Monday, October 26, 2009

Why inner DIV doesn't inherit background color

What situation will make an inner DIV not inherit the background color of the outer DIV? It usually happens when CSS or HTML style's float attribute exists. Considering the following HTML,
<body style="background-color:#F8E0EC;">
<div style="background-color:#fff;padding:20px;border:10px solid blue;">        
  <div style="float:left;width:330px;border: 1px dotted red;">
        3:30 PM
        5 main street
The picture will look like this:
inner div floats outside
As you can see, most inner DIV text are sitting outside the blue box (outer DIV). If you take out the float attribute, everything will work fine. The reason of using float attribute is that you may want to have another DIV sit side-by-side together. In this situation, you need to put
   <div style="clear:both"></div> 
at the end of the inner DIV, just before closing the outer DIV. In my example, I will continue to use only one inner DIV. You can test it yourself with two.
<body style="background-color:#F8E0EC;">
<div style="background-color:#fff;padding:20px;border:10px solid blue;">        
  <div style="float:left;width:330px;border: 1px dotted red;">
        3:30 PM
        5 main street

  <div style="clear:both"></div>

inner div floats outside
Now the problem is fixed.

Saturday, October 24, 2009

Key Notes for Complie, Install, and Using OpenSSL on Windows

Ref Docs: Generate Private Key | Generate Certificate | config | openssl | openssl req | openssl ca

I downloaded three versions of OpenSSL and have successfully compiled both versions 0.9.8h and 0.9.8k. But the compilation failed on the latest beta version 1.0.0-beta3. In this document, I will describe how I compile, install and use OpenSSL into IIS on Windows. Note that the part using/configure OpenSSL is missing in this article. I haven't completed it in my writing. I was distracted by something else while I was working on this article. All my notes are still in my local computer. After a while, I completely forget about it. Since it is just for my own notes or references, I decide to leave it as-is. If I upgrade my OpenSSL, I may update this info as needed.

Tools needed:
  • Cygwin, or GNU tar and gzip: If you don't have cygwin, I would recommend to install it. You will find a lot of useful UNIX utilities such as tar and gzip. For openssl purpose, you need both tar and gzip to unpack the openssl-<version>.tar.gz file. Don't use WinZip, WinRAR or similar to uncompress the file. Or most likely you will have problems in compilation. You can use GNU tar and gzip instead if you have them. But I have some troubles using them.
  • MinGW: It is optional unless you compile openssl under cygwin with error(s). MinGW can compile source under a DOS command prompt. For a unknown reason, I cannot compile openssl under cygwin but I can compile it under DOS with MinGW. I also cannot compile it with VC++ either.


The followings are the steps I was taking to get the job done and MinGW is the compiler.
  1. Uncompress the file using tar and gzip. You can do it under either DOS or Cygwin Bash Shell enviornment.
    tar zxvf openssl-x.x.x.tar.gz

    With the z option, tar will automatically involve gzip to work together. Thus you must have gzip around and they both must sit in the same directory.
  2. After the file extraction, look for INSTALL.W32 file for the detailed Windows compilation instructions
  3. Ensure MinGW's bin directory is in the PATH environment. Or you can do the following at the command prompt, assuming your MinGW installation directory is at c:\mingw.
    set PATH=c:\mingw\bin;%PATH%"
  4. Change directory into OpenSSL-x.x.x directory, for example,
    cd c:\openssl-0.9.8k
  5. Type the following command to compile:
  6. The compilation will take a while. When it is done successfully, it will end with the following two lines:
    Generating the DLLs and input libraries
    Done compiling OpenSSL
  7. Two DLL's files ( libeay32.dll and libssl32.dll ) are found in the root directory (e.g., c:\openssl-0.9.8k). MinGW also produced two additional directories: out and outinc.

    openssl.exe and other executable files are found in out.

    outinc contains all the headers files.

After Compilation

There is no actual openssl installation. As openssl claims, if you compile it under cygwin, the compiled version will be placed under cygwin directory at /usr/local/ssl. In my case (because I use MinGW for compilation) , I have to repackage the files and the directories myself.
  • Create the following directory tree:
    openssl dir
  • Copy files (assuming the above step is created at c:\):
         copy out\*  c:\openssl\bin
         copy outinc\openssl\*  c:\openssl\include\openssl
         copy out32dll\libeay32.dll c:\openssl\lib
         copy out32dll\libssl32.dll c:\openssl\lib
         copy apps\openssl.cnf  c:\openssl\config

Master Configuration File Location

The master openssl.cnf is located inside the apps directory.

The openssl configuration file name is openssl.cnf, which is expected to be found at /usr/local/ssl/ (unix file path style). If you are using cygwin, this ( /usr/local/ssl/openssl.cnf) should be under your cygwin directory. Unfortunately, I cannot compile it under cygwin. Again, I am using mingw as my compiler. With it, the master configuration file is located inside the apps directory.

Possible Issue

When you answer Y to sign the certificate/request again, you may have the following error:
Sign the certificate? [y/n]:y
failed to update database
TXT_DB error number 2

Solution: You cannot have two certificates that look the same. To fix this, there are two options:
  1. You can remove the line in the database (index.txt) or replace the index.txt with an empty one. Or
  2. you can revoke the previous certificate, e.g, openssl ca -revoke myCA.cer

Friday, October 23, 2009


When you are running a script or compiling a program in a Cygwin Bash Shell, you may encounter the following error:
\r command not found

To handle it, you need to convert this DOS ending character \r at the end of each line to UNIX format.

In Cygwin or UNIX, you can convert an input file (INFILE) in DOS format to an output file (OUTFILE) in Unix format by calling:

> tr -d '\15' < INFILE > OUTFILE
Or you can run this command:
> d2u --safe *
Here --safe mean not touching any binary files. The * is wild card for all files in the current directory. You can type d2u --help in bash for help.

Similarly, you can use u2d to convert UNIX ending line character to DOS format.

Monday, October 19, 2009

Free long distance calls including International calls

Free International Long Distance Calls Talkster or FreeRinger

Note that Talkster is no longer free beginning of the year of 2010.

Talkster provides free International phone-to-phone calls including landlines and mobile phones. As of today, it supports 38 countries. I have been using it for a year already. You don't have to sign up before use. Simply go register your phone and your callee number in exchange for talkster numbers and then you both are ready to call each other.

Each call seems to be limited to 2 hours.

If you don't use the talkster number for a while, you may not be able to use it and call. In this case, you may get a busy signal saying the line is not available or something. Simply go to Talkster again and re-input the numbers; the problem should be cleared itself.

FreeRinger uses Talkster service to provide free calls. With FreeRinger, you don't have to use a physical phone to make calls. You can make calls via Computer-Phone and send/receive calls via your SIP phone. There is absolutely no software download and it is completely online. However, you have to create an account with them first. This feature is great for off-country traveling, or you don't want to use a physical phone to make calls.

Free Fax: Please see my another post

Free WiFi Locator: JiWire
It lists all available free WiFi hot pots in 140 countries. The service will be no use if you don't have an Internet to access it first. Thus, you would be better to do the research of the location while you are being connected.

