NullifyNetwork

My MSDN subscription is a bit broken at the moment unfortunately but it appears that Visual Studio 2005, .NET 2.0 and SQL 2005 are now all out and available to download!

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There is currently a threat of another large hurricane, this one is likely to make landfall and directly affect the area that my datacentre is located in (Houstan, Texas).

Although over 10,000 gallons of diesel are already on hand please ensure that queeg.nullify.net (located at Fortress ITX in New Jersey) is correctly set up to provide backup DNS and/or mail as needed.

Good luck to everyone staying behind in the datacentre in the face of the evacuation and the storm.

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As many of you know, I am a great fan of Opera. It has proved to be a highly secure, fast and powerful browser... Basically sites work and work well, and I can limit what they can and cannot do.

Now thanks to google changing their contract with opera when it comes to ad revenue from searches they can afford to make it 100% free.

Totally written from scratch and not based on Mosaic, Mozilla, IE or any other existing browser, it supports the following operating systems:

• Windows!
• Linux (a large number of distros AND a tar.gz)
• FreeBSD
• Solaris
• OS/2
• QNX
• And a large number of mobiles
• Mac

I still urge you to pay for premium support or whatever they call their subscription service in support for this great browser; but hey, if you can only pay by using it that's still good.

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Here's a static method that sets a printer as the default on a system, using the windows scripting host network stuff from C#.  It's here so I can look it up if anyone else asks in future since I couldn't easily find how to do this in C#...  (I know the exception handling is poor)

/// <summary>
/// Sets a default printer
/// </summary>
/// <param name="name"></param>
public static void SetDefaultPrinter(string name)
{
   try
   {
      //late bind to the wsh network com object
      //create an instance of a reflection type
      Type t = Type.GetTypeFromProgID("WScript.Network");
      //create an instance using the system activator, consuming the type
      Object o = Activator.CreateInstance(t);
      //invoke the method using the object we created
      t.InvokeMember("SetDefaultPrinter", System.Reflection.BindingFlags.InvokeMethod, null, o, new object[] {name});
   } 
   catch (Exception)
   {
      throw new Exception("Unable to set a default printer. The printer may not exist or the WScript.Network com object may have a problem.");
   }
}

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Hosted sites may start to experience routing issues, I've had several messages regarding them already. I suspect this is as the diesel runs out at telco sites in or around the Gulf Coast. Ev1 are doing a great job in Houston and there are no visible problems with connectivity over here in the UK/Europe. Permalink 

You can get a free license key for Opera (similar to firefox but commercial, faster, more secure, smaller and with a lot more features - like torrent support) at their 10th birthday party!. Permalink 

I've worked on this for a total of eight hours now inbetween everything else, but this is a sneak peak of a new product/freebie I am working on.  Take special note of the syntax editor...  I couldn't make richedit do what I wanted, so have been writing a syntax highlighting, intellisense supporting editor from scratch.

Eventually it will colour keywords and provide region support, but just showing text, the line numbers, a movable cursor and scroll bars was a milestone for me given it is done totally from scratch (even if the scrollbars are yet to be mouse enabled).

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I am still alive, and I must apologise for not posting anything to my blog but work has been eating most spare time whilst I've been getting some software out the door.

Hopefully work will no longer need so much of my time though, so I've started a few projects, one of which is a management studio for MSDE/SQL Express that allows profiling and various other features that I can't find anywhere else (some are in the toolset that Microsoft ship which isn't licensed for use with MSDE and isn't freely downloadable, but some aren't to be found anywhere afaik).  Just trying to add intellisense to my query execution part of the application now.  One bug to fix with stopping traces and I'll put a version up for download.

In unrelated news I've also enabled SPF on all the domains on xerxes using Mail Essentials from GFi, so those of you with e-mail on queeg are the last not to get it - hopefully debian has something to implement SPF with exim otherwise I'll need to write something to wrap it...

