

Should you have further enquiries, please feel free to contact us again, thank you.

Error 1747

The error 1747 occurs when the "Client for Microsoft Networks" option is not installed.

1) Click "START", go to "CONTROL PANEL"
2) Choose "Network Connection"
3) Right click your vpn logo, choose "PROPERTY"
4) Go to "Networking", click "install"
5) Choose "Service", click "Add"
6) Choose "Client for Microsoft Network"
7) Click "Confirm"

Try to connect VPN again. If it fails, try to restart your PC and connect VPN again. Should you have further enquiries, please feel free to contact us.

Error 619

A. The Error 619 is usually caused by wrong setting in your VPN connection.

You may correct the Security section of your VPN connection to solve the problem.
(Please refer to the user guide in the ITSC homepage for VPN, at http://www.cuhk.edu.hk/itsc/network/vpn/vpn.html)

B. Firewall setting

It is due to the Firewall setting in your PC. Firewall is a system designed to prevent unauthorized access to or from a private network. Some have default settings that crash with VPN connection. At the moment, the ITSC does not recommend users to enable Firewall setting in their Virus Scanner and other internet security programs."

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

Error 691

Error 691 may due to the following problem:

A. multiple login

For the service of ResNet, ClassNet and Dialup (including connection via public ISP with VPN), multiple login is not allowed i.e. If you are using any of the above services, you would not be able to use any other services at the same time. Your problem is probably that someone was using your CWEM computing ID to make a connection. To solve this, just disconnect the other connection you made and connect to the VPN again.
You may also provide us the time of failure so that we can check your connection records and confirm this finding.

B. unterminated VPN session

It was because there was another idle connection initiated from your account left in the system. Please inform our administrator to remove it.
This is not the kind of problem that happens regularly. However, in case the same problem happens again, we suggest users to wait for some 30 minutes, then try again to connect to ResNet. You are also advised to disconnect to ResNet manually before shutting down your PC.

C. CWEM account disabled

You may check if you can login to CUHK webmail using your CWEM account at
http://webmail.cuhk.edu.hk
If you fail to login, you may have entered a wrong computing ID or password. Please check them again.

You can also view our knowledge base for more details
https://helpdesk.itsc.cuhk.edu.hk/kms/kblistentryAction?entryID=0000000088

Error 733 (L2TP)

You may follow the instructions below in order to fix your problem.

A. On the client disable the "Negotiate multi-link for single link connections" setting. To do this:
1. Start > Settings > Control Panel
2. Open "Network and dial-up Connections"
3. Right click the VPN network connection giving the problem and select "Properties"
4. On the "Networking" tab, click "Settings"
5. Clear the check-box "Negotiate multi-link for single link connections"

B. Check that the server is assigning or specifying TCP/IP addresses to user.
(Automatically obtain IP address from DHCP server.)

C. Check that the network protocol TCP/IP is installed in your system
(Note: Right-click Local Area Network button/The VPN connection icon and check this protocol entry in the list or not)

If your problem still exists, please feel free to contact us again, we are glad that we can help you, thank you.

Error 733 (through Broadband)

It seemed that your computer could not locate our VPN server via the network. To let us further check your network status AFTER you made connection to your ISP, please run the following command:

- Select "Run" from the Start menu,
- Enter the command "command" (for win98/me) or "cmd" (for Win2000/XP)
- Click the Ok button

Issue the following commands:

ipconfig /all
ping vpn.cuhk.edu.hk
route print
netstat -n

Please let us know all results you obtained. We'd try to figure out the problem you encountered.

By the way, did you run any personal firewall package such as ZoneAlarm or Norton Internet Security?

Error 734

Error 734 is due to incorrect setting in your VPN connection properties. To resolve this behavior, follow these steps:

1. Click Start, point to Connect To, and then click your dial-up connection.
2. Click Properties, and then click the Options tab.
3. Click to clear the "Include Windows logon domain" check box (if it is selected), and then click OK.
4. Click "Connect".
-If this procedure resolves the issue, and you can establish a dial-up connection; you do not need to follow the remaining steps in this article.
-If this does not resolve the issue, and you cannot establish a dial-up connection, go to step 5 to further troubleshoot this issue.

