diff --git a/option/rule_nested.go b/option/rule_nested.go
index c6038aad2..172165729 100644
--- a/option/rule_nested.go
+++ b/option/rule_nested.go
@@ -13,8 +13,8 @@ import (
 type nestedRuleDepthContextKey struct{}
 
 const (
-	routeRuleActionNestedUnsupportedMessage = "rule action is not supported in nested rules"
-	dnsRuleActionNestedUnsupportedMessage   = "DNS rule action is not supported in nested rules"
+	RouteRuleActionNestedUnsupportedMessage = "rule action is not supported in nested rules"
+	DNSRuleActionNestedUnsupportedMessage   = "DNS rule action is not supported in nested rules"
 )
 
 var (
@@ -27,11 +27,11 @@ func nestedRuleChildContext(ctx context.Context) context.Context {
 }
 
 func rejectNestedRouteRuleAction(ctx context.Context, content []byte) error {
-	return rejectNestedRuleAction(ctx, content, routeRuleActionKeys, routeRuleActionNestedUnsupportedMessage)
+	return rejectNestedRuleAction(ctx, content, routeRuleActionKeys, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func rejectNestedDNSRuleAction(ctx context.Context, content []byte) error {
-	return rejectNestedRuleAction(ctx, content, dnsRuleActionKeys, dnsRuleActionNestedUnsupportedMessage)
+	return rejectNestedRuleAction(ctx, content, dnsRuleActionKeys, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func nestedRuleDepth(ctx context.Context) int {
diff --git a/option/rule_nested_test.go b/option/rule_nested_test.go
index ca0ff32df..d5035891b 100644
--- a/option/rule_nested_test.go
+++ b/option/rule_nested_test.go
@@ -21,7 +21,7 @@ func TestRuleRejectsNestedDefaultRuleAction(t *testing.T) {
 			{"domain": "example.com", "outbound": "direct"}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestRuleRejectsNestedLogicalRuleAction(t *testing.T) {
@@ -41,7 +41,7 @@ func TestRuleRejectsNestedLogicalRuleAction(t *testing.T) {
 			}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestRuleRejectsNestedDefaultRuleZeroValueOutbound(t *testing.T) {
@@ -55,7 +55,7 @@ func TestRuleRejectsNestedDefaultRuleZeroValueOutbound(t *testing.T) {
 			{"domain": "example.com", "outbound": ""}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestRuleRejectsNestedDefaultRuleZeroValueRouteOption(t *testing.T) {
@@ -69,7 +69,7 @@ func TestRuleRejectsNestedDefaultRuleZeroValueRouteOption(t *testing.T) {
 			{"domain": "example.com", "udp_connect": false}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestRuleRejectsNestedLogicalRuleZeroValueAction(t *testing.T) {
@@ -88,7 +88,7 @@ func TestRuleRejectsNestedLogicalRuleZeroValueAction(t *testing.T) {
 			}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestRuleRejectsNestedLogicalRuleZeroValueRouteOption(t *testing.T) {
@@ -107,7 +107,7 @@ func TestRuleRejectsNestedLogicalRuleZeroValueRouteOption(t *testing.T) {
 			}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestRuleAllowsTopLevelLogicalAction(t *testing.T) {
@@ -137,7 +137,7 @@ func TestRuleLeavesUnknownNestedKeysToNormalValidation(t *testing.T) {
 		]
 	}`), &rule)
 	require.ErrorContains(t, err, "unknown field")
-	require.NotContains(t, err.Error(), routeRuleActionNestedUnsupportedMessage)
+	require.NotContains(t, err.Error(), RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleRejectsNestedDefaultRuleAction(t *testing.T) {
@@ -151,7 +151,7 @@ func TestDNSRuleRejectsNestedDefaultRuleAction(t *testing.T) {
 			{"domain": "example.com", "server": "default"}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleRejectsNestedLogicalRuleAction(t *testing.T) {
@@ -171,7 +171,7 @@ func TestDNSRuleRejectsNestedLogicalRuleAction(t *testing.T) {
 			}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleRejectsNestedDefaultRuleZeroValueServer(t *testing.T) {
@@ -185,7 +185,7 @@ func TestDNSRuleRejectsNestedDefaultRuleZeroValueServer(t *testing.T) {
 			{"domain": "example.com", "server": ""}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleRejectsNestedDefaultRuleZeroValueRouteOption(t *testing.T) {
@@ -199,7 +199,7 @@ func TestDNSRuleRejectsNestedDefaultRuleZeroValueRouteOption(t *testing.T) {
 			{"domain": "example.com", "disable_cache": false}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleRejectsNestedLogicalRuleZeroValueAction(t *testing.T) {
@@ -218,7 +218,7 @@ func TestDNSRuleRejectsNestedLogicalRuleZeroValueAction(t *testing.T) {
 			}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleRejectsNestedLogicalRuleZeroValueRouteOption(t *testing.T) {
@@ -237,7 +237,7 @@ func TestDNSRuleRejectsNestedLogicalRuleZeroValueRouteOption(t *testing.T) {
 			}
 		]
 	}`), &rule)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestDNSRuleAllowsTopLevelLogicalAction(t *testing.T) {
@@ -267,5 +267,5 @@ func TestDNSRuleLeavesUnknownNestedKeysToNormalValidation(t *testing.T) {
 		]
 	}`), &rule)
 	require.ErrorContains(t, err, "unknown field")
-	require.NotContains(t, err.Error(), dnsRuleActionNestedUnsupportedMessage)
+	require.NotContains(t, err.Error(), DNSRuleActionNestedUnsupportedMessage)
 }
diff --git a/route/rule/rule_action.go b/route/rule/rule_action.go
index 9f8ef945e..194fed39f 100644
--- a/route/rule/rule_action.go
+++ b/route/rule/rule_action.go
@@ -240,7 +240,7 @@ func (r *RuleActionRouteOptions) Descriptions() []string {
 		descriptions = append(descriptions, F.ToString("network-type=", strings.Join(common.Map(r.NetworkType, C.InterfaceType.String), ",")))
 	}
 	if r.FallbackNetworkType != nil {
-		descriptions = append(descriptions, F.ToString("fallback-network-type="+strings.Join(common.Map(r.NetworkType, C.InterfaceType.String), ",")))
+		descriptions = append(descriptions, F.ToString("fallback-network-type=", strings.Join(common.Map(r.FallbackNetworkType, C.InterfaceType.String), ",")))
 	}
 	if r.FallbackDelay > 0 {
 		descriptions = append(descriptions, F.ToString("fallback-delay=", r.FallbackDelay.String()))
diff --git a/route/rule/nested_action.go b/route/rule/rule_nested_action.go
similarity index 85%
rename from route/rule/nested_action.go
rename to route/rule/rule_nested_action.go
index 95bb57215..44e58839b 100644
--- a/route/rule/nested_action.go
+++ b/route/rule/rule_nested_action.go
@@ -8,11 +8,6 @@ import (
 	E "github.com/sagernet/sing/common/exceptions"
 )
 
