Verify if sendThrough is a local address.

https://github.com/2dust/v2rayN/issues/9562

v2rayN/ServiceLib/Common/Utils.cs

@@ -716,6 +716,18 @@ public class Utils
         return (endpoints, connections);
     }
 
+    public static bool IsLocalIP(string ipAddress)
+    {
+        if (!IPAddress.TryParse(ipAddress, out var targetAddress))
+        {
+            return false;
+        }
+
+        return NetworkInterface.GetAllNetworkInterfaces()
+               .SelectMany(ni => ni.GetIPProperties().UnicastAddresses)
+               .Any(ua => ua.Address.Equals(targetAddress));
+    }
+
     #endregion Speed Test
 
     #region Miscellaneous

v2rayN/ServiceLib/Services/CoreConfig/Singbox/SingboxConfigTemplateService.cs

@@ -83,6 +83,11 @@ public partial class CoreConfigSingboxService
         {
             return;
         }
+        if (!Utils.IsLocalIP(sendThrough))
+        {
+            return;
+        }
+
         foreach (var outbound in _coreConfig.outbounds ?? [])
         {
             outbound.inet4_bind_address = ShouldBindNet(outbound) ? sendThrough : null;

v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayConfigTemplateService.cs

@@ -176,6 +176,11 @@ public partial class CoreConfigV2rayService
         {
             return;
         }
+        if (!Utils.IsLocalIP(sendThrough))
+        {
+            return;
+        }
+
         foreach (var outbound in _coreConfig.outbounds ?? [])
         {
             outbound.sendThrough = ShouldBindNet(outbound) ? sendThrough : null;