(Xojo Plugin) Check Internet Connectivity

Demonstrates an efficient way to test for Internet connectivity.

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

Dim success As Boolean
success = False

Dim socket As New Chilkat.Socket
// 1. Use a reliable Anycast IP. 
//    8.8.8.8 (Google) or 1.1.1.1 (Cloudflare) are the industry standards.
Dim targetIp As String
targetIp = "8.8.8.8"

// 2. Use Port 53 (DNS). 
//    DNS servers typically listen on TCP Port 53 as well as UDP. 
//    (Alternatively, use port 443 if you suspect port 53 is blocked).
Dim port As Int32
port = 53

// 3. Disable SSL (0). 
//    We are not doing a handshake, just a TCP connection.
Dim ssl As Boolean
ssl = False

// 4. Short Timeout (1500ms).
//    If you can't reach Google in 1.5 seconds, the connection is 
//    likely too poor for practical use anyway.
Dim timeoutMs As Int32
timeoutMs = 1500

// Connect
success = socket.Connect(targetIp,port,ssl,timeoutMs)
If (success = False) Then
    System.DebugLog(socket.LastErrorText)
    Return
End If

success = socket.Close(10)

System.DebugLog("We have Internet connectivity.")