VS 2008 DNS.gethostentry Error ' No Such Host Is Known'
Sep 3, 2010
I have been trying to trace a list of urls by using the url to get the ip and then use that to assign it a country. When using DNS.gethostentry or even DNS.gethostbyname I get the following error:
SocketExceptionwascaught: No such host is known
Now I even tried fetching the url first using httpwebrequest to ensure the url is valid but the error keeps showing up regardless. I know there are a few urls that don't work but I thought my code would catch and continue.
Try
For Each prod In querylist
If myfetcher.getHtml(prod, userAgent, page) Then
prod = Regex.Replace(prod, "http://", "")
I have a very specific problem concerning Dns.GetHostEntry.A service uses Dns.GetHostEntry to retrieve all IP Adresses of a host, using the name of of the host. This has always worked fine. At a specific customer, Dns.GetHostEntry throws the "no such host is known" error when querying specific hosts. The problem only occurs when trying to resolve hosts that are on a different domain than the machine the service is installed on. The service has worked for quite some time, but recently is stopped working, throwing the "no such host is known" error (sadly, no stack trace is available). Nslookup works though, no problems there.The service in question is written in VB.NET, targetting the .NET Framwork 2.0.The comments in the MSDN entry for .NET 3.0 (http:[url]....aspx indictate that there may be a problem with the reverse DNS entries for the hosts, but I was not able to reproduce the problem on a test network, even with all reverse lookup zones deleted (there are more comments for other .NET Versions, all having similiar problems). [EDIT:] Even deliberatly addind a wrong PTR record does not make the problem occur on my test machine.[EDIT2:] The only thing that made the error come up was disconnecting the network adapter, and thereby making the DNS Server unavailable, even though the forward resolving still worked due to caching.So, my questions are: Under which conditions does GetHostEntry throw this specific error? Which resolution methods does it use? If I'm not mistaken it uses the unmanaged WinSock function getnameinfo (http:[url]....: "Name resolution can be by the Domain Name System (DNS), a local hosts file, or by other naming mechanisms".Any ideas why this suddenly fails for machines on the other domain (but not for machines on the same domain)?
I want to check if an IP address can be resolved to a hostname.I figured I would use System.Net.Dns.GetHostEntry as System.Net.Dns. GetHostByAddress is shown as obsolete in VS2008.
However,if I specify an invalid IP address to System.Net.Dns.GetHostEntry the HostName property equals the IP address I gave. If I use System.Net.Dns.GetHostByAddress it, rightly, gives a resolution error.I don't mind continuing to use System.Net.Dns. GetHostByAddress but is there any way to have System.Net.Dns.GetHostEntry throw an error if the IP address cannot be resolved to a hostname (other than by checking if the IP address given equals the hostname returned, I mean)
I wonder if it is possible to write and capture errors when running a script to PowerShell.In my case I am using the following code:[code]' add an extra command to transform the script output objects into nicely formatted strings' remove this line to get the actual objects that the script returns, for example, see the script "Get-Process" returns a collection.[code]
An error that arises when I take a vb project Visual Studio 2010 that works on my local machine to a server. How precisely would I work around it?
Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. review the specific error details below and modify your configuration file appropriately.
Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.
Source Error:
Line 24: ASP.NET to identify an incoming user. Line 25: --> Line 26: <authentication mode="Windows" /> Line 27: <!-- Line 28: The <customErrors> section enables configuration
Below error is thrown in a already opened program which connects to different database
A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)
Program details: code done using vb.net with MSSQL 2008 as back-end
Two instance of same exe where running simultaneously in same PC but error was thrown only by one instance Program uses both sqlconnection(ADO.NET) and ADODB connection(upgraded from VB6) and the error is thrown by both types of connection. If the error is due to network problem with the server then why few programs work fine? I am not able to trace the reason for this behavior of the program. Can I know why this error occurs and why only in few programs of same instance.
I want to get the absolute host name from a URL that's in the format of a string. So far I have done it like this:[code]I need the host without the www for comparision purposes.If I have two strings "url...m" and "url...m" I'm interested in only seeing that they are both on the domain "url...m". Is there some fairly simple way to do this?
Does someone know what api funtion to use for getting remote host name right now i use System.Net.Dns.GetHostName and the nbtstat -a function, but still have some computers that i dont get their host name but i do get their mac with send arp...so how cna i get their host names with an API call..