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Apologies for the lack of posting, but crunch mode at work whilst approaching beta has stopped me having time.  I'll probably get some more posted when it's over. Permalink 

This is good fun :) - a DHTML lemmings remake!

http://193.151.73.87/games/lemmings/index.html

It works on IE and Opera, so I have no doubt it'll work on Firefox/Mozilla.

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[ Taken from my post at the ms forums here: http://forums.microsoft.com/msdn/ShowPost.aspx?PostID=1014 ]

This is a bit bodged but I just hashed it together to see how easy it would be.  I thought back and could have just iterated over chararray, but it works which is what counts :D

/// <summary>
/// Represents a paragraph in English
/// </summary>
public abstract class Paragraph
{
/// <summary>
/// Convert a string in arbitrary case to English sentence capitalisation.
/// </summary>
/// <param name="text">The text to convert</param>
/// <returns>The paragraph of text</returns>
public static string ToSentenceCase(string text)
{
string temporary = text.ToLower();
string result = "";
while (temporary.Length>0)
{
string[] splitTemporary = splitAtFirstSentence(temporary);
temporary = splitTemporary[1];
if (splitTemporary[0].Length>0)
{
result += capitaliseSentence(splitTemporary[0]);
}
else
{
result += capitaliseSentence(splitTemporary[1]);
temporary = "";
}
}
return result;
}

private static string capitaliseSentence(string sentence)
{
string result = "";
while (sentence[0]==' ')
{
sentence = sentence.Remove(0,1);
result+=" ";
}
if (sentence.Length>0)
{
result += sentence.TrimStart().Substring(0, 1).ToUpper();
result += sentence.TrimStart().Substring(1, sentence.TrimStart().Length-1);
}
return result;
}

private static string[] splitAtFirstSentence(string text)
{
//these are the characters to start a new sentence after
int lastChar = text.IndexOfAny(new char[] {'.', ':', '\n', '\r', '!', '?'})+1;
if (lastChar==1)
{
lastChar = 0;
}
return new string[] { text.Substring(0, lastChar), text.Substring(lastChar, text.Length-lastChar) };
}
}

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[posted by me on the new Microsoft Forums at http://forums.microsoft.com/msdn/ShowPost.aspx?PostID=1266 ]

ProcessStartInfo pi = new ProcessStartInfo("cmd.exe", "/c dir");
pi.WindowStyle = ProcessWindowStyle.Hidden;
pi.RedirectStandardOutput = true;
pi.UseShellExecute = false;
Process p = Process.Start(pi);
p.WaitForExit();
p.Start();
TextReader t = p.StandardOutput;
MessageBox.Show(t.ReadToEnd());

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A colleague of mine at work was having some trouble with multithreading this morning and I suggested using asynchronous delegates (a delegate - something you can make do something else, in .NET this can be used as a form of trigger for starting any number of other methods that take and return the same parameters as it uses - that runs its methods in another thread).  This got me thinking so I decided to do a quick tutorial for anyone else who hasn't yet encountered this way of doing multithreading!

This is a short sharp example, and can be created in a simple form.  Remember not to try to update the form from the method being run by the delegate - if you want to do this you need to run a method that checks if InvokeRequired is true, then runs Invoke(myMethodsOwnName, new object {myFirstParameter, mySecondParameter, andSoOn}) if it is true, or does whatever UI editing is needed if false - so it is calling itself in the context of the user interface.

Anyway, on with the example!

/// <summary>
/// A button on the form
/// </summary>
private void button1_Click(object sender, System.EventArgs e)
{
   delegateInstance = new ExampleDelegate(beginThink);
   d.BeginInvoke(5, new AsyncCallback(finished), null);
}

This is where the program runs, a simple button that can be pressed.  We want to do something CPU intensive and blocking in here but instead we create an instance of a delegate and use the BeginInvoke method, the methods parameters come first (in this case 5) and then the callback method to run, and null for the object state.

