diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/AllowedEntityConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/AllowedEntityConfig.java
index 6e6663c..ee4042c 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/AllowedEntityConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/AllowedEntityConfig.java
@@ -23,7 +23,7 @@
  */
 public abstract class AllowedEntityConfig<S> extends Config<S> {
 
-    private static final String ALLOWED = "allowed";
+    protected static final String ALLOWED = "allowed";
 
     /**
      * Indicates whether the element is allowed for admission into the control
diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/BasicDeviceConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/BasicDeviceConfig.java
index afde9a9..add8cf3 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/BasicDeviceConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/BasicDeviceConfig.java
@@ -21,11 +21,17 @@
 /**
  * Basic configuration for network infrastructure devices.
  */
-public class BasicDeviceConfig extends BasicElementConfig<DeviceId> {
+public final class BasicDeviceConfig extends BasicElementConfig<DeviceId> {
 
-    public static final String TYPE = "type";
-    public static final String DRIVER = "driver";
-    public static final String MANAGEMENT_ADDRESS = "managementAddress";
+    private static final String TYPE = "type";
+    private static final String DRIVER = "driver";
+    private static final String MANAGEMENT_ADDRESS = "managementAddress";
+
+    @Override
+    public boolean isValid() {
+        return hasOnlyFields(ALLOWED, NAME, LATITUDE, LONGITUDE, RACK_ADDRESS, OWNER,
+                             TYPE, DRIVER, MANAGEMENT_ADDRESS);
+    }
 
     /**
      * Returns the device type.
@@ -85,6 +91,6 @@
     }
 
     // TODO: device port meta-data to be configured via BasicPortsConfig
-    // TODO: device credentials/keys
+    // TODO: device credentials/keys; in a separate config
 
 }
diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/BasicElementConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/BasicElementConfig.java
index 7b3248c..10d753b 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/BasicElementConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/BasicElementConfig.java
@@ -22,13 +22,13 @@
  */
 public abstract class BasicElementConfig<S> extends AllowedEntityConfig<S> {
 
-    public static final String NAME = "name";
+    protected static final String NAME = "name";
 
-    public static final String LATITUDE = "latitude";
-    public static final String LONGITUDE = "longitude";
+    protected static final String LATITUDE = "latitude";
+    protected static final String LONGITUDE = "longitude";
 
-    public static final String RACK_ADDRESS = "rackAddress";
-    public static final String OWNER = "owner";
+    protected static final String RACK_ADDRESS = "rackAddress";
+    protected static final String OWNER = "owner";
 
     protected static final double DEFAULT_COORD = -1.0;
 
diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/BasicHostConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/BasicHostConfig.java
index 9294631..8429630 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/BasicHostConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/BasicHostConfig.java
@@ -19,68 +19,62 @@
 import org.onlab.packet.IpAddress;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.HostId;
+
 import java.util.HashSet;
 import java.util.Set;
 
+import static org.onosproject.net.config.basics.AllowedEntityConfig.ALLOWED;
+
 /**
  * Basic configuration for network end-station hosts.
  */
-public class BasicHostConfig extends BasicElementConfig<HostId> {
+public final class BasicHostConfig extends BasicElementConfig<HostId> {
+
     private static final String IPS = "ips";
     private static final String LOCATION = "location";
 
     @Override
     public boolean isValid() {
-        return hasOnlyFields(IPS, LOCATION) &&
-                this.location() != null &&
-                this.ipAddresses() != null;
+        // Location and IP addresses can be absent, but if present must be valid.
+        this.location();
+        this.ipAddresses();
+        return hasOnlyFields(ALLOWED, NAME, LATITUDE, LONGITUDE, RACK_ADDRESS, OWNER,
+                             IPS, LOCATION);
     }
 
     /**
-     * Gets location of the host.
+     * Returns location of the host.
      *
-     * @return location of the host. Or null if not specified with correct format.
+     * @return location of the host or null if not set
+     * @throws IllegalArgumentException if not specified with correct format
      */
     public ConnectPoint location() {
         String location = get(LOCATION, null);
-
-        if (location != null) {
-            try {
-                return ConnectPoint.deviceConnectPoint(location);
-            } catch (Exception e) {
-                return null;
-            }
-        }
-        return null;
+        return location != null ? ConnectPoint.deviceConnectPoint(location) : null;
     }
 
