IP address no good for WebClient Url?

  • Thread starter Thread starter Bryan
  • Start date Start date
B

Bryan

When I try to get a web page from an internal server, I have success
when I use the DNS name, but not when I use the raw IP address. The
first example works, the second does not. Why is this?

Example 1
--------------------------------------------------------------------------------------------------
' Get web page
Dim url As String = "http://brysrv:5004/"
Dim client As WebClient = New WebClient
Dim data As Stream = client.OpenRead(url)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = reader.ReadToEnd
reader.Close()
Console.WriteLine(str)

Example 2
--------------------------------------------------------------------------------------------------
' Get web page
Dim url As String = "http://10.0.45.67:5004/"
Dim client As WebClient = New WebClient
Dim data As Stream = client.OpenRead(url)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = reader.ReadToEnd
reader.Close()
Console.WriteLine(str)
 
When I try to get a web page from an internal server, I have success
when I use the DNS name, but not when I use the raw IP address. The
first example works, the second does not. Why is this?

Example 1
--------------------------------------------------------------------------------------------------
' Get web page
Dim url As String = "http://brysrv:5004/"
Dim client As WebClient = New WebClient
Dim data As Stream = client.OpenRead(url)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = reader.ReadToEnd
reader.Close()
Console.WriteLine(str)

Example 2
--------------------------------------------------------------------------------------------------
' Get web page
Dim url As String = "http://10.0.45.67:5004/"
Dim client As WebClient = New WebClient
Dim data As Stream = client.OpenRead(url)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = reader.ReadToEnd
reader.Close()
Console.WriteLine(str)
Click to expand...

Bryan,
Normally both of them should work (defining URI as address and as IP).
To test, try getting Google's data as examle as follows:

' Both works:
Example 1 works with using an IP as string
-------------------------------------
' Get web page
' That IP belongs to Google
Dim url As String = "http://74.125.77.104/"
Dim client As WebClient = New WebClient
Dim data As Stream = client.OpenRead(url)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = reader.ReadToEnd
reader.Close()
Console.WriteLine(str)


Example 2 for Google again which works with absolute web path:
--------------------------------------------
' Get web page
Dim url As String = "http://www.google.com"
Dim client As WebClient = New WebClient
Dim data As Stream = client.OpenRead(url)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = reader.ReadToEnd
reader.Close()
Console.WriteLine(str)


So, i think, just by looking at your code, in your example 2, it seems
you're trying to access an IP which resides on a restricted LAN area,
that is is needed to be forwarded through a router setting or kinda. I
beleive, if you set required rights and especially forward that IP
address with port 5004, you problem should be solved based on my
previous experiences.

HTH,

Onur Güzel
 
Bryan said:
When I try to get a web page from an internal server, I have success
when I use the DNS name, but not when I use the raw IP address. The
first example works, the second does not. Why is this?
Click to expand...

Is the web server using host headers for brysrv? That could stop a URL
written as the IP address from working.

Andrew
 
Is the web server using host headers for brysrv? That could stop a URL
written as the IP address from working.

Andrew
Click to expand...

The strangest thing is that I could connect to 10.0.45.67:5004 just
fine in my web browser. That's when I realized that maybe .Net is
pulling me internet settings from Internet Explorer. I use Firefox as
a browser, and it worked fine there. I checked my IE settings and saw
that I still had a proxy set up. I deleted the proxy settings and it
works now. I'm assuming that .Net uses IE internet settings?
 
The strangest thing is that I could connect to 10.0.45.67:5004 just
fine in my web browser.  That's when I realized that maybe .Net is
pulling me internet settings from Internet Explorer.  I use Firefox as
a browser, and it worked fine there.  I checked my IE settings and saw
that I still had a proxy set up.  I deleted the proxy settings and it
works now.  I'm assuming that .Net uses IE internet settings?
Click to expand...

Byran,
As stated in that link:
"The proxy is set by the system using configuration files and the
Internet Explorer Local Area Network settings" in WebClient.Proxy
property's documentation:
http://msdn.microsoft.com/en-us/library/system.net.webclient.proxy(VS.80).aspx

And also: "To specify that no proxy should be used, set the Proxy
property to the proxy instance returned by the GetEmptyWebProxy
method." seems stated.
GetEmptyWebProxy method:
http://msdn.microsoft.com/en-us/library/system.net.globalproxyselection.getemptywebproxy(VS.80).aspx

Hope that clarifies,

Onur Güzel


And also you stated
 
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