/// <summary>
/// An instance of the delegate used to call a method asynchronously
/// </summary>
private ExampleDelegate delegateInstance;

/// <summary>
/// The example delegate
/// </summary>
private delegate string ExampleDelegate(int param);

/// <summary>
/// The example method that would block the user interface
/// </summary>
/// <param name="workOn">Number of seconds to block for</param>
/// <returns>Some string</returns>
private string beginThink(int workOn)
{
   Thread.Sleep(workOn*1000);
   return "Done";
}

This is our ficticious CPU intensive action, in this case we'll just block the thread by seeping for workOn seconds.

/// <summary>
/// The method that is called when work is done
/// </summary>
/// <param name="results">The results of the work</param>
private void finished(IAsyncResult results)
{
   MessageBox.Show(delegateInstance.EndInvoke(results));
}

And this is run when the asynchronous delegate is completed.  EndInvoke automatically return the same type as the delegate, (a string) which makes this nice and easy.

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Two days ago I got my new P7010 laptop, although it's hardly large enough to be called a laptop with a tiny 10.6" screen and being light enough to use with one hand whilst holding it with the other.

This is a review, or maybe a quick pass over it.  I'm typing it on it, but I won't be doing any serious coding on it due to some oddities with the keyboard layout (cursor keys, home and end which I regularly use are all one thing and need to use the fn key, which is in the wrong place being between ctrl and windows rather than on the far left.  And the delete key is in the top right.  I'll upload some pitctures to my public photo album shortly.)

There are several things nobody says when they talk about this laptop, and I wondered whether I should buy it because of this.  I'm very glad I did.

Firstly, it runs 3D games very well - if you use lower end settings.  This is to be expected with an Intel extreme graphics chip in it, and it's a tradeoff you need to make for the small size and long battery life.  I've yet to try Half-Life 2, but will update this post if I get a chance - probably on the weekend.

The 1.1Ghz processor easily beats a P4 3Ghz processor in appearing to be fast, it may not when encoding an MP3, or some other maths intensive task but it seems highly responsive - infact it appears as responsive as my Opteron workstation when using applications (although the drive is slower, however this is to be expected 10,000 rpm is physically a lot faster than 4200 rpm!).

Next, the screen everyone says is too high res for the size IS too high res for the size - but I've noticed that after using it for a short while I have easily gotten used to it.  Maybe support for 1024x640 would have been better than 1280x768, but this is at least future proofed for when Windows is fully vector based and will scale.  The screen is extremely crisp, clear and bright, though reflective and needing cleaning to prevent dust accumulating.  The screen is perfect for DVD's and videos - anything that scales..

It also has a slew of standard and not so standard features: Wireless, cd/dvd drive (in such a small laptop!) sd/mmc/memory stick reader, compact flash and seperate PCMCIA slot, two USB ports, video out, LAN, international modem, svideo and firewire.  An impressive battery life (so far tested to 6 hours 50 minutes real world use, with wifi on, without the second battery and with the screen not on the lowest brightness) rounds it off.  An impressive selection of modular options from Fujitsu Siements also makes this a very versatile device.

Missing features: GPRS/GSM, Camera, Bluetooth, serial and parallel ports, rear connectors (everything is conveniently on the sides), a top catch (although it seems to be sprung with some kind of mechanism that holds it shut and closes it quickly, but allows the screen to move freely to any angle), and dedicated graphics memory and card.

Overall I'm very impressed.  Apart from bluetooth most of the features are either not neded or an acceptable tradeoff for a device this small, the absence of bluetooth however should have meant the necessity of GPRS/GSM in a portable device - yet I am fine with wifi for the places I go.  As a large (book sized) PDA it serves well, as something to take notes on it beats a pda hands down - as you can see from this having been typed on it (I have no trouble touch typing on it).  As something to code on, we shall see.  As an entertainment device - well, you can watch dvd's, listen to music and play games - what more do you want?

I don't recommend anyone try to make such a small device their primary laptop or even worse primary computer without an external screen and keyboard/mouse however if you want small and portable because you travel or just don't want to carry a full laptop then this is the machine for you.