Saturday, October 17, 2009

Free Fax

Oh, no, I cannot send fax. I did in the past when I still had my land line. Not any more now. Traditional fax can't work well with VoIP. Why? See this for why faxing over IP network doesn't work. I am currently using MagicJack which sends data/voice via VoIP protocols. What can I do?

I tried quite a few products but there is only one which actually works. The service can send fax internationally. I also tested this out and it worked like a charm. The other important thing is that it is free!

You can use their service either by your mobile phone or directly at their site : qipit
  • You need to create an account with them first.
  • All documents must be in picture format, not PDF or any other kinds of format. Apparently, the service only operates on pictures. It will convert a picture file into a PDF file for email or fax.
  • You can upload pictures to your account by MMS or email to either or
  • The detail instructions could be found here.
  • It supports a multiple-page document.
  • For free service, the fax limit is 5 per week counting from each Sunday at 12:01 am in Paris, France.

Tuesday, September 22, 2009

Changing account info with yahoo is difficult

I have seldom used yahoo email account since they no longer support POP. Recently, I have logged on to it and was forced to add new security questions due to their new design and interface. Then I found that there is an error in my birthday and would like to amend it. Unfortunately the field is not available. I sent them a question asking about how to update it.

The answer is that I have to wait for 35 days in order to edit the field since my security questions are newly added/updated. The other ridiculous thing is that this field will be public by default (see the email exception below). I can't hide it until 35 days. How difficult to make the personal account information becomes editable immediately since they have already had the interface? Why do I have to wait 35 days? Anyway, I simply hide my entire profile since I am not using it for connections.

The following is excerpted from the email answered by Yahoo:

"Once the 35 days has passed, you will be able to edit your age from the "Edit Profile" link in your Yahoo! Profile. Edit fields for your birth date will be available on that page after the 35 day period. You will also be provided a field that will allow you the ability to hide your age from other users."

September 28, 2009
The 35 days have already passed. I still don't see that there is a field for age or birthday available at the Edit Profile page. Everything is the same as before only showing Full Name, Display Name, Location, Verify and two buttons (Save and Cancel) - that's! The page with the birthday info I found is only available at Account Info page. Unfortunately it is not editable at that page. I have never seen Age field that Yahoo keeps mentioning. They should have posted the screenshot at their support page to guide people. Such a question has been asked several times if you do a search on Google, but no one is fond of their answer. I have been talking to Yahoo back and forth 4 times. I can see that it is wasting time. Wait for 35 days? Then what? The information is still unavailable. Yahoo support just wants to dismiss you ASAP regardless of your satisfaction with their answer. Luckily, I don't subscribe their pay service. It is totally not worth it! Although it is free, Users should have the right to make corrections on their personal data. It seems to me that Yahoo promotes false information and discourages users to make amendments!

Side note:
  • A few years ago, a friend of mine's email accounts were hacked. She successfully had her Hotmail back but not Yahoo. She was extremely furious with Yahoo and advised everyone to reconsider if he or she chooses Yahoo's service while there are better services in somewhere else.
  • If you lose your password, you probably will be out of luck to get your account back from yahoo. I lost once in the past but luckily I remember it a month later to have it back. Their service support is very poor regardless of how much information you provide them. Their answer is always the same, "Sorry, your data doesn't match with their file." So the case is closed.

Thursday, September 3, 2009

Your Facebook photo alumn is never private

Regardless of your permission setting on your Facebook photo albums, they are all considered public. Each album is assigned an unique access link. It can be found at the bottom of the album page (the link is only visible to you). Don't think you set the photos are only viewed by you; then the rest of the world can't see it. Facebook has explicitly said in every album that "Share this album with anyone by sending them this public link: ...." Obviously your photos are viewable to non-facebook users, which means everyone. The link will look like this:

In the above example, l=abcdefghij, I believe, is sort of the public access ID. Without it, non-Facebook users cannot go in the album or see the photo. Therefore, don't casually distribute your album link to anyone. Without it, the link is difficult for human educated guess; possibly a hack program can. If you have ever published the link to someone else, you may consider to create a new album by transferring the existing photos to the new one and then delete the old album. The new album will be assigned a new public access ID. Such a way it may keep your photos more safer. As of this writing, there is still no guarantee to keep your photo on Facebook 100% private.

Blogger fails to identify users

Some people are unable to provide comments with their own identities using their Google accounts, because blogger always mistakenly tags them with someone else. Clearing cookies and cache for the browser won't make a difference. I am one of them. Thus, I won't comment friends' blogs with my Google Account identity because it will never be me. Luckily most of them allow visitors to sign with Name/URL.

I just did a little bit experience using a public computer where I have never been before by posting a comment back to my own blog. When I posted a comment, I logged in with my Google account, hoping my name will show up correctly. No, never! Instead, I became someone else. The worst is that I don't even know who that person is. Obviously, it is not the issue of you possessing many Google accounts as blogger claims. Unfortunately, blogger has never admitted the fault and has no plan to fix it. In looking back the complaints posted to the blogger user communities/forums, this problem has existed for a few years already. To be safe, if you have already experienced this problem, it would better not use Google account when you post a comment to blogger, use OpenID if you have another identity with some other sites, or use Name/URL if the blog allows anonymous posting.

Blogger cannot correctly handle their own Google account for comment posting. Why not put Google account under OpenID category and handle it the same way as other OpenIDs? This problem discourages people using (or signing up) Google accounts and also degrades user experience.

Monday, August 31, 2009

How to make your Facebook note visible to everyone?

[Update on Oct 1, 2010]

Facebook has changed a lot since March 2010. This post previously is no longer valid. In the past, Facebook Notes privacy setting possessed its own rules and settings which were different from other applications. Nowadays everything has been migrated. Notes acts like other applications and its privacy permission setting also follows the norms.

There are 4 categories in permissions: Everyone, Friends of Friends, Friends Only and Customize. The privacy permission is a lot of simpler. For example,

Setting permission to Everyone on a note means that this note is visible to everyone on Facebook, no matter if your wall is closed or the wall is visible only to yourself. However, if your personal profile is closed or only visible to certain people, the Facebook community may not see your note via your profile page unless they have your note URL, e.g.[your_note_id].

Unlike the past, the default setting of Notes application has no additional control on permissions. It will be applied to a note when published only when you don't make any permission change individually.

There are two areas to control if your Facebook note is visible to everyone.

First, you have to open your application permission door to the Facebook public. This application permission acts like a gatekeeper to control who can get in the Notes door and see your notes. The default permission is Everyone. Each individual note can be associated or applied by different permissions as needed. The default is still Everyone. If you set your Notes application permission to something else other than Everyone, and then you set your individual note to Everyone, your note will not be visible to everyone on Facebook. For example, if you set the Notes application permission to Only Friends, and you set your note to Everyone, it means that only everyone of your friends will see that note. In other words, the permissions for both the application and the note itself must be set to Everyone in order to share that note with the Facebook public. The following table could provides you some illustration.

Notes Application Permission Individual Note Permission Who can see the note
Everyone Everyone Everyone on the Facebook this is the default.
Only Friends Everyone Everyone of your friends on Facebook
All combination permission sets are not shown in this table. There are only two examples as discussed.