-const (
-	routeRuleActionNestedUnsupportedMessage = "rule action is not supported in nested rules"
-	dnsRuleActionNestedUnsupportedMessage   = "DNS rule action is not supported in nested rules"
-)
-
 func ValidateNoNestedRuleActions(rule option.Rule) error {
 	return validateNoNestedRuleActions(rule, false)
 }
@@ -23,7 +18,7 @@ func ValidateNoNestedDNSRuleActions(rule option.DNSRule) error {
 
 func validateNoNestedRuleActions(rule option.Rule, nested bool) error {
 	if nested && ruleHasConfiguredAction(rule) {
-		return E.New(routeRuleActionNestedUnsupportedMessage)
+		return E.New(option.RouteRuleActionNestedUnsupportedMessage)
 	}
 	if rule.Type != C.RuleTypeLogical {
 		return nil
@@ -39,7 +34,7 @@ func validateNoNestedRuleActions(rule option.Rule, nested bool) error {
 
 func validateNoNestedDNSRuleActions(rule option.DNSRule, nested bool) error {
 	if nested && dnsRuleHasConfiguredAction(rule) {
-		return E.New(dnsRuleActionNestedUnsupportedMessage)
+		return E.New(option.DNSRuleActionNestedUnsupportedMessage)
 	}
 	if rule.Type != C.RuleTypeLogical {
 		return nil
diff --git a/route/rule/nested_action_test.go b/route/rule/rule_nested_action_test.go
similarity index 96%
rename from route/rule/nested_action_test.go
rename to route/rule/rule_nested_action_test.go
index 77ff29c7b..6923b3510 100644
--- a/route/rule/nested_action_test.go
+++ b/route/rule/rule_nested_action_test.go
@@ -68,7 +68,7 @@ func TestNewRuleRejectsNestedRuleAction(t *testing.T) {
 			},
 		},
 	}, false)
-	require.ErrorContains(t, err, routeRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, option.RouteRuleActionNestedUnsupportedMessage)
 }
 
 func TestNewDNSRulePreservesImplicitTopLevelDefaultAction(t *testing.T) {
@@ -133,7 +133,7 @@ func TestNewDNSRuleRejectsNestedRuleAction(t *testing.T) {
 			},
 		},
 	}, true, false)
-	require.ErrorContains(t, err, dnsRuleActionNestedUnsupportedMessage)
+	require.ErrorContains(t, err, option.DNSRuleActionNestedUnsupportedMessage)
 }
 
 func TestNewDNSRuleRejectsReplyRejectMethod(t *testing.T) {