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I've been looking for a good .NET profiler and always been hit by large price tags, bloated software and general failure.

So, I was happy to discover the person that made NAnt also makes NProf!  http://nprof.sourceforge.net/Site/SiteHomeNews.html

I had to delete regasm.exe from his archive as it throws an exception for some reason, but when using the one on my system it registered fine and is now working - happily integrated into Visual Studio .NET :)

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Mere minutes after posting about VSA I notice a post on developer fusion by Mark Belles that is MUCH better at describing Microsoft.VSA - I suggest if your interest is peaked by my sample code you go have a look at his article!

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Have you ever wanted to be able to add scripting to your application?  So your users can write a script and you can have it run inside it, adding menus, etc. - like Microsoft Visual Basic for Applications allows in Office.

This is a preliminary article, I'll try to rewrite this but I just took a 20 minute break from work (need to have something done for tomorrow - so yes, still working at 10PM!  GRR) and finally managed to get scripting using Microsoft.VSA working from a C# application.  Apologies for the lack of tabs in the formatting and lack of explanation.

This is missing the ability to access anything in the running application - you need to register a global item (in the same way as code items and references are added) to do that - then it is exposed as an object inside the environment running the script.

Add references to Microsoft.VisualBasic.Vsa and Microsoft.Vsa (when I repost I'll be using JScript.NET - never fear!) and add the following using clauses:

using System.Reflection;

using Microsoft.Vsa;

using Microsoft.Win32;

And then add the following code to a button or similar (with a textbox to enter your script in) - this will create a scripting engine object, then run your script inside it.  The best test is to show a message using MessageBox.Show(""); (remember though, it's VB!)

ScriptEngine eng = new ScriptEngine();
eng.Start();
IVsaCodeItem c = eng.CreateCodeItem("ScriptItem");
c.SourceText = textBox1.Text; //Where this is a simple vb.net script with a class called Script and a Sub called Main
eng.Run();

And now, the main code chunk snippet that is the scripting engine:

public class ScriptEngine : IVsaSite
{
private IVsaEngine Engine;
public ScriptEngine()
{
Start();
}

public void Start()
{
try
{
Engine = new Microsoft.VisualBasic.Vsa.VsaEngine();
Engine.RootMoniker = "myapp://net.nullify.www/ScriptEngine";
Engine.Name = "vsaEngine";
Engine.RootNamespace = "VsaEngine";
Engine.Site = this;
Engine.InitNew();
CreateReference("Mscorlib.dll");
CreateReference("System.dll");
CreateReference("System.Windows.Forms.dll");
CreateReference("System.Data.dll");
CreateReference("System.Drawing.dll");
CreateReference("System.XML.dll");
}
catch (VsaException ex)
{
MessageBox.Show("Scripting engine error: "+ex.Message);
}
}

public IVsaReferenceItem CreateReference(string assemblyName)
{
IVsaReferenceItem item = (IVsaReferenceItem)Engine.Items.CreateItem(assemblyName, VsaItemType.Reference, VsaItemFlag.None);
item.AssemblyName = assemblyName;
return item;
}

public IVsaCodeItem CreateCodeItem(string itemName)
{
try
{
IVsaCodeItem item = (IVsaCodeItem)Engine.Items.CreateItem(itemName, VsaItemType.Code, VsaItemFlag.Class);
return item;
}
catch (VsaException ex)
{
MessageBox.Show("Problem creating the code item: "+ex.Message);
}
return null;
}

public void Run()
{
if (Engine.Compile())
{
Engine.Run();
Type type = Engine.Assembly.GetType("VsaEngine.Script");
MethodInfo method = type.GetMethod("Main");
method.Invoke(null, null);
}
}