     /**
      * Sets the location of the host.
      *
-     * @param location location of the host.
-     * @return the config of the host.
+     * @param location location of the host or null to unset
+     * @return the config of the host
      */
     public BasicHostConfig setLocation(String location) {
         return (BasicHostConfig) setOrClear(LOCATION, location);
     }
 
     /**
-     * Gets IP addresses of the host.
+     * Returns IP addresses of the host.
      *
-     * @return IP addresses of the host. Or null if not specified with correct format.
+     * @return IP addresses of the host or null if not set
+     * @throws IllegalArgumentException if not specified with correct format
      */
     public Set<IpAddress> ipAddresses() {
         HashSet<IpAddress> ipAddresses = new HashSet<>();
         if (object.has(IPS)) {
             ArrayNode ipNodes = (ArrayNode) object.path(IPS);
-            try {
-                ipNodes.forEach(ipNode -> {
-                    ipAddresses.add(IpAddress.valueOf(ipNode.asText()));
-                });
-                return ipAddresses;
-            } catch (Exception e) {
-                return null;
-            }
+            ipNodes.forEach(n -> ipAddresses.add(IpAddress.valueOf(n.asText())));
+            return ipAddresses;
         }
         return null;
     }
@@ -88,8 +82,8 @@
     /**
      * Sets the IP addresses of the host.
      *
-     * @param ipAddresses IP addresses of the host.
-     * @return the config of the host.
+     * @param ipAddresses IP addresses of the host or null to unset
+     * @return the config of the host
      */
     public BasicHostConfig setIps(Set<IpAddress> ipAddresses) {
         return (BasicHostConfig) setOrClear(IPS, ipAddresses);
diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/BasicLinkConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/BasicLinkConfig.java
index ed807b8..0ad851a 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/BasicLinkConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/BasicLinkConfig.java
@@ -26,19 +26,19 @@
 /**
  * Basic configuration for network infrastructure link.
  */
-public class BasicLinkConfig extends AllowedEntityConfig<LinkKey> {
+public final class BasicLinkConfig extends AllowedEntityConfig<LinkKey> {
 
-    public static final String TYPE = "type";
-    public static final String METRIC = "metric";
-    public static final String LATENCY = "latency";
-    public static final String BANDWIDTH = "bandwidth";
-    public static final String IS_DURABLE = "durable";
+    private static final String TYPE = "type";
+    private static final String METRIC = "metric";
+    private static final String LATENCY = "latency";
+    private static final String BANDWIDTH = "bandwidth";
+    private static final String IS_DURABLE = "durable";
 
     @Override
     public boolean isValid() {
-        return hasOnlyFields(TYPE, METRIC, LATENCY, BANDWIDTH, IS_DURABLE) &&
-                isNumber(METRIC, OPTIONAL) && isNumber(LATENCY, OPTIONAL) &&
-                isNumber(BANDWIDTH, OPTIONAL);
+        return hasOnlyFields(ALLOWED, TYPE, METRIC, LATENCY, BANDWIDTH, IS_DURABLE) &&
+                isBoolean(ALLOWED, OPTIONAL) && isNumber(METRIC, OPTIONAL) &&
+                isNumber(LATENCY, OPTIONAL) && isNumber(BANDWIDTH, OPTIONAL);
     }
 
     /**
diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/OpticalPortConfig.java b/core/api/src/main/java/org/onosproject/net/config/basics/OpticalPortConfig.java
index dfb494d..7a1b801 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/OpticalPortConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/OpticalPortConfig.java
@@ -23,11 +23,13 @@
 
 import com.fasterxml.jackson.databind.JsonNode;
 
+import static org.onosproject.net.config.Config.FieldPresence.OPTIONAL;
+
 
 /**
  * Configurations for an optical port on a device.
  */
-public class OpticalPortConfig extends Config<ConnectPoint> {
+public final class OpticalPortConfig extends Config<ConnectPoint> {
     // optical type {OMS, OCH, ODUClt, fiber}
     public static final String TYPE = "type";
 
@@ -42,6 +44,12 @@
     // **Linc-OE : remove if it's not needed after all.**
     public static final String SPEED = "speed";
 
+    @Override
+    public boolean isValid() {
+        return hasOnlyFields(TYPE, NAME, PORT, STATIC_PORT, STATIC_LAMBDA, SPEED) &&
+                isNumber(STATIC_LAMBDA, OPTIONAL) && isNumber(SPEED, OPTIONAL);
+    }
+
     /**
      * Returns the Enum value representing the type of port.
      *