For me, I set my Notes application permission to Everyone; then I use the individual note permission to control who can see my notes. Some notes will be shared with the entire Facebook community, some with my friends, some with certain people and some even only for myself. If you are sure that you won't share anything to the Facebook public, you can just simply to close the door by setting the application permission to something else other than Everyone. Then the unwanted guests won't be able to get into your Notes territory.

How and where to set the application permission settings

Here is one of the ways to do it.
  • Navigate to your Notes page, and then at the top of the page (blue bar), mouse over Settings. you will see something similar as below.
    locate application settings
  • Select Notes Settings if it exists; otherwise, select Application Settings.
  • If you select Application Settings, locate the application called Notes and then click on Edit Settings.
  • Notes application settings
  • Now you're at the application setting control box where you can change the permission. permissions dropdown box

Individual Note Permission

In each note, you should find something similar to the following at the bottom of the note when you compose it. Set or change the permission as needed.
individual notes permissions box

One more thing, Setting Everyone permission to both the application and the note will not make it to be visible to non-Facebook users. All users have to log in onto Facebook in order to see your note.

Thursday, August 27, 2009

Location of IsolatedStorageFile

An IsolatedStorageFile is always persisted to a dedicated location by .NET isolated storage API. Each file, when it is first created, will be granted access at least to the current logged-on user plus other requirements. In other words, an IsolatedStorageFile is created based on isolated requirements called IsolatedStorageScope, for example,

  • User + Assembly
  • User + Assembly + Domain
  • Roaming + User + Assembly
  • Roaming + User + Assembly + Domain
  • ...
  • Machine + Assembly +
  • Machine + Assembly + Domain
  • ...
Note that you cannot initialize a storage with IsolatedStorageScope.User and IsolatedStorageScope.Machine together because IsolatedStorageScope.Machine represents All Users which include the current user. But either one of them must be present in the IsolatedStorageScope with others. In addition, you cannot use IsolatedStorageScope.Application if the application is not configured or running as a ClickOnce application, which implies you can only use either IsolatedStorageFile.GetUserStoreForApplication() or IsolatedStorageFile.GetMachineStoreForApplication() for store initialization only when the application is NOT a ClickOnce application.

The exact location to represent the isolated storage "file system" varies from operating systems.

For user scope (IsolatedStorageScope.User) related, the isolated storage is located at

   XP: %USERPROFILE%\Local Settings\Application Data\IsolatedStorage\
Vista: %USERPROFILE%\App Data\Local\IsolatedStorage\ 
For machine or all users scope (IsolatedStorageScope.Machine) related, the isolated storage is located at
   XP: %ALLUSERSPROFILE%\Local Settings\Application Data\IsolatedStorage\
Vista: %ALLUSERSPROFILE%\App Data\Local\IsolatedStorage\ 
All storage entry points (folders) will be placed under the above location(s). Each of entry point or folder represents a store assigned or automatically created by .NET when an IsolatedStorageFile is first created. Then you can create folders or sub-folders relative to that store location. After that, you can even create another IsolatedStorageFiles under those sub-folders.

Monday, August 24, 2009

Disappointed Again

Yesterday I spoke with my brother about my friend's condition, who is currently fighting for the fatal disease, brain cancer. I am extremely worry about him, especially I can't pay him a visit due to geographical living locations. His radiation therapy is not doing well and he could lose his battle.

My brother immediate reaction makes me even sadder. He shows no compassion. Instead he said, I should prepare to deal with this thing to happen in my life when I get older. Who doesn't know this? No one needs him to remind of this. A person will leave the world eventually. Especially when we get older, such a sad story will echo to our ears and/or surround us more often. However, could he pretend to show some sympathy by simply saying "I am sorry to hear this"? He is disappointed me again!

I've seldom shared any feeling of mine with my family although we try to remain a good relation. Unfortunately, none of my family members understand me or even know what I will feel and think. Since a friend always encourages me to try/share my feeling with my family, it still fails and makes me even more upset. It was not the first time, the second time or the third. I can't remember how many times my families did to me. This episode is just a simpe example from my brother. I am not going to try again. They always hurt my feelings. I would rather keep all to myself or share with strangers who don't know me. Speaking to no one here, I will at least feel a lot better inside.

Health or Job?

I have felt extremely sad lately. But there is nothing I can do. A friend of mine passed out and rushed into the hospital in March. Then he had a brain surgery almost immediately next day and was diagnostics to brain cancer stage 4. The recent radiation seems not helping. According to a friend's messages, he also loses his confidence to survive. Right now, he cuts off people contact or visiting. Since we both are not living in the same country, I am unable to visit him. Instead I am thinking him a lot daily. I am afraid of losing him soon. He is one of my best friends I've ever had. His patient, listening, caring and consideration manner makes me/everyone feel comfortable to stay with him all times. He was "never" sick; he was very health conscious and always kept his health in a good shape. I can't imagine he ran into this fatal disease. Can he survive through this? No one is sure to tell. I cannot deny that the chance is less (although there are plenty of successful stories), especially when he loses his own confidence to fight this. I am not a Christian but I would like to pray for him to re-get his health over. Please, God bless and help him!

For those people who are currently losing jobs, please don't give up. You all definitely will receive a second chance (and more chances) to start your career and life again, and then stay happy. Remember, your life is much, much better than someone's, who is fighting for a fatal disease, losing health or life. No health means no life and no second chance. Please precious what you have now and make wise use of your free time to prepare yourself for your next career.

I also wish everyone healthy and no worry of sickness or disease.

Again, God, if you can hear me, please help and save my friend. Show me your mercy and the miracle. Thank you.

Wednesday, August 19, 2009

Cyberbully and MySpace

MySpace Mom:
The first felong charge case in Missouri. A 49 years old woman Lori Drew posing as a 16-year-old boy on MySpace befriended with a 13-year-old girl Megan Meier first, and then suddenly sent Meier hateful messages and even published her private messages online that led Meier who had a history of depression commite a suicide. Drew was found quilty of three misdemeanors by criminal laws, which have been recently overturned by arguing that violating a Website's terms of service (TOS) is not a federal crime. Although Drew's actions or motives disgust me, I don't agree that violating TOS constitued "unauthorized access" that induces violating federal anti-hacking laws. Harassment may be a better term. Missouri has changed its anti-harassment laws to cover cyberbully.

Craigslist's Casual Encounters:
A 40-year-old woman Elizabeth Thrasher posted a fake "Casual Encounter" ad on Craigslist for a 17-year-old girl with whom Thrasher argued over the Internet (MySpace again). Thrasher was currently out of jail on a $10,000 bond and prohibited from accessing to the Internet. She could face 4 years in state prision in addition to $5000 fine maximum if she was convicted.

Two cases are done by women. What was in those two women's minds? Are they sick or full of retaliation?

Moreover, two cases are somehow related to MySpace, one of popular social networks. Nowadays, the social network gathering has become "real" although we are not physically face-to-face. Conversations and/or arguments without geographical barriers happen every minute or any moment. These two cases are just a simple reflection of real-life scenarios. Whenever there are humans group together in a place, there may be a crime or evil thing to be conducted somehow.

