diff --git a/cmd/server/main.go b/cmd/server/main.go
index 6850c1b..7ee6373 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -397,6 +397,11 @@ func createAndMountISO(size, mountpoint, charset string) error {
 }
 
 func initializeNetworkProtocol(forceProtocol string) (*net.Dialer, error) {
+	// Handle empty/default value
+	if forceProtocol == "" {
+		forceProtocol = "auto"
+	}
+	
 	switch forceProtocol {
 	case "ipv4":
 		return &net.Dialer{
diff --git a/hmac-file-server.pid b/hmac-file-server.pid
new file mode 100644
index 0000000..1906cf2
--- /dev/null
+++ b/hmac-file-server.pid
@@ -0,0 +1 @@
+564137
\ No newline at end of file
diff --git a/test_upload.txt b/test_upload.txt
deleted file mode 100644
index 74c4948..0000000
--- a/test_upload.txt
+++ /dev/null
@@ -1 +0,0 @@
-Hello, HMAC File Server! Do 17. Jul 18:05:48 CEST 2025