diff --git a/ShareClipbrd/ShareClipbrd.Core.Tests/Services/AddressResolverTests.cs b/ShareClipbrd/ShareClipbrd.Core.Tests/Services/AddressResolverTests.cs
index 05a4640..574db74 100644
--- a/ShareClipbrd/ShareClipbrd.Core.Tests/Services/AddressResolverTests.cs
+++ b/ShareClipbrd/ShareClipbrd.Core.Tests/Services/AddressResolverTests.cs
@@ -52,12 +52,13 @@ public void UseAddressDiscoveryService_Valid_Address_Return_True_And_Id() {
         public void UseAddressDiscoveryService_When_Invalid_Ports_Throws_ArgumentException() {
             string id;
             int? mandatoryPort;
-            Assert.Throws<ArgumentException>(() => AddressResolver.UseAddressDiscoveryService("mdns:abcde:", out id, out mandatoryPort));
-            Assert.Throws<ArgumentException>(() => AddressResolver.UseAddressDiscoveryService("mdns:abcde: ", out id, out mandatoryPort));
+            Assert.Throws<ArgumentException>(() => AddressResolver.UseAddressDiscoveryService("mdns:abcde: 1", out id, out mandatoryPort));
+            Assert.Throws<ArgumentException>(() => AddressResolver.UseAddressDiscoveryService("mdns:abcde: 65535", out id, out mandatoryPort));
+
             Assert.Throws<ArgumentException>(() => AddressResolver.UseAddressDiscoveryService("mdns:abcde:-1", out id, out mandatoryPort));
             Assert.Throws<ArgumentException>(() => AddressResolver.UseAddressDiscoveryService("mdns:abcde:65536", out id, out mandatoryPort));
 
-            Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns::1", out id, out mandatoryPort));
+            Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns::", out id, out mandatoryPort));
             Assert.That(id, Is.Empty);
             Assert.That(mandatoryPort, Is.Null);
         }
@@ -67,9 +68,17 @@ public void UseAddressDiscoveryService_Returns_True_And_Empty_Id_If_Address_Is_N
             string id;
             int? mandatoryPort;
 
+            Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns:abcde:", out id, out mandatoryPort));
+            Assert.That(id, Is.EqualTo("abcde"));
+            Assert.That(mandatoryPort, Is.Null);
+
             Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns:", out id, out mandatoryPort));
             Assert.That(id, Is.Empty);
             Assert.That(mandatoryPort, Is.Null);
+
+            Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns::1", out id, out mandatoryPort));
+            Assert.That(id, Is.Empty);
+            Assert.That(mandatoryPort, Is.EqualTo(1));
         }
 
         [Test]
@@ -85,9 +94,6 @@ public void UseAddressDiscoveryService_Valid_Ports_And_Entire_Id_Extracting_Test
             Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns:abcde:65535", out id, out mandatoryPort));
             Assert.That(id, Is.EqualTo("abcde"));
             Assert.That(mandatoryPort, Is.EqualTo(65535));
-            Assert.IsTrue(AddressResolver.UseAddressDiscoveryService("mdns:abcde: 65535", out id, out mandatoryPort));
-            Assert.That(id, Is.EqualTo("abcde"));
-            Assert.That(mandatoryPort, Is.EqualTo(65535));
         }
     }
 }
diff --git a/ShareClipbrd/ShareClipbrd.Core/Services/AddressResolver.cs b/ShareClipbrd/ShareClipbrd.Core/Services/AddressResolver.cs
index 3598931..bc6288e 100644
--- a/ShareClipbrd/ShareClipbrd.Core/Services/AddressResolver.cs
+++ b/ShareClipbrd/ShareClipbrd.Core/Services/AddressResolver.cs
@@ -1,4 +1,5 @@
-using System.Net;
+using System.Globalization;
+using System.Net;
 
 namespace ShareClipbrd.Core.Services {
     public class AddressResolver {
@@ -11,17 +12,23 @@ static void MandatoryPort(ref string id, out int? mandatoryPort) {
                 mandatoryPort = null;
                 return;
             }
+            if(portStart == id.Length - 1) {
+                id = id[..portStart];
+                mandatoryPort = null;
+                return;
+            }
 
-            if(int.TryParse(id[(portStart + 1)..], out port)) {
-                try {
-                    _ = new IPEndPoint(IPAddress.Any, port);
-                    id = id[..portStart];
-                    mandatoryPort = port;
-                    return;
-                } catch(ArgumentOutOfRangeException) {
-                }
+            try {
+                port = int.Parse(id[(portStart + 1)..], NumberStyles.None, CultureInfo.InvariantCulture);
+                _ = new IPEndPoint(IPAddress.Any, port);
+                id = id[..portStart];
+                mandatoryPort = port;
+                return;
+            } catch(ArgumentOutOfRangeException) {
+                throw new ArgumentException($"Port not valid");
+            } catch(FormatException) {
+                throw new ArgumentException($"Port not valid");
             }
-            throw new ArgumentException("mdns port for the partner address is not needed");
         }
 
         public static bool UseAddressDiscoveryService(string address, out string id, out int? mandatoryPort) {
@@ -35,10 +42,6 @@ public static bool UseAddressDiscoveryService(string address, out string id, out
 
             MandatoryPort(ref s, out mandatoryPort);
             s = s.Trim();
-            if(string.IsNullOrEmpty(s)) {
-                id = string.Empty;
-                mandatoryPort = null;
-            }
             id = s;
             return true;
         }