diff --git a/EduNetworkBuilder/NetworkDevice.cs b/EduNetworkBuilder/NetworkDevice.cs
index 6d61143..9cc760d 100644
--- a/EduNetworkBuilder/NetworkDevice.cs
+++ b/EduNetworkBuilder/NetworkDevice.cs
@@ -2927,10 +2927,10 @@ namespace EduNetworkBuilder
                 tPacket.MyStatus = PacketStatus.finished; //we have replaced it with other ones
                 return false;
             }
-            if (tPacket.OutboundIP == null || tPacket.OutboundIP.GetIP.ToIpString() == NB.ZeroIPString && tPacket.MyType != PacketType.dhcp_request)
+            if (tPacket.OutboundIP == null || tPacket.OutboundIP.IsZeroString() && tPacket.MyType != PacketType.dhcp_request)
             {
                 tPacket.OutboundIP = DestinationFromIP(dest,tPacket.OutboundNic);
-                if (tPacket.OutboundIP.GetIP.ToIpString() == NB.ZeroIPString)
+                if (tPacket.OutboundIP.IsZeroString())
                 {
                     if (tPacket.MyType == PacketType.dhcp_answer)
                     {
@@ -3017,7 +3017,7 @@ namespace EduNetworkBuilder
             {
                 nIF = nic.LocalInterface(toFind, null);
                 if (nIF != null) {
-                    if (nIF.myIP.GetIPString == NB.ZeroIPString)
+                    if (nIF.myIP.IsZeroString())
                         continue;
                     return nic;
                 }
@@ -3066,7 +3066,7 @@ namespace EduNetworkBuilder
                 {
                     foreach(NB_IPAddress ip in nic.IPAddressList())
                     {
-                        if (ip.GetIPString != NB.ZeroIPString && ip.GetIPString != NB.LoopbackIPString)
+                        if (!ip.IsZeroString() && !ip.IsLoopback())
                             return ip;
                     }
                 }
@@ -3093,7 +3093,7 @@ namespace EduNetworkBuilder
             if(Source != null)
             {
                 answer = LocalDeviceIP(Source);
-                if (answer != null && answer.GetIPString != NB.ZeroIPString)
+                if (answer != null && !answer.IsZeroString())
                     return answer;
             }
             //If we have a WAN Nic, use that first
@@ -3506,7 +3506,7 @@ namespace EduNetworkBuilder
             List<string> theStrings = new List<string>();
             foreach(NB_IPAddress ip in DHCPRanges)
             {
-                if (ip.GetIP.ToIpString() != "127.0.0.1")
+                if (!ip.IsLoopback())
                 {
                     if (WithAdditionalInfo)
                     {
@@ -3527,7 +3527,7 @@ namespace EduNetworkBuilder
             if (InterfaceIP == null) return null;
             foreach (NB_IPAddress ip in DHCPRanges)
             {
-                if (ip.GetIP.ToIpString() != "127.0.0.1" && InterfaceIP.IsLocal(ip))
+                if (!ip.IsLoopback() && InterfaceIP.IsLocal(ip))
                     return ip;
             }
             return null;