#region IVsaSite Members

public object GetEventSourceInstance(string itemName, string eventSourceName)
{
// TODO: Add ScriptEngine.GetEventSourceInstance implementation
return this;
}

public object GetGlobalInstance(string name)
{
// TODO: Add ScriptEngine.GetGlobalInstance implementation
return null;
}

public void Notify(string notify, object info)
{
// TODO: Add ScriptEngine.Notify implementation
}

public bool OnCompilerError(IVsaError error)
{
MessageBox.Show("["+error.Line+"] Compiler error: "+error.Description);
return true;
}

public void GetCompiledState(out byte[] pe, out byte[] debugInfo)
{
// TODO: Add ScriptEngine.GetCompiledState implementation
pe = null;
debugInfo = null;
}

#endregion

}

And finally to test this you can use the following code:

imports System
imports System.Diagnostics

module Script
sub Main()
MessageBox.Show("Boo")
end sub
end module

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Robert Scoble is once again on his high horse about how RSS is amazing, comparing it to GUI versus CLI without looking at how primitive RSS itself is.  I propose it is around the other way, and that there is a successor for RSS out there.

RSS and ATOM as they are today WILL become extinct - or at least as limited as CLI's are today, with a small following; syndication and a standard way of reading content from a site without visiting the URI in a browser are going to be around for ages - I have no doubt about this.

The key is that someone needs to define a standard (e.g. - based on SOAP since we already happen to have it!) to query a 'feed' (now, we can term it a web service) for:

• New entries without content since a previous point in time
• New entries with content since a previous point in time
• All entries ever
• A specific web log entry
• Comments for an entry
• All comments since a point in time
• All comments ever
• An entry with comments at the same time
• Indicating you linked to a post or comment
• Posting a comment
• And to 'subscribe' where you are e-mailed or IM'd (or using msn alerts, or Jabber alerts or whatever) when there is an update.

It is inevitable, RSS uses too much bandwidth and gives duplicated content only when you request it which means you need to keep checking back (even if you get a HTTP message to say it hasn't changed).

A web service could make available only the necessary information in a smart way, it could track and push information in the background to notify when your aggregator needs to look at your RSS/ATOM data for new entries, and it could allow a full integration of the site with the aggregator for comments.

Robert needs to look forward, not back...

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http://me.sphere.pl/indexen.htm

MoonEdit is a multi user text editor, it lets two (or more) people simultaneously edit a single file, with multiple cursors, entry points and near real time collaboration.

I've been waiting for something like this for a while, after posting about it first, then a year or two later seeing SubEthaEdit for the Mac.  Hopefully someone (http://docsynch.sourceforge.net/) will come up with a plugin for Visual Studio.

(Links curtesy of ntk.net)

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I've noticed some google oddness, a lot of sites have suddenly dropped quite low in rankings. My DeveloperFusion profile page is now higher than my CV and this site!

Robert Scoble is now the SECOND Robert. No other search engine places THAT much weight on the Scobleizer.

And when searching for my current employer, Capita, a partner of theirs comes up first!

I have been trusting gigablast and even the new MSN search more than google recently, and I can't quite be sure what google have done to skew their current index.

(At least, on the search engine front. I am very impressed with some of google's current projects.)

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This is some code I wrote a little while back as an example OR mapper.  When inheriting from BaseDataDynamicEntity you can use the attribute [DataDynamic(“Name”)] to indicate the field name in the database and then use the class below to fetch data from the database or update it with any changes.

 

This is just an example though and doesn’t do the updating – but instead returns an array of string that can be used to look at what’s in the object now.  Return a set of SqlParameter’s and plug it into a stored procedure for a working example.

 

      public abstract class BaseDataDynamicEntity

      {

            /// <summary>

            /// An attribute to use to work out which properties have names that are in the database

            /// </summary>

            public class DataDynamic : Attribute

            {

                  public DataDynamic(string fieldName)

                  {

                        _fieldName = fieldName;

                  }

                  /// <summary>

                  /// The name of the field in the database

                  /// </summary>

                  public string FieldName

                  {

                        get

                        {

                              return _fieldName;

                        }

                  }

                  private string _fieldName = "";

            }

 

            /// <summary>

            /// Return a set of properties on this class as a demonstration of what is possible

            /// </summary>

            /// <returns></returns>

            public string[] ListDataProperties()

            {

                  Type t = this.GetType();

                  PropertyInfo[] p = t.GetProperties();

                  ArrayList properties = new ArrayList();

                  foreach (PropertyInfo pi in p)

                  {

                        if (pi.IsDefined(typeof(DataDynamic), true))

                        {

                              properties.Add(pi.Name+": "+pi.GetValue(this, null).ToString()); //could instead write these out to some parameters.