Tuesday, August 18, 2009

Annoying JavaScript Error on IE7

There is nothing wrong with IE. It is the bad work done by the Web developers who did a very bad job. Even Google is not doing a good job either. See its and most sites where installed Google Ads.

Since using IE 7, I keep getting javascript pop-up errors all the time. It is very annoying. "Disable Script Debugging" on your IE Internet settings doesn't mean you can eliminate all JavaScript errors. Some errors still continue popping up without your consent. I wish I simply put IE to retire but IE is still one of the popular browsers. I still have to use it for testing.

I am not a IE lover. I personally like to use Mozilla or now called Sea Monkey instead. Unfortunately, most sites don't support Mozilla but IE. Somehow I believe that IE popularity is related to its default distribution by the OSs. It induces users using it regardless of things users dislike.

Would this JavaScript problem be fixed soon? Unlikely, I think. IE 8 has already in the market. Later maybe IE 9, 10, ... Most sites focus on the latest technologies and have never bothered to fix things for the old browsers. Too bad for you if you're still using it! So don't count on them fixing it. Instead, users have to find their ways to deal with it.

Friday, August 14, 2009

Share or Trade?

I am reading news about "Rhapsody connects to Facebook, Twitter." You go and listen to a song you like at Rhapsody, then you post a link into your Facebook profile for sharing. Your friends see it and click on it; the link will bring them to Rhapsody site for further exploration.

Actually you're helping them to do advertisement for free and helping them to get more exposure in public - similar to the effect of "the word of mouth." The more people visit their sites, the more chances for them do business. It is just a marketing tactic. It looks like more and more business going to this direction.

Nowadays, sharing has another meaning attached to it - free advertisement - yeah, you share their content and they will make profit from your "sharing" - fair deal, huh? Or it may be called a trade!

Wednesday, July 22, 2009

Data Binding Expressions and Their Symbols

All data Binding Expressions are evaluated at runtime. There are three ways I know to include data binding expressions in ASP.NET. I don't find that Microsoft has defined any specific terms to distinguish them. For clarify and easy discussion, I would define ones here so that I can discuss and compare them.

These three (3) ways data binding expressions are:

Page-Level Data Binding
<%#  ...  %>


 <%# Request.MapPath("mytext.txt") %>
 <%# GetUserName() %>
 <%# MyAddress %>
 <%# 1 + 2 * 3 %>

The expression will be evaluated when you call DataBind() of the Page class or any other controls that support it such as the GridView, DetailsView, and FormView.  This expression can be applied to a reference to another control's property, a value of an object property, a member variable or a return value of a function. It can be placed anywhere in the ASPX file whenever it fits. For example,

    <%# PageTitle %>

  <img src="<%# GetImageFile() %>" alt="" />

  <asp:TextBox ID="txtFirstName" 
               runat="server" Text="<%# GetFirstName() %>" />

  <asp:HyperLink ID="lnkExample" 
                 NavigateUrl="<%# Example.Link.Value %>" 
                 Text="Example" runat="server" />

Page-level data binding is very common and easy to use. It also comes with two methods Eval and Bind. Eval provides readonly capability on data while data with Bind is updatable.

 <%# Eval("LastName") %>
 <%# Bind("FirstName") %>

For the detail how to use them, you can read more on your own.

Control-Level Data Binding
<%$  ...  %>


 <%$ ConnectionStrings:Northwind %>
 <%$ AppSettings:MyVariable %>

The expression will be evaluated when the page is rendered. There is no need to call DataBind(), unlike the page-level.

In addition, control-level data binding cannot be placed anywhere in the page by itself. Instead, it must be wrapped inside a control tag. The result of the expression is used to set that control's property. For example,

  <asp:SqlDataSource ConnectionString="<%$ ConnectionStrings:Northwind %>"  ... /%>
where the <%$ and %> is used to extract the custom connection string from web.config.

Currently, there are only two build-in expressions available. One is to extract connection string from the web.config (see the above example) and the other is to extract application settings from web.config.

  <asp:Literal Text="<%$ AppSettings:MyVariable %>"  ... /%>

Although you can always make your own custom expressions through CodeDOM (Code Document Object Model), creating a custom expression to use is not an easy task.

Script-Level Data Binding
<%=  ...  %>


 <%= Request.MapPath("mytext.txt") %>
 <%= GetUserName() %>
 <%= MyAddress %>
 <%= 1 + 2 * 3 %>
 <%= myClass.Name %>
 <%= myClass.Execute %>

  <script language="javascript">
     location.href = <%= MyForwardPageUrl %>;

Similar to the control-level, the expression will be evaluated when the page is rendered. Then, ASP.NET automatically inserts the value of the expression. There is no need to make any call to any DataBind() method either including Page.DataBind(). Similar to page-level, it can be placed anywhere in the markup page.

Monday, July 20, 2009

WebpartManager.ConnectWebparts Error

When executing the WebpartManager.ConnectWebparts() statement, I got the following error:

The ConnectWebParts method cannot be called after connections have already been activated (in WebPartManager.PreRender).

This problem occurred because I connected WebParts in Page_PreRender event.
     this.WebPartManager1.ConnectWebParts(provider, providerConnectionPoint,
                                          consumer, consumerConnectionPoint);

Moving it back to Page_Load event, everything works fine.

dbreader and dbwriter

If you have execution permission error when you run your ASP.NET, assigning dbreader and dbwriter roles to the ASPNET user will not help, especially your application only uses stored procedures. dbreader and dbwriter serve no purpose for this. They are related to table access. In this case, you need the following statement (if you're using SQL 2005).




By default schema is owned by dbo (any member of the sysadmin fixed sever role), which is different from db_owner (fixed database role).

If you don't specify schema on the table when you create it, the schema will be created under dbo privileges. The schema of the default LocalSqlServer database ASPNETDB is usually under dbo. Most of time, you need to run GRANT EXECUTE ON SCHEMEA statement.

What this statement does is to grant ASPNET

  • to execute stored procedures in the dbo schema.

If you change your mind later after you have granted the EXECUTE permission, you can always use REVOKE to remove the previous granted (or denied) permission, e.g.,


You can also use DENY statement to prevent someone from having certain permissions.

Can't View CHM Files

Whenever a CHM file is not viewable, I usually can go Properties of that file, click Unblock and then view the file. But this method suddenly doesn't work for me today because there is no Unblock button available.

I found that all the CHM files under that particular directory are not viewable. They were all working fine in the past and I also remember that I unblocked all those files. I am not sure if it is related to my most recent security update last week. The interesting is that, as soon as I copied those CHM files outside that directory, they become all viewable again. It is weird. Those CHM files are not in the network but my local drive. Well, the good thing is that the problem is solved.

In normal situation, see KB902225 to resolve CHM un-viewable issue.

Sunday, July 12, 2009

Verify who is ASP.NET Logon User

Usually I use Request.LogonUserIdentity.Name to check ASP.NET Logon User. It works for all types of users.


are only for Windows Authenticated user. For Internet users (anonymous guest), empty string is expected.

Request.LogonUserIdentity.Name will show you if the user is anonymous.

Monday, June 22, 2009

BeVocal vs Voxeo - Which one is good for a beginner?

