app to app communication over network...

normal is <<<<<<<<Call Shell("net send [ComputerName] [Massage]")>>>>>>
Using mswinsck
in The Form add commandbutton and winsock control and two textboxex
<<<<<<<<<<<<<<<<<<<Client Side>>>>>>>>
Private Sub Command1_Click()
tcpClient.RemoteHost = "169.254.165.141"
tcpClient.Connect
End Sub
Private Sub tcpClient_DataArrival(ByVal bytesTotal As Long)
Dim strdata As String
tcpClient.GetData strdata
txtRec.Text = strdata
End Sub
Private Sub TxtSend_Change()
tcpClient.SendData TxtSend
End Sub
<<<<<<<<<<<<<<<<<<<<<Serverside>>>>>>>>>>>>>>>>>>>>>>>>>
Private Sub Command1_Click()
tcpServer.Listen
End Sub
Private Sub tcpServer_ConnectionRequest(ByVal requestID As Long)
If tcpServer.State <> sckClosed Then
tcpServer.Close
End If
tcpServer.Accept requestID
End Sub
Private Sub tcpServer_DataArrival(ByVal bytesTotal As Long)
Dim strdata As String
tcpServer.GetData strdata
TxtRec = strdata
End Sub
Private Sub txtSend_Change()
tcpServer.SendData txtSend
End Sub

if u use the second way yes it could be (if you write two pograms that uses from same port number you should change on (server and client) program port number to same

For getting ip adrees I think the simplest way is open run>cmd then press ok
((Open CommandPromt)) then type "Ping [Computer Name]" and then while your system is checking your connection between you and your remote connection(here is server) shows the Remote ip in Pinging......[computer Ip]
In Server Mode you should be always in open form[Listen Mode] if you`ve got dissconnected winsck should be close and then open [Listen Mode] again