                        }

                  }

                  string[] values = new string[properties.Count];

                  properties.CopyTo(values);

                  return values;

            }

 

            /// <summary>

            /// Given an SqlDataReader from ExecuteReader, fetch a set of data and use it to fill the child objects properties

            /// </summary>

            /// <param name="dr"></param>

            public void SetDataProperties(SqlDataReader dr)

            {

                  while (dr.Read())

                  {

                        for (int i = 0; i<dr.FieldCount; i++)

                        {

                              setProperty(dr.GetName(i), dr.GetValue(i));

                        }

                  }

                  dr.Close();

            }

 

            private void setProperty(string name, object data)

            {

                  Type t = this.GetType();

                  PropertyInfo[] p = t.GetProperties();

                  foreach (PropertyInfo pi in p)

                  {

                        if (pi.IsDefined(typeof(DataDynamic), true)&&pi.CanWrite)

                        {

                              object[] fields = pi.GetCustomAttributes(typeof(DataDynamic), true);

                              foreach (DataDynamic d in fields)

                              {

                                    if (d.FieldName == name)

                                    {

                                          pi.SetValue(this, data, null);

                                    }

                              }

                             

                        }

                  }

            }

      }

 

And to use this, you do something like:

 

      public class NewsArticle: BaseDataDynamicEntity

      {

            private int _id = 5;

            /// <summary>

            /// The Id in the database

            /// </summary>

            [DataDynamic("id")]

            public int Id

            {

                  get

                  {

                        return _id;

                  }

                  set

                  {

                        _id = value;

                  }

            }

 

            private string _name = "Demo object";

            /// <summary>

            /// The name in the database

            /// </summary>

            [DataDynamic("subject")]

            public string Name

            {

                  get

                  {

                        return _name;

                  }

                  set

                  {

                        _name = value;

                  }

            }

      }

 

Which makes populating it as easy as:

 

SqlConnection sq = new SqlConnection("Data Source=(local);InitialCatalog=nullifydb;Integrated Security=SSPI;");

      sq.Open();

      SqlCommand sc = sq.CreateCommand();

      sc.CommandText = "SELECT TOP 1 * FROM newsarticle";

NewsArticle n = new NewsArticle();

      n.SetDataProperties(sc.ExecuteReader());

      sq.Close();

 

Obviously this is just an example, and you would want to use a DAL of some sort to do the data extraction, but integrating the DAL with the above technique should be fairly easy.

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This is something I posted to a mailing list in response to a question, but since posting it I've also been asked some questions which it answers - so, here is a VERY quick rundown of DNS:

> I basically need:

>

> (a) An overview of all the bits in the process – so I know I haven’t

> missed something obvious!

DNS is a tiered, cached method of querying some form of data, not necessarily a name, not necessarily an IP, not necessarily a text record, location, what the router for a network is, what the Kerberos/LDAP servers for a domain are, etc.

It uses the format:

Name dot

To distinguish a part, therefore (taking my own domain as an example) it is not really:

Nullify.net

But instead:

Nullify.net.

However the last dot is commonly left off for convenience incorrectly.  One or more domains controlled as a single entity on a server is called a 'zone'.

The bits that make up DNS from a practical standpoint consist of:

- A resolver

- A cache

- An authoritative server

The resolver is what exists on every persons computer, and on the ISP's nameservers along with a cache.  The resolver requests from the default DNS servers for the current dns 'zone' any desired records - in the case of a site that is in the root zone, or wants to query the root set of DNS servers there are a set of root servers, located at root-servers.net.  These can be extracted using dig, and have always stayed at the same IP - although one of these servers got a new multicast IP a short while ago.  Once a result (or NXDOMAIN, indicating there isn't a result) is retrieved - it is stored in the cache along with it's time to live (ttl).

