diff --git a/common/config.go b/common/config.go
index 8a424bcf..a01438f4 100644
--- a/common/config.go
+++ b/common/config.go
@@ -311,16 +311,24 @@ func (f *I2PConfig) DoZero() string {
 
 // formatConfigPair creates a configuration string for inbound/outbound pairs
 func (f *I2PConfig) formatConfigPair(direction, property string, value interface{}) string {
+	var valueStr string
 	switch v := value.(type) {
 	case int:
-		return fmt.Sprintf("%s.%s=%d", direction, property, v)
+		if v == 0 {
+			return "" // Skip zero values to avoid duplicates
+		}
+		valueStr = strconv.Itoa(v)
 	case string:
-		return fmt.Sprintf("%s.%s=%s", direction, property, v)
+		if v == "" {
+			return ""
+		}
+		valueStr = v
 	case bool:
-		return fmt.Sprintf("%s.%s=%t", direction, property, v)
+		valueStr = strconv.FormatBool(v)
 	default:
 		return ""
 	}
+	return fmt.Sprintf("%s.%s=%s", direction, property, valueStr)
 }
 
 func (f *I2PConfig) InboundLength() string {
diff --git a/common/config_test.go b/common/config_test.go
index 0c8e2889..db7abfd5 100644
--- a/common/config_test.go
+++ b/common/config_test.go
@@ -1,6 +1,7 @@
 package common
 
 import (
+	"strings"
 	"testing"
 )
 
@@ -158,3 +159,38 @@ func TestLeaseSetSettings_Formatting(t *testing.T) {
 		})
 	}
 }
+
+func TestTunnelConfigNoDuplicates(t *testing.T) {
+	cfg := &I2PConfig{
+		InLength:    3,
+		OutLength:   3,
+		InQuantity:  2,
+		OutQuantity: 2,
+	}
+
+	config := cfg.TunnelConfig()
+	params := strings.Split(config, " ")
+
+	// Verify no duplicate parameters
+	seen := make(map[string]bool)
+	for _, param := range params {
+		if seen[param] {
+			t.Errorf("Duplicate parameter found: %s", param)
+		}
+		seen[param] = true
+	}
+
+	// Verify expected parameters present
+	expectedParams := []string{
+		"inbound.length=3",
+		"outbound.length=3",
+		"inbound.quantity=2",
+		"outbound.quantity=2",
+	}
+
+	for _, expected := range expectedParams {
+		if !strings.Contains(config, expected) {
+			t.Errorf("Missing expected parameter: %s", expected)
+		}
+	}
+}