C # obtain lan ip segments

Static VoidMain ()
{
Arraylist list = getalllocalmachines ();
For(IntI =0; I <list. Count; I ++)
{
Console. writeline (list [I]);
}
Console. readkey ();
}
 

  //  First, ping the host of the network segment cyclically.
  //  Next, use the following function to obtain the list of IP addresses with responses in all the LAN.  
          Public   Static Arraylist getalllocalmachines ()
{
PROCESS p = New Process ();
P. startinfo. filename = "  Cmd.exe  " ;
P. startinfo. useshellexecute = False ;
P. startinfo. redirectstandardinput = True ;
P. startinfo. redirectstandardoutput = True ;
P. startinfo. redirectstandarderror =True ;
P. startinfo. createnowindow = True ;
P. Start (); p. standardinput. writeline ( "  ARP-  " );
P. standardinput. writeline ( "  Exit  " );
Arraylist list = New Arraylist ();
Streamreader reader = P. standardoutput;//  Read IP address. Mac ....  
              String Iphead = DNS. gethostbyname (DNS. gethostname (). Addresslist [ 0 ]. Tostring (). substring ( 0 , 3 );
 For ( String Line = reader. Readline (); line! = Null ; Line = reader. Readline ())
{
Line = line. Trim (); If (Line. startswith (iphead) & (line. indexof ( "  Dynamic  " )! =- 1 ))
{
 String IP = line. substring ( 0 , 15 ). Trim (); String MAC = line. substring (line. indexof ( "  -  " )- 2 ,0x11 ). Trim ();

List. Add (IP );
}
}
 Return List;
}