5. In the Connect dialog box, verify that your user name and password are correctly typed in the User name and Password boxes, and then click Dial.
- If this procedure resolves the issue, and you can establish a dial-up connection;
- If this does not resolve the issue, and you cannot establish a connection, please provide with us the following information:
a. Your whole error message / error code prompted or encountered;
b. Click START and RUN, then type "command" ("cmd" for Win2000 / WinXP users), type "ipconfig /all" and tell us the results;
c. Click START and RUN, then type "command" ("cmd" for Win2000 / WinXP users), type "arp -a" and tell us the results;
d. The version of your windows (e.g., Win98 / WinMe or WinXP?);
e. Your contact number for easy communication;
f. Your hostel address;
g. Your port number;
h. Are you using a notebook or a desktop computer?

We hope the above solution can help you to solve your problem. If you have further problem, please feel free to contact us.

Error 752

Error 752 may be caused by the IP assigned to you last time is still cached,
and Microsoft Windows try to get back that IP result in server conncetion fail.

Please try the following to see if it works

A. Release then renew IP

To re-obtain a correct IP address (10.0.xxx.yyy),
1. Click the "START" menu and then select "RUN...".
2. Type "command" and press "OK".
3. A command prompt window will appear.
4. Type "ipconfig /release_all" and press "ENTER". Retry a few times if it fails to get an "0.0.0.0" IP Address.
5. If it still fails, unplug your LAN cable from the ResNet port and try again. (This step is very important)
6. Plug your LAN cable back to the ResNet port.
7. Type "ipconfig /renew_all" and press "ENTER". Retry until you obtain a "10.0.0.0" IP address.

B. Re-installing the VPN adapter.

Another possible cause is that your VPN adapter setting is corrupted accidentally for some unknown reasons. You could solve this by re-installing the VPN adapter.
1. Click the "START" menu, select "SETTINGS" and then "CONTROL PANEL".
2. In the Control Panel window, select."ADD/REMOVE PROGRAMS".
3. Under Add/Remove Programs, go to the Windows Setup tab, select "COMMUNICATIONS", then click into "DETAILS".
4. In the "Communications window", check the box "VIRTUAL PRIVATE NETWORKING", then uncheck other boxes unless you understand their usage. Press "OK".
5. The system may ask you for the Windows setup disks to install the required files. After installation, the system will prompt you to restart your Windows. Click "YES" to confirm.

C. Wrong security setting

Error 752 may also caused by wrong setting in your VPN connection.
Please carefully check our page to make sure the security setting in your computer is correct:
http://www.cuhk.edu.hk/itsc/network/vpn/vpn.html

You can also view our knowledge base for more details
https://helpdesk.itsc.cuhk.edu.hk/kms/kblistentryAction?entryID=0000000087

If you have further enquiries, please feel free to contact us again, thanks.

Error 768 (L2TP)

Error 768 is caused by the termination of system service. Please try the following:
1. Right click "My Computer" and click "Manager"
2. Under the catagory "Service and application", choose "service"
3. Look for "IPSEC service". Check that this service is running.
4. If not, please start the service by double-click the entry and click the "Start" button in the prompted window.

We hope this can solve your problem. If you have any further problem, please feel free to contact us.

Error 769 (L2TP)

Error 769 may be due to wrong Hostname. Please refer to the following website for VPN client setup:
http://www.cuhk.edu.hk/itsc/network/vpn/winxp_setting.html
Please make sure that you have type in "ipsec-vpn.resnet.cuhk.edu.hk".

Also, please try to renew your IP address after you setup your VPN client:

To get a correct IP address
============================
A. Release then renew IP

To re-obtain a correct IP address(10.0.xxx.yyy),
1. Click the START menu and then select "RUN...".
2. Type "cmd" and press "OK".
3. A command prompt window will appear.
4. Type "ipconfig /release" and press "ENTER". Retry a few times if it fails to get an "0.0.0.0" IP Address.
5. If it still fails, unplug your LAN cable from the ResNet port and try again. (This step is very important!)
6. Plug your LAN cable back to the ResNet port.
7. Type "ipconfig /renew" and press "ENTER". Retry until you obtain a "10.0.0.0" IP address.