Recently I have been learning ccxml and vxml. To begin with, I chose to do ccxml. But I recognized that I had to understand how vxml works before I could do something on ccxml. So in the past 2 weeks, I've begun working on vxml.

I signed up two free accounts with BeVocal and Voxeo respectively. Here are my simple comparison as an IVR beginner.

Category BeVocal Voxeo
Customer Support
and Forum
Worst! I have never got a response from them. I guess they are not entertaining any free account members. If so, they should mention this in their site. In addition, I am still unable to access their news forum discussion groups either. Extremely efficient, fast response. I have no problem to access their forum discussion boards.
Text to Speech (TTS) Sound more natural. I've seldom needed to do some customization in code in order to get a better speech. BeVocal sounds better than Voxeo, especially in reading a long sentence or a paragraph. A short sentence or a few words interpreted by voxeo TTS are okay. Otherwise, there is a tweak work, like manually using <break> or using comma to break the sentence into a few words together so as to make the speech more natural. This could be a problem if the text is instantly interpreted to a speech on the fly as soon as TTS engine receives text from a Web application. Voxeo claims that the speech will be better with their pay voice version. In addition, some words from voxeo TTS are never right to my ears. For example, slash or the punctuation / is always pronounced as flash. The word project sometimes is read as pro-jack or pro-ject.
Voice Recognition Acceptable. Frustrated. You'd better code with DTMF (telephone keybad input). I am not sure if voxeo's voice recognition engine is coded with genetic algorithm so that it could learn in the long run.
HTTP Integration As of my writing now, I still don't know where/what the actual voice URL of BeVocal is. Thus, I cannot forward the application control (using <goto>) back to the particular dialog of the vxml on BeVocal server. I need to duplicate all the scripts on my Web Server in order to continue the application. BeVocal probably has published the HTTP connection information somewhere in their site. However, for this moment, I just want to test and see how my Web application works with voice dialogs.

When you're serving your vxml via HTTP to BeVocal voice server, your vxml file must set CONTENT-TYPE header to application/voicexml+xml. Otherwise, an error is expected.
I like voxeo approach using Web URL as their voice browser URL. It is a lot simpler for a beginner like me. The concept is very simple and easy to implement. With Web URL approach, I can simply use <goto> fetch my vxml files or return to any <form> of the same vxml file. There is no file duplicate needed on my Web server. And I don't need to research how to do HTTP Integration either at my early learning stage.

Voxeo will process your vxml with CONTENT-TYPE header set to either text/html or application/voicexml+xml.
Grammar and Syntax It is hard to say which one will be easy to work with. I cannot tell which one is more straight on the W3C spec either. They are slightly different.

For example, For BeVocal, we must have this; otherwise, it will be error out.
    <vxml version="2.1" xmln="">

For Voxeo, we can have:
    <vxml version="2.1">
    <vxml version="2.1" xmln="">

For BeVocal, it accepts the following and your script runs without any problem:
  <form id="q">
    <subdialog name="result" src="#personalInfo">  
For Voxeo, your scripts will never be run but it won't generate an error for you that makes debugging very difficult. I have left a note to their support team and hope that they will speak to their engineers about this.

To work around this, it is better to follow the W3C specification 100%. If something goes wrong, check the spec first.
How Easy to Test
an Application?
BeVocal displays 1-800 number + pin, a direct number and SIP on every Web page saying for application testing. For unknown reason, I can only use the direct number. The 1-800 number and SIP have never worked for me. Voxeo provides 5 ways to test every application: 1-800 + pin, a direct number, Skype, FWD, SIP and even iNum number. Every method works for me like a charm.
How Many Applications
Can be Tested
at a Time?
One. BeVocal only allows you activating an application for test at a time. Many. Each application will be assigned to different numbers and pin.
Application Debugging BeVocal's Log Browser can be used as a tool to debug your vxml but you cannot view that particular log while you're executing the application. Each log can be reviewed after execution with color highlighting. All errors will be highlighted in red, letting you know exactly which line it is, similar to other programming debugging tool.

Their Vocal Debugger will allow you walking through the script and even pause your application at certain point. The pause is not a break point unlike other programming tool where you can set it beforehand. You only set it when you run the application.

If you don't like to use a phone to test your voice application, you can use their Vocal Scripter. It simulates the dialing process for connection and convert your response in text to voice back to your application. But I am not fond of it. I would like to test the voice quality as well.
Voxeo only provides a single tool called Application Debugger. You can have it open while you are testing your application. When an error occurs, it will highlight it in red. Unfortunately, the error is not exactly what we are looking for in our script. They are mostly Java stack trace error with the line numbers that we don't care. It is good for Voxeo supports or their developers for further diagnostic. I like BeVocal giving me exactly which line of my script is having a problem.

Unlike BeVocal debugger, Voxeo debugger won't allow you walking through the application directly. But it provides the execution messages as if it documents the call scenario so that you can look at the output and see if there is any abnormality.

Their error logs can be retrieved in a later time but as soon as you close your debugger, all the color highlighting is gone forever. The log is in plain text. Within a day, you can easily view it with your browser. Otherwise, you have to download it first because Voxeo will put them in a .GZ file. Because of this, I guess, Voxeo provides another tool called Prophecy Log Search. Still there is no color highlighting. At this moment, I don't find it useful but instead dislike it. To me, the tool is too heavy. The search is slow. JavaScript error is everywhere. It doesn't support both IE 7 and Sea Monkey 1.1.14, which I use intensively for my Web development.

One important thing that I learned within these two weeks is about a shadow variable. In the beginning of my learning, I was confused by this term being used in IVR. A variable is a variable. What does it mean a shadow variable? If I am correct, it is similar to a read-only property of an object. When we use one of the pre-defined tag element such as <record>, we are sure able to access its attributes. But this <record> tag consists of other properties available after the code execution like duration, size, termchar and maxtime. They are all read-only. In IVR world, such read-only properties are called shadow variables.

In closing, as a beginner, I would like to work with voxeo because their support encourages me to do more in their products, which I could not find this with other companies. Although I am frustrated by their voice recognition all the time, I found a way to work around it. Of course, I wish that voxeo could improve it in the future soon.

Sunday, June 21, 2009

Common ASP.NET problems related to IIS

The page cannot be found - return 404 for ASP.NET pages
OK button is grayed out while adding an IIS file mapping
Missing ASP.NET tab on IIS Manager
Parser Error: Could not load type

The page cannot be found - return 404 for ASP.NET pages

Make sure IIS is accepting the correct ASP.NET version. ASP.NET tab on IIS
On Windows 2003, you also need to ensure ASP.NET version is set to Allow for that ASP.NET version in Web Service Extensions. If you don't see ASP.NET extension, follow "Missing ASP.NET tab on IIS Manager" to install and enable it. After that, if you're running into the following error, your ASP.NET page probably has to run some shell command that requires additional permission.
   The compiler failed with error code 128.
   c:\windows\system32\inetsrv> "C:\WINDOWS\Microsoft.NET\Framework\v3.5\csc.exe" ...
In this case, go to Administrative Tools and select Services:
  • In the Services pane, locate World Wide Web Publishing Service.
  • Right-click World Wide Web Publishing Service, and then click Properties.
  • Click the Log On tab.
  • Click to clear the Allow service to interact with desktop checkbox.
  • Click OK.
Be sure to start the IIS and kill the browser before running the application again.

