diff --git a/net/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderBroker.java b/net/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderBroker.java
index a783fec..ad1e0ab 100644
--- a/net/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderBroker.java
+++ b/net/api/src/main/java/org/onlab/onos/net/provider/AbstractProviderBroker.java
@@ -38,10 +38,9 @@
     public synchronized void unregister(P provider) {
         checkNotNull(provider, "Provider cannot be null");
         S service = services.get(provider);
-        checkArgument(service != null, "Provider %s not registered", provider.id());
-        if (service instanceof AbstractProviderService) {
+        if (service != null && service instanceof AbstractProviderService) {
             ((AbstractProviderService) service).invalidate();
+            services.remove(provider);
         }
-        services.remove(provider);
     }
 }
diff --git a/net/api/src/main/java/org/onlab/onos/net/provider/ProviderBroker.java b/net/api/src/main/java/org/onlab/onos/net/provider/ProviderBroker.java
index a8e294e..438fdb7 100644
--- a/net/api/src/main/java/org/onlab/onos/net/provider/ProviderBroker.java
+++ b/net/api/src/main/java/org/onlab/onos/net/provider/ProviderBroker.java
@@ -13,6 +13,7 @@
      *
      * @param provider provider to be registered
      * @return provider service for injecting information into core
+     * @throws java.lang.IllegalArgumentException if the provider is registered already
      */
     S register(P provider);
 
@@ -20,6 +21,9 @@
      * Unregisters the supplied provider. As a result the previously issued
      * provider service will be invalidated and any subsequent invocations
      * of its methods may throw {@link java.lang.IllegalStateException}.
+     * <p/>
+     * Unregistering a provider that has not been previously registered results
+     * in a no-op.
      *
      * @param provider provider to be unregistered
      */
diff --git a/net/core/pom.xml b/net/core/pom.xml
index 30f6e12..0ceaa17 100644
--- a/net/core/pom.xml
+++ b/net/core/pom.xml
@@ -12,10 +12,14 @@
     </parent>
 
     <artifactId>onos-core</artifactId>
-    <packaging>bundle</packaging>
+    <packaging>pom</packaging>
 
     <description>ONOS network control core subsystems</description>
 
+    <modules>
+        <module>trivial</module>
+    </modules>
+
     <dependencies>
         <dependency>
             <groupId>org.onlab.onos</groupId>
diff --git a/net/core/trivial/pom.xml b/net/core/trivial/pom.xml
new file mode 100644
index 0000000..d4998ba
--- /dev/null
+++ b/net/core/trivial/pom.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-trivial</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS network control trivial implementations of core subsystems</description>
+
+</project>
diff --git a/net/core/src/main/java/org/onlab/onos/net/impl/GreetManager.java b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/GreetManager.java
similarity index 96%
rename from net/core/src/main/java/org/onlab/onos/net/impl/GreetManager.java
rename to net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/GreetManager.java
index 65a42bc..2b01396 100644
--- a/net/core/src/main/java/org/onlab/onos/net/impl/GreetManager.java
+++ b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/GreetManager.java
@@ -1,4 +1,4 @@
-package org.onlab.onos.net.impl;
+package org.onlab.onos.net.trivial.impl;
 
 import com.google.common.collect.ImmutableSet;
 import org.apache.felix.scr.annotations.Activate;
diff --git a/net/core/src/main/java/org/onlab/onos/net/impl/SimpleDeviceManager.java b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleDeviceManager.java
similarity index 98%
rename from net/core/src/main/java/org/onlab/onos/net/impl/SimpleDeviceManager.java
rename to net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleDeviceManager.java
index dc18065..53d4ed9 100644
--- a/net/core/src/main/java/org/onlab/onos/net/impl/SimpleDeviceManager.java
+++ b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleDeviceManager.java
@@ -1,4 +1,4 @@
-package org.onlab.onos.net.impl;
+package org.onlab.onos.net.trivial.impl;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
diff --git a/net/core/src/main/java/org/onlab/onos/net/impl/SomeOtherComponent.java b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SomeOtherComponent.java
similarity index 95%
rename from net/core/src/main/java/org/onlab/onos/net/impl/SomeOtherComponent.java
rename to net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SomeOtherComponent.java
index c53ab04..e040643 100644
--- a/net/core/src/main/java/org/onlab/onos/net/impl/SomeOtherComponent.java
+++ b/net/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SomeOtherComponent.java
@@ -1,4 +1,4 @@
-package org.onlab.onos.net.impl;
+package org.onlab.onos.net.trivial.impl;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
diff --git a/net/core/src/main/javadoc/org/onlab/onos/net/impl/package.html b/net/core/trivial/src/main/javadoc/org/onlab/onos/net/trivial/impl/package.html
similarity index 100%
rename from net/core/src/main/javadoc/org/onlab/onos/net/impl/package.html
rename to net/core/trivial/src/main/javadoc/org/onlab/onos/net/trivial/impl/package.html
diff --git a/net/core/src/test/java/org/onlab/onos/net/impl/GreetManagerTest.java b/net/core/trivial/src/test/java/org/onlab/onos/net/trivial/impl/GreetManagerTest.java
similarity index 94%
rename from net/core/src/test/java/org/onlab/onos/net/impl/GreetManagerTest.java
rename to net/core/trivial/src/test/java/org/onlab/onos/net/trivial/impl/GreetManagerTest.java
index 9c05f20..3bbffde 100644
--- a/net/core/src/test/java/org/onlab/onos/net/impl/GreetManagerTest.java
+++ b/net/core/trivial/src/test/java/org/onlab/onos/net/trivial/impl/GreetManagerTest.java
@@ -1,4 +1,4 @@
-package org.onlab.onos.net.impl;
+package org.onlab.onos.net.trivial.impl;
 
 import org.junit.Test;
 import org.onlab.onos.net.GreetService;