B. Disable then enable Local Area Connection

It is due to the fast startup feature in WindowsXP. It could take less than 30 seconds to start WindowsXP in PC's with fast CPU, such as Pentium4. In such case, there would not have sufficient time for getting an IP from the DHCP server.

To re-obtain a correct IP address(10.0.xxx.yyy),
1. Go to "Control Panel", double-click "Network Connections"
2. Right click on the icon "Local Area Connection", select "Disable" and wait, then a red cross would display next to the "Local Area Connection" icon
3. Right click on the icon "Local Area Connection" again, select "Enable"

Then run "ipconfig /all" and see if a 10.0.xxx.yyy address is obtained or not.

If you have further problem, please feel free to contact us. Also, if your problem presist, please reply us with your error messages and situations, IP address you obtained in "ipconfig" and socket label.

Error 769 (PPTP)

Error 769 may due to the lan card driver problem,
It may be corrupted accidentally for some unknown reasons.
You could solve this by re-installing the lan card driver.

Before the installation, Please make SURE you already have an updated lan card driver in your hand.

1. Click START, then SETTINGS and go to CONTROL PANEL;
2. Click SYSTEMS;
3. Click the HARDWARE tab; (For Win2000 / WinXP users, please click the DEVICE MANAGER button also);
4. Under the NETWORK ADAPTER, you should find your LAN card's model;
5. Right-click on the name of your LAN card, choose UNINSTALL;
6. Click OK and reboot your computer;
7. The system will then automatically search for your LAN card;
8. Follow the NEW HARDWARE INSTALLATION WIZARD as instructed to install your LAN card;

If you have further enquiries, please feel free to contact us again, thank you.

Error 769 w/o Further Information

Error 781 (L2TP)

From the error you reported, the error is probably due to the incorrect setting of the IPSec.
You have to enable the IPSec preshared key as discussed on the guide-line at http://www.cuhk.edu.hk/itsc/chinese/network/vpn/cwinxp.html
1. Go to "Start"-> "Control Panel" -> "Network Connections".
2. Right click the VPN Dialup icon, select "Properties".
3. At the "Security" Tab, You should see a "IPSec Settings..." button.
4. Click on "IPSec Settings..." and check the box "Use pre-shared key for authentication"
5. Enter the key "ipsec-vpn" and press "OK"
6. Try to connect again.

If you still have any problem on connecting to resnet, please feel free to submit problem at http://helpdesk.itsc.cuhk.edu.hk.

Error 800

Error 800 in window XP/2000 may due to many reason (e.g. wrong server name, firewall)

Please try out the following solution:

A. Release then renew IP

To re-obtain a correct IP address(10.0.xxx.yyy),
1. Click the START menu and then select "RUN...".
2. Type "cmd" and press "OK".
3. A command prompt window will appear.
4. Type "ipconfig /release" and press "ENTER". Retry a few times if it fails to get an "0.0.0.0" IP Address.
5. If it still fails, unplug your LAN cable from the ResNet port and try again. (This step is very important!)
6. Plug your LAN cable back to the ResNet port.
7. Type "ipconfig /renew" and press "ENTER". Retry until you obtain a "10.0.xxx.yyy" IP address.

B. Disable then enable Local Area Connection

It is due to the fast startup feature in WindowsXP. It could take less than 30 seconds to start WindowsXP in PC's with fast CPU, such as Pentium4. In such case, there would not have sufficient time for getting an IP from the DHCP server.

To re-obtain a correct IP address(10.0.xxx.yyy),
1. Go to "Control Panel", double-click "Network Connections"
2. Right click on the icon "Local Area Connection", select "Disable" and wait, then a red cross would display next to the "Local Area Connection" icon
3. Right click on the icon "Local Area Connection" again, select "Enable"
Then run "ipconfig /all" and see if a 10.0.xxx.yyy address is obtained or not.