The cache is the reason a small number of servers can support the whole Internet (obviously there's a lot behind the scenes, but the point still holds).  The vast majority of traffic is handled by the caches at every stage.  There will commonly be as many as four caches between an authoritative nameserver and a client.  The TTL maintains how long these hold a record of those results, and this is why DNS changes take so long.  The exact same cache is also used on a secondary nameserver, but rather than the TTL for records, the TTL for the zone itself is used.

An authoritative nameserver is a server that knows something itself.  It responds with a particular record for a particular domain - assuming anyone asks it.  There are both master and slave servers - a master holds the file that actually stores the data, the slave stores it in memory and relies on the TTL for the zone itself to decide how long it is authoritative.  The slave uses the zones serial number to decide whether a change has been made, and refreshes every time the refresh property of the SOA record for a zone has been expired.

>

> (b) An idea of how to set up the Windows Server as the primary nameserver

> (not sure if this is a good idea)

For windows you just create a zone and create the desired records.  From then on it will answer as a nameserver and can be queried by a machine looking at it as the default nameserver, or using nslookup/dig with it set as the default.

You then need to point a server on the internet for the domain you are adding a record to (say, net. Or com.!) to think it is the nameserver for a domain, and you require either an out of zone A record for it, or a glue record for it so that the IP of your own server can be resolved in order to go query it for the details of your domain!

To simplify this, for my domain I have a primary nameserver xerxes.nullify.net. at 2002:4262:b24a::4262:b24a and 66.98.178.74

This means that in order for xerxes to host nullify.net, the nameservers for net. Need to also contain both AAAA and A records for it.  A records resolve to a host.  (AAAA is ipv6, which you don't need to worry about yet).  You should request these records are created in advance for ALL nameservers that do not already have glue records.  The contact for the netblock the servers are hosted in may be contacted by some TLD providers, but net. And com. Don't do this.

Once you have glue records that have propagated to all the servers for the zone they are in, you need to ask them to delegate a hostname for you - this is your domain and results in your domain being set to use your nameservers - this is an NS record, and there will be one for each nameserver that knows that domain.

>

> (c) An idea of how to configure secondary nameservers

Create a secondary zone, pointed to yourdomain.tld. - note the last dot.  Then you need to make sure you secondary server has a glue record in your TLD and an A record in your domain, add an NS record to YOUR copy of the domain pointing to the nameserver, and finally have it added as an additional NS record to the TLD's servers.

>

> (d) An overview of how MX records work

An MX record is a mail exchanger record, when you send mail to a host the following happens:

- An attempt to resolve it as an A record occurs.

- An attempt to resolve it as an MX record occurs.

   - Each returned MX record points to an A record that is resolved.

      - Mail delivery is attempted at the A records in order of weighting.

The MX records take priority, to allow an A record to exist for a host, but that host not to receive mail.

MX records have a weighting, the lowest takes mail first, then if that is down the next highest, and so on.  MX records with the same weighting are attempted randomly.

If all MX records bounce, the message is queued but eventually bounces with a failure.  If there are no MX records, and no A record, the mail bounces instantly.  If there is an A record, delivery is attempted and on failure, it bounces instantly.

>

> (d) An overview of Reverse DNS records (and whether I need these)

>

You do need these to deliver mail, you also need these if you wish to run a netblock, since it can be revoked by the issuer if you fail to do so.

As the owner for a netblock, you also have rights to a second domain - in in-addr.arpa.

This domain follows the reverse of an IP, so it can be followed down through the ownership chain, for example if RIPE issued you the address space 192.168.0.0/24 you would have the zone:

0.168.192.in-addr.arpa.