OK button is grayed out while adding an IIS file mapping

It is a small bug on IIS 5.1 with Windows XP.

To work around this:

After selecting the executable via the Browse... button, click on the textbox itself and the path will then be fully expanded. It in turn enables the OK button. [ref]

Missing ASP.NET tab on IIS Manager

Please ensure you have installed .NET framework first. For ASP.NET 2.0 or later, at the command prompt, do the following to install and enable ASP.NET on IIS:

%WinDir%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis -i -enable

Parser Error: Could not load type

You may experience the following error on IIS after you've published your ASP.NET application. But everything works fine in the Visual Studio. For example,

Parser Error Message: Could not load type 'SysAdmin.RunBatch'.

  • Check the Application Settings of your Web site or virtual directory, and then make sure there is Application name for it.
    • On IIS, right click the Web site or virtual directory, and then select Properties.
    • At Home Directory of Directory tab, click Create button to create the Application Name if it doesn't exist.
    • Execute Permissions must be at least set to Scripts only.
    • Click Apply and then OK to exit.
  • Check and ensure that the associated bin directory is resided with your aspx pages and Web.config. It is similar to the directory structure when you developed your application.

Friday, June 19, 2009

Add a file extension mapping on IIS for ASP.NET handler

  • Right click the Web site or the virtual directory and then select Properties.
  • Select Configuration button on Home Directory tab (for Web site) or Directory (for virtual directory).
  • On Mappings tab, click Add.
  • For ASP.NET 2.0 or later,
    Executable C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll
    Extension the file extension you want to map, e.g., .simple

    Here is an example.
    Add File Extension to IIS
  • Click OK, then Apply or OK.
  • Exit the wizard

Thursday, June 11, 2009

VMWare: Defrag or convert your 2nd virtual hard disk

In order to defrag or convert the 2nd disk, you need to reference or create the corresponding disk descriptor file that points to your 2nd disk. A disk descriptor file is simply a plain text file with the same extension as your virtual disk (vmdk). Its file size is usually about 1 or 2 KB.

  • Go VMware Server Console (VMware Server v1) or VI (VMware Server v2).
  • Select the VM.
  • Stop/shutdown the VM if it is running.
  • Select Edit Virtual machine settings.
  • Swap your 2nd disk node with the first HD node. Make sure the end result of your 2nd disk is at (0:0) node position:
    • In the Hardware tab, select Hard Disk at (0:0) node if you are using VMware Server v1; or select Hard Disk 1 for VMware Server v2.
    • Change it to other node. For Server v1, click Advance for selection. For Server v2, the selection should be at the right pane and named with Virtual Device Node.
    • Select your 2nd hard disk and change it to (0:0) node position.
  • Click OK and exit Virtual Machine Settings.
  • A new disk descriptor file in plain text is produced and named under your 2nd HD name with a VMDK extension, e.g., W2008My2HD.vmdk.
  • For Server v1, you can directly defrag the VM via the console. Or like v2, you can use virtual disk manager for defragmentation. With VMDK text file, you can do whatever you want with Virtual Disk Manager.

Don't forget to change it back to the original setting when you're done; otherwise, your VM won't boot.

Please remember that there is no need to use virtual disk manager to defrag a virtual machine (VM) if it is created in one big flat file or a set of preallocated 2GB files. Such a VM is only needed to defrag at the Windows level.

I would recommend to use flat or preallocated 2GB type for your 2nd, 3rd, ...and etc hard disk so that you don't have go through this hassle.

Sunday, May 31, 2009

Programmatically change Web project settings from dynamic port to static

If you have a solution consisting of many Web applications that currently use dynamic ports for debugging and now you want to modify them to be static, it will be tedious and extremely time-consuming to go in each project and change it. I developed an application to resolve this. For the future sake, I create a custom project template so that I don't have to go in the project properties and change it whenever a new Web application is created. Indeed, with my own project template, I can customize other things like libraries, references and macros I always use in a project.

Currently the application supports VS.2008. It takes the solution file (.sln) as an input to locate the project locations, and then goes in each indiviual project file (e.g., .csproj and .vbproj) to alter the setting. It only targets Web application including WCF. but not Website because the Web project properties for a Website is stored in .sln file.

The idea behind this application is very simple.

Define the settings

First, I create a setting file called vs.xml.   Currently the port is default to 2332.   The text in light green background is similar to the text you may find in your Web project file.

<?xml version="1.0" encoding="utf-8" ?>
<VisualStudio target="Visual Studio 2008 ">
  <SolutionFile version="10.00" desc="Microsoft Visual Studio Solution File, Format Version">
      <Langauge enabled="true">
      <Lanaguage enabled="true">
  <ProjectFile desc="Microsoft Visual Studio Project File">

<!-- Begin Settings --> <ProjectExtensions> <VisualStudio> <FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}"> <!-- Define Web Project Settings --> <WebProjectProperties> <UseIIS>False</UseIIS> <AutoAssignPort>False</AutoAssignPort> <DevelopmentServerPort>2332</DevelopmentServerPort> <DevelopmentServerVPath>/</DevelopmentServerVPath> <IISUrl> </IISUrl> <NTLMAuthentication>False</NTLMAuthentication> <UseCustomServer>False</UseCustomServer> <CustomServerUrl> </CustomServerUrl> <SaveServerSettingsInUserFile>False</SaveServerSettingsInUserFile> </WebProjectProperties> <!-- End of Web Project Settings --> </FlavorProperties> </VisualStudio> </ProjectExtensions> <!-- End of Settings -->

</Web> </ProjectFile> </VisualStudio>

The above vs.xml can be altered to support VS.2005. But I am going to describe the details here.

Define data structure to contain the settings

Create a data structure to contain all the Web properties; they are:


I use a Dictionary to capture this.

    private Dictionary<String, String> props;
When the application reads vs.xml, it will automatically load all the settings into this props Dictionary.

Function to alter the settings

The function SaveTo as shown below will update the settings into the project file based on the settings in props.   Note that my current version is slightly different now.