C. Incorrect hostname

You may have entered an incorrect hostname for your VPN connection.
If you are connecting to the VPN in hostels, you should use ResNet. Please type "vpn.resnet.cuhk.edu.hk" for the hostname when setting a new VPN connection.
If you are connecting to the VPN in classrooms or some area in CUHK, you should use ClassNet. Please type "vpn.classnet.cuhk.edu.hk" for the hostname when setting a new VPN connection.
If you are connecting to the VPN at home or outside CUHK campus, you should use CUHKnet. Please type "vpn.cuhk.edu.hk" for the hostname when setting a new VPN connection.

D. Firewall

It is due to the Firewall setting in your PC. Firewall is a system designed to prevent unauthorized access to or from a private network. Some have default settings that crash with VPN connection. At the moment, the ITSC does not recommend users to enable Firewall setting in their Virus Scanner and other internet security programs.

E. Line speed

Similar to case B, it is due to the communication failure between your PC and the VPN server.

1. Click the START menu and then select "CONTROL PANEL".
2. Click "NETWORK AND DIAL-UP CONNECTIONS" (or "NETWORK CONNECTIONS")
3. Right-click on the "LOCAL AREA CONNECTION" icon and choose "PROPERTIES"
4. Under the name of your LAN card, click the "CONFIGURE" button
5. Choose the "ADVANCED" tab
6. On the left column, you should choose "Media Type" or "Connection Type" or "Line Speed", and then change the value to "10 BaseT" or "10 Mpbs Half-dulplex"
7. Click "OK" to confirm changes

F. Install WindowsXP Service Pack 1 and re-install LAN card driver

The networking component of your Windows or your LAN card driver may have been corrupted. You can install WindowsXP service pack 1 from the Microsoft website, and the latest LAN card driver from your manufacturer's website.

You can also view our knowledge base for more details
https://helpdesk.itsc.cuhk.edu.hk/kms/kblistentryAction?entryID=0000000085

Error 809

Please make a notice on the Norton Internet Security installed on Windows Vista, which can cause error 809. Even if you have never install Norton Internet Security, there should be a Norton Internet Security Free Trial provided by Windows Vista. It is known to interfere with CUHK's VPN connection. Even if you have no Norton firewall, but have the installation of Free version of Norton Internet Security, the error will still prompt out. You are advised to uninstall Norton Internet Security and have a _minimal installation_ of Trend Micro Internet Security (that is, install ONLY the anti-virus software component but NOT the firewall component), then turn on the Windows firewall.

The following is the solution of uninstall Norton internet security:
In order to uninstall the Norton program, I suggest you to download and run the Norton Removal Tool to remove the previous version of the Norton program from your computer.

NOTE: Norton removal utility is removal tool which removes all versions of Symantec products completely from your system.

For detailed instructions on uninstalling the Norton program using the Norton removal tool, please visit the following link and follow the steps provided in it.

Title: 'Download and run the Norton Removal Tool'
Document ID: 2005033108162039
Web URL:
http://service1.symantec.com/Support/tsgeninfo.nsf/docid/2005033108162039

In order to troubleshoot the VPN, please note that Norton AntiVirus includes a firewall that is called Internet Worm Protection (IWP). This feature protects the computer against unwanted attempts to connect to your computer.

In order to fix this issue, I suggest you to follow the document provided below:

Title: 'Cannot access your Virtual Private Network (VPN) after installing Norton Internet Security 2007'
Document ID: 2007032701294536
Web URL:
http://service1.symantec.com/Support/nip.nsf/docid/2007032701294536

Should you still have further problem concerning network usage within CUHK, please feel free to contact us at the electronic helpdesk or at our hot-line: 2609-8845.

Error Disabled (Email Template)

Submitted By YOUR_NAME
AR : AR_NUMBER
Hostel: HOSTEL_BUILDING, ROOM_NUMBER
Switch: SWITCH_NAME

Port Name Status Vlan Level Duplex Speed Type
----- ------------------ ---------- ---------- ------ ------ ----- ------------
2/21 RM:0112 0112A connected 260,901 normal a-full a-100 10/100BaseTX

Error Disabled Port

Your port had been disabled because our network equipment has received a lot of error packets generated from your computer. Now, your port is on the way of activation. You may try to connect to VPN after three working days. If you still fail to connect to VPN after a week, please feel free to contact us again.

