diff --git a/EduNetworkBuilder/IPAddress.cs b/EduNetworkBuilder/IPAddress.cs
index fa1f0fd..0819a71 100644
--- a/EduNetworkBuilder/IPAddress.cs
+++ b/EduNetworkBuilder/IPAddress.cs
@@ -277,6 +277,7 @@ namespace EduNetworkBuilder
         {
             string[] parts = original.Split('.');
             if (original == NB.ZeroIPString) return original;
+            if (parts.Count() == 4 && parts[0] == parts[1] && parts[1] == parts[2] && parts[2] == parts[3]) return original;
             bool done = false;
             List<string> toRandomize = new List<string>(parts);
             List<string> randomized = new List<string>();