Xojo Plugin

Check Internet Connectivity

See more Socket/SSL/TLS Examples

Demonstrates an efficient way to test for Internet connectivity. Xojo Plugin

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.")