Meanwhile, please check out the following suggestions carefully OR
you will face the same problem immediately after we re-enabled your port.

A. Network Bridge Enabled.

It happens mainly in Window XP. When the network bridge is used, your computer acts as a network bridging equipment, which sends out network protocol to communicate with the adjacent network equipment. However, these network protocols are not allowed to communicate with ResNet for security concerns. To disable the network bridge, please
1. Open "Network Connections"
2. Under Network Bridge, right-click "Network Bridge", and click "Disable"

B. Virus Infection

The delivery of a huge number of irregular message packets indicates that your computer may have been infected by computer virus. To avoid harming other users in the network, you should install the latest version of anti-virus software and scan your computer thoroughly. Please use the anti-virus software provided by CUHK and update the virus definitions daily. For details, please refer to http://avserver.itsc.cuhk.edu.hk/. Besides, please do not open or execute any files or e-mail from unknown source. If the problem still exists, we may consider to temporarily disable your computer from the connection.

C. Inappropriate Network Driver.

Please check if your network card driver matches your Windows version. We suggest you to update the driver at the manufacturer's website.

D. Faulty Cable.

Please check if your cable has been broken and replace it with a good one.

The reason for disabling your port is that our network equipment has received a lot of error packets generated from your computer. It takes extra processing time for the equipment to process these errors. In order to safeguard the security and the proper running of the network, the equipment therefore disables your network port automatically.

You can also view our knowledge base for more details
https://helpdesk.itsc.cuhk.edu.hk/kms/kblistentryAction?entryID=0000000002

Hard Coded IP Address

Please check if your have hard-coded an IP address onto your computer.
To ensure that you have not hard-coded your IP address,

( Windows 98 or Windows ME )
1. Click "START", then "SETTINGS" and go to "CONTROL PANEL";
2. Click "NETWORK";
3. Choose the "TCP/IP" settings of your LAN card ("TCP/IP -> [the model of your LAN card]), and click "PROPERTIES";
4. Under the tab "IP Address", choose "Obtain an IP address automatically" and "Obtain DNS server address automatically"
5. Click "OK" to reboot your computer;

( Windows 2000 or Windowns XP )
1. Click "START", then "SETTINGS" and go to "CONTROL PANEL";
2. Click "NETWORK AND DIAL-UP CONNECTIONS" (or "NETWORK CONNECTIONS");
3. Right-click on the "LOCAL AREA CONNECTION" icon and choose "PROPERTIES";
4. Choose "INTERNET PROTOCOL (TCP/IP)" and click "PROPERTIES";
5. Under the tab "General", Choose "Obtain an IP address automatically" and "Obtain DNS server address automatically"
6. Click "OK" to confirm changes;

(Windows Vista)
1. Click "Start" Menu, and go to "Network";
2. In "Network and Sharing Center", Click "Manage network connections"
3. Right-click on the "Wireless Network Connection" icon and choose "Properties";
4. Under the tab "Networking" , Choose "Internet Protocol (TCP/IP)" and click "Properties";
5. Under the tab "General", Choose "Obtain an IP address automatically" and "Obtain DNS server address automatically"
6. Click "OK" to confirm changes;

You can also view our knowledge base for more details
https://helpdesk.itsc.cuhk.edu.hk/kms/kblistentryAction?entryID=0000000483

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

Incompatibility between IPSec Client and ICS (Win98)

As the IPSec VPN client is not compatible with the Internet Connection Sharing (ICS) feature that is available with Windows 98 Second Edition (SE) and Windows Me. You must remove ICS before installing Microsoft L2TP/IPSec VPN client.

To remove Internet Connection Sharing (ICS), please follow these steps:
1. Click Start, point to Settings, and then click Control Panel.
2. Double-click Add/Remove Programs, and then click the Windows Setup tab.
3. Click Internet Tools, and then click Details.
4. Click to clear the ICS check box, and then click OK.
5. Restart the computer.

Please then try reinstall the Win98 VPN Client and follow the instruction on the ITSC webpage to finish the installation of the VPN setup.
Thanks for your attention.

