diff --git a/EduNetworkBuilder/NetworkDevice.cs b/EduNetworkBuilder/NetworkDevice.cs
index 9ee8e88..c9eb29a 100644
--- a/EduNetworkBuilder/NetworkDevice.cs
+++ b/EduNetworkBuilder/NetworkDevice.cs
@@ -1393,8 +1393,17 @@ namespace EduNetworkBuilder
                     //If we are doing vlans, the vlan should match if we are doing management interface
                     //
                     //right now, just do it.
-                    nic.PrimaryInterface().myIP = new NB_IPAddress(newip, gateway._mask.ToIpString(), IPAddressType.ip);
-                    return true;
+                    NetworkInterface nif = nic.PrimaryInterface();
+                    if(nif == null)
+                    { //There are multiple interfaces, or there are no interfaces.
+                        //If multiple interfaces, try one with the specified vlan.
+                        nif = nic.InterfaceFromVlanTag(vlan);
+                    }
+                    if (nif != null)
+                    {
+                        nif.myIP = new NB_IPAddress(newip, gateway._mask.ToIpString(), IPAddressType.ip);
+                        return true;
+                    }
                 }
             }
             return false;