This is my code for dns.hostname ..
vb.net Dim myIPs3 As System.Net.IPHostEntry = Dns.GetHostEntry(hello) Dim newhost3 As String = myIPs3.HostName
i want to add WPF Control to my windows forms application so i need to use element host but i couldn't find WPF Interoperability tab so i tried to add the reference and then add the control but i got this error why? and btw i tried also in C# and i got the same problem
I am working on an addin/plugin for CAD software called Solidworks. I use it to batch process files (print, save, etc). One thing I'd like to add is a form that contains a stop button to stop the loop. The problem is that even if I use a background worker like I normally would for a standalone application, it still locks up when Solidworks is processing files. That's just normal operation for the program, the UI freezes when doing a cpu intensive operation such as loading or saving files, regardless of how I write my plugin. So my limited attempts at threading to get a form that won't freeze have been unsuccessful so far.
I read some posts in the vb.net forum for how to modify your host file on your computer adding the domain website to block. this worked great. Then i went to a website such as vtunnel.com and was able to view the blocked website through it. So to still block it I need to add [url]... to the host site as well as any others?
I'm building an Expandable Groupbox control (source will be available in the codebank if I finish it), which is basically a groupbox with a [-] or [+] button to the left which allows the user to expand/contract it.
I've got it working pretty well, but now I want the user to be able to click the button in the designer to expand/contract the groupbox, rather than having to find the Expanded property in the property list every time. The ExpandableGroupbox control is just a UserControl with two panels (header and container), with an actual Button and a label for the text in the header panel. I know how to enable the user to click the button, even in the designer (this is done using WndMsg's and stuff, don't really understand that but it works!).
Now, there is one problem. When the button is clicked during design-time, the control is contracted (it's size changes), but the designer is not notified of this change. The selection rectangle remains as if the control size never changed, which is very confusing to the user. It only changes to the correct size after I select something else, and then select it again: At the moment, when the button is clicked it raises an event called Expand. I thought I could have my Designer class listen for that event, and refresh the selection service when it fires. I can get the control the designer is designing simply with the "Control" member.
Now here's the problem: Obviously I need to attach the Expand event using AddHandler, and I can see only one time to do that: in the constructor of the Designer.
So I tried it:
vb.net Public Class ExpandableGroupboxDesigner Inherits System.Windows.Forms.Design.ParentControlDesigner Public Sub New()
[Code].....
1. Can you see any other way to listen for the event? There is no 'control initialized' event or something I can use where I can attach the event as far as I know.
2. How do I refresh the selection service in the first place??
I have a website has already hosted on EasyCgi (suppose that it's called website1). I have to host another one (website2). So I created a folder called "website2" under the website1 root folder. then I FTP all the content of website2 to the "website2" folder.
How can I dynamically create a host name in ASP.NET? Like if people come to my site, I want to be able to dynamically create them a .Mysite.Com host name. I've seen this done at other sites before but can't seem to find documation on how to do it.
i need some help i want to create a chat but how to make it like you have winsock but are there none others and i got also a question im planning to buy a domain and if u use the dedicated ip can i host my chat then of that ip
I'm making a winforms app in vb.net that connects to a mysql database on my webserver to read and write data, this all works fine.But i have to allow the users ip to remote connect to the database.Is it possible to give everyone access to the database? The user account will not have all rights an the data isn't very important if it got lost.The user account and connection details are hard coded.
I need to get the host out of the Request object. Which property should I use and why?
From MSDN:Uri.DnsSafeHost Property A String that contains the unescaped host part of the URI that is suitable for DNS resolution; or the original unescaped host string, if it is already suitable for resolution.
vs
Uri.Host Property A String that contains the host name. This is usually the DNS host name or IP address of the server.
My testing has been with the ASP.NET Development Server. Both of these always return localhost. Even when I put in 127.0.0.1, both return localhost.Reading on, the DnsSafeHost property will handle IPv6 addresses, as well as Unicode to ASCII conversion if needed. It can also account for IRI and IDN. Even though I currently don't care about these things, should I just use the DnsSafeHost property to be safe?
In my ignorance, I thought I could subscribe to any host, so I chose hostmonster, and copy files from Visual Web Developer to it, thereby creating my first website. Wrong! Hostmonster is linux-based, so the files won't copy without assigning an index page at the site. The rep at the host said that linux doesn't read the language(s) I've been using to develop pages, Visual Basic and C#.
How can I set a host IP address and port.. and then detect if the port is open (accepting connections)or closed (denying connections)I came across this while searching, but it doesn't seem to function all that well..Using the port 80 and the host [URL] The result it gave me was closed... which is obviously wrong.So what can I do?Code: ( I have also imported "System.Net" and "System.Net.Sockets" )
Dim host As String = "www.google.com" Dim port As Integer = 80 Dim addr As IPAddress = CType(Dns.GetHostAddresses(host)(0), IPAddress)