Insufficient Information

We are glad to help you to solve your problem. From your information provided, we are still unable to spot out the cause of problem.
Please kindly help to provide the following additional information:

1. Your whole error message / error code prompted or encountered;
2. Click START and RUN, then type "command" ("cmd" for Win2000 / WinXP users),
(For Windows Vista users, hold down shift and right-click on desktop and you will get the option to "Open Command Window Here.")
type "ipconfig /all" and tell us the results;
3. Click START and RUN, then type "command" ("cmd" for Win2000 / WinXP users),
(For Windows Vista users, hold down shift and right-click on desktop and you will get the option to "Open Command Window Here.")
type "arp -a" and tell us the results;
4. Click START and RUN, then type "command" ("cmd" for Win2000 / WinXP users),
(For Windows Vista users, hold down shift and right-click on desktop and you will get the option to "Open Command Window Here.")
type "ping ipsec-vpn.resnet.cuhk.edu.hk" and tell us the results;
5. The EXACT time when the problem occurs;
6. The version of your windows (e.g., Win98 / WinMe or WinXP / Vista?) and the version of your windows service pack (e.g. WinXP SP2 / Win2000 SP4);
7. Your contact number for easy communication;
8. Your hostel address;
9. Your port number;
10. Are you using a notebook or a desktop computer?

The more information we have, more fast we can spot out the problem.
We are looking foward for your reply.

Mac with Unknown Version of OS

Mac OS can also access to CUHK VPN network. If you are using Mac OS 10.4 or above, you can just connect to resnet VPN with the VPN client provided by your computer.

If you are using a Mac OS of older version, please contact us with more details, e.g. your error messages, your configuration of the computer, etc. We can help you to solve your problem as soon as possible.

Reinstall LAN Card Driver

For your problem, we suggest you to re-install your lan card driver which may be the source of your problem.
Before you do so, please ensure that you have the correct version of your LAN card driver for installation purpose.

1. Click START, then SETTINGS and go to CONTROL PANEL;
2. Click SYSTEMS;
3. Click the HARDWARE tab; (For Win2000 / WinXP users, please click the DEVICE MANAGER button also);
4. Under the NETWORK ADAPTER, you should find your LAN card's model;
5. Right-click on the name of your LAN card, choose UNINSTALL;
6. Click OK and reboot your computer;
7. The system will then automatically search for your LAN card;
8. Follow the NEW HARDWARE INSTALLATION WIZARD as instructed to install your LAN card;

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

Reinstall VPN Client (WinME, Win98)

For your problem, we suggest you to re-install your VPN adapter which may be the source of your problem.
Before you do so, please ensure that you have the windows CD for installation purpose or you are using an internal windows version.

1. Click START, then SETTINGS and go to CONTROL PANEL;
2. Click ADD / REMOVE PROGRAMS;
3. Click the WINDWS SETUP tab;
4. Uncheck the COMMUNICATIONS option;
5. Reboot your computer as instructed;
6. Click START, then SETTINGS, go to CONTROL PANEL, go to ADD / REMOVE PROGRAMS, go to WINDOWS SETUP as before;
7. Select the COMMUNICATIONS option;
8. Click DETAILS button;
9. Check the DIAL-UP CONNECTIONS and the VIRTUAL PRIVATE NETWORKING options;
10. Click OK to reboot your computer again;
11. Try to connect again;

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

Release and Renew IP Address (WinME, Win98)

You may try to release and renew your IP address to see whether the problem could be fixed. The procedure of release and renew IP address is provided below:

To re-obtain a correct IP address (10.0.xxx.yyy),
1. Click the ""START"" menu and then select ""RUN..."".
2. Type the ""command"" command and press ""OK"".
3. A command prompt window will appear.
4. Type ""ipconfig /release_all"" and press ""ENTER"". Retry a few times if it fails to get a ""10.0.0.0"" IP Address.
5. If it still fails, unplug your LAN cable from the ResNet port and try again. (This step is very important)
6. Plug your LAN cable back to the ResNet port.
7. Type ""ipconfig /renew_all"" and press ""ENTER"". Retry until you obtain a ""10.0.0.0"" IP Address

