diff --git a/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Common/IPAddress.cs b/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Common/IPAddress.cs
index 0d1b104f..b283060f 100644
--- a/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Common/IPAddress.cs
+++ b/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Common/IPAddress.cs
@@ -5,7 +5,7 @@ using System.Web;
 
 namespace WebsitePanel.EnterpriseServer {
 
-	public struct IPAddress {
+	public struct IPAddress : IComparable {
 		public Int128 Address;
 		public bool V6 { get; private set; }
 		public bool V4 { get { return !V6 || Null; } }
@@ -68,10 +68,19 @@ namespace WebsitePanel.EnterpriseServer {
             if (Null)
                 return "";
 			var s = new System.Text.StringBuilder();
-			if (!V6) {
-				var ipl = Address;
-				s.Append(String.Format("{0}.{1}.{2}.{3}", (ipl >> 24) & 0xFFL, (ipl >> 16) & 0xFFL, (ipl >> 8) & 0xFFL, (ipl & 0xFFL)));
-			} else if (!IsMask) {
+            if (!V6)
+            {
+                var ipl = Address;
+                if (IsMask)
+                {
+                    int digits = 32 - Cidr;
+                    ipl = (Int128.MaxValue << 1) | 0x1; // remove left sign bit
+                    ipl = ipl << digits;
+                }
+                s.Append(String.Format("{0}.{1}.{2}.{3}", (ipl >> 24) & 0xFFL, (ipl >> 16) & 0xFFL, (ipl >> 8) & 0xFFL, (ipl & 0xFFL)));
+            }
+            else if (!IsMask)
+            {
 				
 				var vals = new List<int>();
 				int i;
@@ -181,7 +190,20 @@ namespace WebsitePanel.EnterpriseServer {
 		}
 
 		public static implicit operator IPAddress(NullIPAddress a) { return new IPAddress { Null = true, Address = 0, Cidr = -1 }; }
-	}
+
+        public int CompareTo(object obj)
+        {
+            var a = this.Address;
+            var b = ((IPAddress)obj).Address;
+
+            if (a < b)
+                return 1;
+            else if (a > b)
+                return -1;
+            else
+                return 0;
+        }
+    }
 
 	public class NullIPAddress { }
 
diff --git a/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Virtualization/VirtualizationServerController.cs b/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Virtualization/VirtualizationServerController.cs
index d07c176f..e9eb4862 100644
--- a/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Virtualization/VirtualizationServerController.cs
+++ b/WebsitePanel/Sources/WebsitePanel.EnterpriseServer/Code/Virtualization/VirtualizationServerController.cs
@@ -3235,40 +3235,31 @@ namespace WebsitePanel.EnterpriseServer
             Trace.TraceInformation("Param - subnetMask: {0}", subnetMask);
 
             // start IP address
-            var startIp = IPAddress.Parse(startIPAddress);
-            var mask = IPAddress.Parse(subnetMask);
-
-            Trace.TraceInformation("Calculate initial value for lastAddress");
-            var lastAddress = (startIp & ~mask) - 1;
-            Trace.TraceInformation("Initial lastAddress: {0}", lastAddress.ToString());
+            var ip = IPAddress.Parse(startIPAddress) - 1;
 
             Trace.TraceInformation("Start looking for next available IP");
             foreach (var addr in ips.Keys)
             {
-                if ((addr - lastAddress) > 1)
+                if ((addr - ip) > 1)
                 {
                     // it is a gap
-                    Trace.TraceInformation("Gap");
                     break;
                 }
                 else
                 {
-                    lastAddress = addr;
-                    Trace.TraceInformation("New lastAddress: {0}", lastAddress.ToString());
+                    ip = addr;
                 }
             }
 
-            var genAddr = lastAddress + 1;
-            Trace.TraceInformation("Generated address: {0}", genAddr.ToString());
+            // final IP found
+            ip = ip + 1;
 
-            // convert to IP address
-            var ip = startIp & mask | genAddr;
             string genIP = ip.ToString();
             Trace.TraceInformation("Generated IP: {0}", genIP);
 
             // store in cache
             Trace.TraceInformation("Adding to sorted list");
-            ips.Add(genAddr, genIP);
+            ips.Add(ip, genIP);
 
             Trace.TraceInformation("Leaving GenerateNextAvailablePrivateIP()");
             return genIP;
@@ -3292,8 +3283,14 @@ namespace WebsitePanel.EnterpriseServer
         }
 
 		private static string GetPrivateNetworkSubnetMask(string cidr, bool v6) {
-			if (v6) return "/" + cidr;
-			else return IPAddress.Parse("/" + cidr).ToV4MaskString();
+            if (v6)
+            {
+                return "/" + cidr;
+            }
+            else
+            {
+                return IPAddress.Parse("/" + cidr).ToV4MaskString();
+            }
 		}
 
 		private static string GetSubnetMaskCidr(string subnetMask) {