Should be an easy Question for a good programmer

Hi,
Just wondering if anyone knows how to make an IP scanner,
A program that scanns 1 port on more than 1 IP and then
lists which IP's have that port open.

Thanks for any help

Hurgh

So it just scans 1 port? Have it send out anything, and if another program recieves it, it will send confermation back, then that program will know what computers are connected to that port.

I sort of tried that but it is not realy what I want to acheive (If what you say is the same as what I think I tried.) I want it to be something like the SubSeven or Netbus Ip Scanners you know so that you can set an IP range and a port to check and it will check all thoes IP's to see if that port is open then if it is open it will put it inot a list box.

any other thoughts?

Thanks anyway,


Hurgh

How about something like this...
It would check for web servers on port 80. the timeout is set for 2 seconds.

sorry for the haste with Dims and var names etc

Code:

---


Public Found As Boolean

Private Sub Command1_Click()

Range = "111.111.111."

For x = 0 To 255

    Found = False
    Winsock1.Close
    Winsock1.RemotePort = 80
    strng = Range & Trim(Str(x))
    Winsock1.RemoteHost = strng
    Winsock1.Connect
   
    Debug.Print "Checking ->  " & strng
   
    timed = Timer
   
    While (Found = False) And (Timer - timed < 2) ' Timout setting
        DoEvents
    Wend
   
Next
   
End Sub

Private Sub Winsock1_Connect()

    Found = True
    Debug.Print "FOUND: " & Winsock1.RemoteHostIP

End Sub

---

I just had a few more thoughts,

1. This is only checking TCP not UDP so that should be added.

2. You could speed this up a lot if you used a control array with about 5 - 10 elements. you could have a queuing function which passed the next address to each as it finished it's lookup. It would be nice to give a 3-4 second timout to the connections so a control array of the winsock would allow extra time to be given to each test yet speed the overall process.

To add udp you might have control arrays 1-4 checking UDP and 5-8 checking TCP, then split the range so that they don't check the same port together.

1-4 array checks 0-127 UDP
5-8 array checks 128-255 TCP

Then

1-4 array checks 128-255 UDP
5-8 array checks 0 - 127 TCP

At three seconds timout each it should only take 32 seconds to scan a class C address. (faster if it finds hosts quicker)

Here is A local and remote trojan port scanner. I believe it may be what your looking for.