    /// <summary>
    /// Saves the settings to a specific file.  
    /// The project file must have ProjectExtensions/VisualStudio/FlavorProperties/WebProjectProperties
    /// nodes in order to be qualified for process.
    /// If the required elements under WebProjectProeperties node are missing from the specific document, 
    /// it will insert them.  
    /// The original elments in the document under that node remain intact if they don't match.
    /// </summary>
    /// <param name="fileName">the exact full filename of the project file for save</param>
    public void SaveTo(String fileName) {
      String namespaceUri = null, prefix = null;
      bool hasNamespace = this.HasNamespace(fileName, out namespaceUri, out prefix);

      XmlDocument xmlDoc = new XmlDocument();
      XPathNavigator navigator = xmlDoc.CreateNavigator();
      XmlNamespaceManager namespaceManager = new XmlNamespaceManager(navigator.NameTable);
      if (hasNamespace) {
        namespaceManager.AddNamespace(prefix, namespaceUri);

      XPathNavigator result = null;

      if (navigator.HasChildren) 
        result = navigator.SelectSingleNode(GetTargetNodeXPathExpression(), namespaceManager);
        throw new XmlException("Invalid file format, or it is not a Web project file.");

      if (result == null)
        throw new XmlException("It is not a Web project file.");

// up to here, "result" should be at node "WebProjectProperties" Dictionary dup = this.CloneProperties(); if (result.MoveToFirstChild()) { do { result.SetValue(dup[result.Name]); dup.Remove(result.Name); } while (result.MoveToNext()); this.changed = false; // all properties updated. if (dup.Count > 0) { // Missing properties we need to save, do INSERT to file now...; result.MoveToParent(); // position back to "WebProjectProperties" node this.AppendChild(ref result, dup); } } else { // no child found at "WebProjectProperties" node this.AppendChild(ref result, dup); // add a child nod with all the needy settings } xmlDoc.Save(fileName); // Now is time to save to disk.

if (hasNamespace) { this.ReverseNamespaceEnv(); } }

The main purpose of this function does is to update the project settings:
  • First, it locates the <WebProjectProperties> node to begin the process.
          <FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}">            
  • When the node is found, the function will temper the settings accordingly. All settings are stored inside the <WebProjectProperties> node. However,
    • If there is empty inside the <WebProjectProperties> node, all settings will be appended into it.
    • According to props, any missing setting(s) will be added accordingly.
    • Any extra settings cannot be found in props will remain intact.

Describe basic project file structure in Solution (.sln)

If you use a text editor to open .sln file and view it, you will find that each project may contain the following structure.

 Project("language_GUID") = "project_name", "project_location_or_file", "project_GUID"
   ProjectSection(...) = ...
A regular Windows or Web project will not contain ProjectSection. But if a Web project is type of Website, ProjectSection is used for storing WebsiteProperties because it doesn't own a project file. A WCF client may use WebsiteProperties for its ProjectDependencies. In sum, most projects only contain two lines: The first Project line and the EndProrject line. For example,
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MyTest", "Test\MyTest.csproj", "{7C0275FE-A91D-42E9-9EF1-5CCBC9D54C3C}"

Put everything together

All project locations registered with the solution are relative to the solution. Thus the location Test\MyTest.csproj in the above example is a relative path to its solution. As soon as the project location is found, convert it to the absolute path and then feed it to the function SaveTo, SaveTo will update the settings automatically.

In order to accomplish this, I create a Collection to contain all the project data found in the solution file.

    private Collection<ProjectIdentifier> projectCollection;
Each project data is defined in the following class:
  public class ProjectIdentifier {
    private String langGuid = null;
    private String name = null;
    private String location = null;
    private String guid = null;

    public ProjectIdentifier(String langGuid, String name, String location, String guid) {
      this.langGuid = langGuid; = name;
      this.location = location;
      this.guid = guid;

When everything is ready, loop through the projectCollection to update the project files:

  foreach (ProjectIdentifier project in c) {
    if (System.IO.File.Exists(project.Location)) {
      try {            
        if (project.IsWebProject()) {
            this.Backup(project.Location, this.txtTag.Text.Trim());

      catch (Exception ex) {
        String err = String.Format("Error occurs: {0}{1}{2}",
                                   ex.Message, Environment.NewLine, ex.StackTrace);
    else { // file not found or is not a file.
  } // foreach

Request my application

Before execution, my application will first back up the project file by default while it traverses the project folder. You can override this setting if you don't like it. The backup files can be programmatically removed in a later time when you feel comfortable with the changes. I don't know how useful for you but it certainly helps me to resolve a lot of tedious tasks.   Please feel free to leave me a message via the comment box for requesting this application if you think that it will be helpful to your issue.   Don't forget to leave your email for response. All application requests will NOT be left on comment.

Update August 6, 2009
On or off there are people requesting it. Here are the links where I put for storage so I am no longer to manage and distribute them myself. Please feel free to download it yourself. The code has been changed since this post.
Download: [ Source ] [ Binary ]

Note that: if you request it, then you use it as your own risk. I am not responsible for any damages that may occur.

Update July 15, 2011
Sorry, this application is no longer to download. It is hard for me to ensure that the files are still alive.

Additional notes for exporting project template

Template Directory Setting

The default location on XP for VS.2008 for template storage is at
      %USERPROFILE%\My Documents\Visual Studio 2008\Templates

You can change this setting at the VS.2008 menu bar: Tools --> Options.
Projects and Solutions

Export Template and Location

Create a blank project, edit it, import and reference your vital libraries.  When you're done, go File menu to choose Export Template.... Follow the wizard to complete the rest.

A project template is always exported to the default output folder where you cannot change:
      %USERPROFILE%\My Documents\Visual Studio 2008\My Exported Templates

The location you set at Projects and Solutions is primarily for the IDE to locate and load your custom templates.

If you accept the default setting Automatically import the template into Visual Studio when you export the template, IDE will automatically save a copy under that template folder where Projects and Solutions specifies.

Additional Template Folders

Project Templates Location
For the first time project template creation, three (3) additional folders will be automatically created for your template organization:
  • Visual Basic
  • Visual C#
  • Visual Web Developer
And your template file will stay with them at the same directory level. In my example, it is

I won't bother to put the template into one of those folders. You can drag the zip file into them if you want to organize it. As long as the template is under the template folder, the IDE is smart enough to loop through its sub-folders and find your template.

Edit Template Project Description

If you want to display a descriptive name on the IDE, go to the designated project templates folder and then do the editing. In my case, it is locate at H:\dev\Visual Studio 2008\Templates\ProjectTemplates.
  • Extract MyTemplate.vstemplate from the zip file and then open it for edit.
  • Locate <Name> and give descriptive name, e.g., My ASP.NET Web Application in C#
    <VSTemplate Version="2.0.0" xmlns="" Type="Project">
        <Name>My ASP.NET Web Application in C#</Name>
        <Description>A C# Web Application with a specific port (.NET Framework 3.5)</Description>
  • Save it and then zip it back to the original zip file.
Now try to add a new project, you will see the new template shown under My Templates. Add New Template

Wednesday, May 27, 2009

Problem of copying big file within a VM from the host

Have you ever experienced the following error?

Cannot copy <file_name>: The specified network name is no longer available.

Regardless of which Microsoft Windows, this problem occurs whenever you use Bridged mode on VMware network. Everything works fine with Host-only or NAT.

On VMware Server 1, I can disable the automatic bridging and then reconfigure other virtual adapter (not vmnet1 or vmnet8) as Bridged network by binding it to a physical adapter. This problem will go away. But this technique doesn't work for VMware Server 2. Thus, the problem still remains unresolved. What I can do is to copy files within the host to the VM, instead of inside the VM and do copying.

I don't believe that this post is correct. VMnet1 is Host-only. Indeed, I am not sure how we can change the nature of vmnet1 and vmnet8 to Bridged. Since the author of that post was using Host-only on vmnet1, certainly copying big file problem would not be an issue.

The other thing I would like to mention is that any newly added virtual adapter is always Host-only if the VMware Server is running on Windows. I am not sure if it holds true for other platforms.