Release and Renew IP Address (WinXP, Win2k)

You may try to release and renew your IP address to see whether the problem could be fixed. The procedure of release and renew IP address is provided below:

To re-obtain a correct IP address (10.0.xxx.yyy),
1. Click the ""START"" menu and then select ""RUN..."".
2. Type the ""cmd"" command and press ""OK"".
3. A command prompt window will appear.
4. Type ""ipconfig /release"" and press ""ENTER"". Retry a few times if it fails to get a ""10.0.0.0"" IP Address.
5. If it still fails, unplug your LAN cable from the ResNet port and try again. (This step is very important)
6. Plug your LAN cable back to the ResNet port.
7. Type ""ipconfig /renew"" and press ""ENTER"". Retry until you obtain a ""10.0.0.0"" IP Address

Then you may try to connect to VPN again, if your problem still exists, please feel free to contact us again, thank you.

Reset TCP/IP under WinXP

You cannot uninstall TCP/IP in Windows XP, because there is no Uninstall button for this protocol.
According to Microsoft, that is because TCP/IP is an integral part of the operating system,
and removing it would cause major problems.
You can, however, use the Windows XP command line utility NetShell to reset all IP-related Registry settings
to their default values. The result is a brand-new TCP/IP configuration.

The Netsh.exe program is located in the C:\Windows\System32 directory. To reset the TCP/IP configuration, enter the command:

Click START and RUN, then type "command" ("cmd" for Win2000 / WinXP users), type
netsh int ip reset vpn.log

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

Unstable Network Connection

The unstable network connection may caused by the following:
1. automatic timeout setting in Windows.
2. speed settings of your LAN card's configuration

A. Automatic timeout setting in Windows. You can try the following procedures to correct the situation:

(for Windows ME / 98 users)
1. Double click "Dial Up Networking" in "My Computer"
2. Right click on your VPN connection icon, left click on the "Properties" menu
3. Click "Configure" and select the "Connection" tab
4. Uncheck the item "Disconnect when idle for more than XX minutes"
5. Click the OK button to save the changes
6. On your desktop, right click "Internet Explorer", left click "Properties" menu
7. Click "Connection" tab and click "Settings"
8. Uncheck "Disconnect if idle for XX minutes"

(for Windows XP / 2000 users)
1. Open "Network and Dial-up Connections" in "Control Panel"
2. Right click your VPN connection icon, and choose "Properties"
3. Choose "Options" tab
4. Change "Disconnect when idle for xxxx" to "never"
5. Click "OK" and exit
6. Open "Internet Options" in "Control Panel" (WinXP users need to change to "classic view" before continuing)
7. Choose "Connections" tab
8. Select your VPN connection and click "Settings"
9. Click "Advanced" button
10. Uncheck "Idle xxxx minutes before disconnection"

B. It may be caused by the speed settings of your LAN card's configuration. Please set up the speed with "100 Mbps Full Duplex".

You can re-configure your LAN card's speed as follows:
1. Open "Network and dial-up connections" in "Control Panel"
2. Right click your LAN card's connection (usually stated as "Local Connection") and click
"Properties"
3. Make sure that you have selected the right connection of your LAN card, and click "configure"
button
4. In the "Advanced" tab, find "Connection Type / Media Type / etc", and change it to "100 Mbps Full Duplex"
5. Click "OK"

You can also view our knowledge base for more details
https://helpdesk.itsc.cuhk.edu.hk/kms/kblistentryAction?entryID=0000000056

If you still face the same problem after trying the suggestions, please feel free to contact us again, thank you.

With MAC Address 00-00-00-00-00-00

Our system cannot locate your LAN card and show a invalid hardware address. To solve this, please update or re-install your LAN card driver.

Also, please click "Start" => "Run" and type in "cmd" in the text box and press enter. Then the command prompt window appears. Then type in "ipconfig /all" and press enter. This information can help us to locate your problem

If the problem presist, please feel free to contact us and supply with the details of your error messages.

人一個的雜記

2008年9月6日星期六

CUHK Resnet FAQ

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2008年9月6日 星期六

CUHK Resnet FAQ

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2008年9月6日星期六