You could set up www here, but it wouldn't be much use.  More use would be to set up a PTR record for your SMTP server, which is at 192.168.0.8:

8.0.168.192 PTR mymail.mydomain.tld.

Note that when working with DNS you really do need the final dot, otherwise it'll exist in your current domain.  This is the common cause of lots of problems like cname's not resolving correctly and instead trying to go to mymail.mydomain.tld.mydomain.tld.

A cname is an alias.

------

Records you need to know about are:

SOA - the actual domain as it is stored on your system.

A - a hostname to IP

PTR - an ip to hostname

SVR - a common service (e.g. - ldap and Kerberos to log in to active directory in a domain)

MX - mail exchanger

CNAME - an alias, or common name

TEXT - information or other details

You can explore from the client side and test everything is working by using nslookup.

To use nslookup, open a command prompt, define what record type you want, and type the name of the record.

For example:

C:\>nslookup

Default Server:  vex.nullify.net

Address:  192.168.0.5

> set type=a

> xerxes

Server:  vex.nullify.net

Address:  192.168.0.5

Name:    xerxes.nullify.net

Address:  66.98.178.74

> set type=ns

> nullify.net.

Server:  vex.nullify.net

Address:  192.168.0.5

nullify.net     nameserver = ns1.twisted4life.com

nullify.net     nameserver = queeg.nullify.net

nullify.net     nameserver = xerxes.nullify.net

queeg.nullify.net       internet address = 66.45.233.165

xerxes.nullify.net      internet address = 66.98.178.74

xerxes.nullify.net      AAAA IPv6 address = 2002:4262:b24a::4262:b24a

> set type=mx

> nullify.net

Server:  vex.nullify.net

Address:  192.168.0.5

nullify.net     MX preference = 20, mail exchanger = xerxes.nullify.net

nullify.net     MX preference = 30, mail exchanger = queeg.nullify.net

nullify.net     MX preference = 10, mail exchanger = firewall.nullify.net

nullify.net     nameserver = ns1.twisted4life.com

nullify.net     nameserver = queeg.nullify.net

nullify.net     nameserver = xerxes.nullify.net

firewall.nullify.net    internet address = 81.109.199.173

xerxes.nullify.net      internet address = 66.98.178.74

xerxes.nullify.net      AAAA IPv6 address = 2002:4262:b24a::4262:b24a

queeg.nullify.net       internet address = 66.45.233.165

> 

Feel free to use my domain to explore it if you want, it (should be) set up correctly, and everything is public info anyway.  http://www.demon.net/toolkit/internettools/ contains some useful tools to test your domain from outside your own network if you don't have access to an external machine.

Exploring from the client side gives a good idea what the server side setup will need to be.

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I don't normally talk about things like the Tsunami, or September 11. I let others who are much better qualified or more descriptive cover them and try not to clutter the net with more useless content, however with the deathtoll officially passing 125,000 confirmed dead - I have just one thing to say:

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I've had IPv6 in testing on xerxes.nullify.net (in Texas, US) for some time as xerxes.ipv6.nullify.net but have now finally enabled it on the main hostname since it has been stable and worked reliably. I've also got it working from home (Surrey, UK) and am working on queeg.nullify.net (now New Jersey, US).

If anyone has any problems viewing anything please let me know.

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Merry christmas and a happy new year everyone! Permalink 

This is possibly the best post I've seen on debugging .NET memory leaks (when the garbage collector isn't quite working as intended, or your program is keeping something alive longer than it should). Permalink 

You can do this using the OPENROWSET function in MS SQL Server, so:

SELECT * FROM OPENROWSET('MSDASQL', 'ConnectionString', 'SELECT * FROM mytable')

Which is great in a view for data consolidation - but even better is to remove the need for a connection string by connecting just once!

You can do this using sp_addlinkedserver and sp_addlinkedsrvlogin.  Requirements will change depending on what you want to connect to - if you need help with a particular one feel free to e-mail me.

You can then simply use the new 'server' you just set up as so:

SELECT * FROM OPENQUERY(servername, 'SELECT * FROM mytable')

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