Monday, May 25, 2009

Bridged vs Host-only vs NAT

I have been using VMware since 2002. I mostly use it for my development testing. There was no free version from VMware at that time. Luckily I got exposed to both WorkStation and GSX at work. Now I can have my free virtual server installed at home. All my VMware servers are running on Microsoft platform. I have both VMware Server 1 and 2 running on different machines. I like VMware Server 1 more than Server 2 because of its simple interface (which is VMware Server Console), a bit light weight to me and no restart needed when a configuration is changed.

Most my friends are confused by the 3 different modes network setting: Bridged, Host-only and NAT. Like most people, they use the default setting, Bridged. In the following, I am going to briefly distinguish the difference among these 3 network modes. I would also point out some issues existing in each mode, from a user point of view. Those issues applies to the free versions both VMware Server 1 and 2 running on Microsoft Windows platforms. For detail of how these 3 modes work or are configured, please consult VMware documentation ( Server 1 [Install, Manual] | Server 2 User Guide ).

Each VMware network mode is associated with a named virtual adapter. You can add and remove any virtual adapter you want. On Windows, the newly added virtual adapter is only bound to Host-only network. It may not be the case if you are running the server on other platforms but I don't know. In addition, you can configure a custom adapter to assoicate with each physical network adapter to fit your need.

These three basic VMware network are listed as follows.

Mode Virtual Adapter
Bridged : vmnet0 this is the default.
Host-only : vmnet1
NAT : vmnet8

Note that the issues listed in the following table are only applied to Microsoft Windows. I am not sure if they hold true for other platforms.

Bridged (vmnet0)

Communication and Visibility: The virtual machine (VM) acts as if a regular PC ran on the same physical network. You can go Internet and do whatever you want unless your software is hardware dependent. All VMs on vmnet0 are visible to others on the same physical network and vice versa.

Performance: In my experience, the VMware Bridged network is kind of slow. On Microsoft Windows, it is much slower on a workgroup network, compared to a domain.

DHCP or Additional Service: No DHCP service is provided. If you don't have a router or DHCP server running on your network, this mode may not suit for you. In this case, you should consider either Host-only or NAT network depending on if you want Internet access.


  • Big File Copy: Regardless of VMware Server 1 or 2, the file copying from the host inside a VM will fail when the file size is large enough. While the file is being copied from the network, the following error may occur: "Cannot copy <file_name>: The specified network name is no longer available." (Also see this)
  • Leaking IPs to physical network: The VM's IP is assigned by the physical network (e.g. your router or DHCP server). Thus, this problem doesn't apply here.

Host-only (vmnet1)

Communication and Visibility:The network communication of this mode is limited between the host and the VMs on the same vmnet1 adapter. Those VMs cannot make a connection beyond the host; thus there is no internet access capability. They remain hidden behind the host. You cannot configure it to expose any VM on vmnet1 to the physical network either.

Performance: The performance of Host-only (or vmnet1) is very fast. I usually use this setting for software testing especially when I don't need an Internet access. For example, I could run a database server inside a VM for a simple test.

DHCP or Additional Service: This mode provides DHCP sevice. If you don't have a router or a DHCP sever running on your network, this one comes in handy. This service can be disabled.


  • Big File Copy: Unlike Bridged, I don't experience any file copy problem regardless of size (also see this).
  • Leaking IPs to physical network: VWware DHCP may assign IPs to the PCs on the physical network and cause problems. I encounter this problem when I have my VM Server running first and then my other physical PC joins the physical network later.

NAT (vmnet8)

Communication and Visibility: All VMs using the adapter vmnet8 form a private network with the host. They all have internet access capability, but they are not visible to others beyond the host as if they are sitting behind their own firewall with the host. You can expose the VM for a particular access by port forwarding via NAT configuration provided by the VMware network utility (in the desktop Start menu: VMware -> VMware Server -> Manage Virtual Networks).

Because of its internet capability, I use it often for Web application testing and development too.

Performance: To me, it is faster than Bridged and could be as fast as Host-only.

DHCP or Additional Service: This mode provides DHCP sevice. If you don't have a router or a DHCP sever running on your network, this one comes in handy. This mode also provides NAT service for further network configuration. Both services can be disabled.


  • Big File Copy: Unlike Bridged, I don't experience any file copy problem regardless of size (also see this).
  • Leaking IPs to physical network: VWware DHCP may assign IPs to the PCs on the physical network and cause problems. I encounter this problem when I have my VM Server running first and then my other physical PC joins the physical network later.

Disabling VMware DHCP and NAT on Windows

If you are only using Bridged network, I would recommend to have both VMware DHCP and NAT services disabled. They are not used by Bridged.
On Windows, you can disable it via your Services console (services.msc) from Administrative Tools. These two services on Windows are called VMnetDHCP (for VMware DHCP Service) and VMWare NAT Nervice respectively.
  • Locate the service you want to disable.
  • Right click to select Properties.
  • From the Startup type dropdown box, select Disabled.
  • Click OK button.

Or run the following commands at the command prompt.
   sc config "VMnetDHCP" start= disabled 
   sc config "VMware NAT Service" start= disabled
Note that
  • start= must be in one single word.
  • There must be a space between the equal sign (=) and the word disabled.

Sunday, May 24, 2009

Apache ignores DocumentRoot in VirtualHost

Lasts night I got stuck in configuring a virtual host on Apache 2.2. Regardless of which port I set (including the port 80), the Apache server ignored my DocumentRoot setting for the virtual host. Until I read this post, it reminded me to check all wildcard settings. The problem I had was slightly different from the one in the post.

In that post, the problem was from the wildcard setting on the ServerName. For me, I was missing a port number next to the wildcard when I was setting it at the VirtualHost directive for localhost. Everything works fine after the port number had been added.

Please don't make the same mistake as I did. Even you are using port 80, you should always put the port number next to it. Otherwise, your virtual DocumentRoot will NOT be recognized.

The followings are my virtual host settings in httpd-vhost.conf.

Incorrect Correct
NameVirtualHost *:9090

# Missing port number to localhost or the default site
<VirtualHost *>
  DocumentRoot "C:\servers\Apache Software Foundation\Apache2.2\htdocs"
  ServerName localhost

<Directory "h:/vhosts">
  Order Deny,Allow
  Allow from all
  Options Indexes FollowSymLinks

<VirtualHost *:9090>
   # Note: no wildcard supported in ServerName
   ServerName examples.local
   ErrorLog "logs/examples.local-error.log"
   CustomLog "logs/examples.local-access.log" common
   DocumentRoot "h:/vhosts/examples"
NameVirtualHost *:9090

# Port number is given to the localhost or the default site
<VirtualHost *:9090>
  DocumentRoot "C:\servers\Apache Software Foundation\Apache2.2\htdocs"
  ServerName localhost

<Directory "h:/vhosts">
  Order Deny,Allow
  Allow from all
  Options Indexes FollowSymLinks

<VirtualHost *:9090>
  # Note: no wildcard supported in ServerName
  ServerName examples.local
  ErrorLog "logs/examples.local-error.log"
  CustomLog "logs/examples.local-access.log" common
  DocumentRoot "h:/vhosts/examples"