diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/Dpid.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/Dpid.java
new file mode 100644
index 0000000..5544354
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/Dpid.java
@@ -0,0 +1,74 @@
+package net.onrc.onos.of.ctl.util;
+
+import org.projectfloodlight.openflow.util.HexString;
+
+/**
+ * The class representing a network switch DPID.
+ * This class is immutable.
+ */
+public final class Dpid {
+    private static final long UNKNOWN = 0;
+    private final long value;
+
+    /**
+     * Default constructor.
+     */
+    public Dpid() {
+        this.value = Dpid.UNKNOWN;
+    }
+
+    /**
+     * Constructor from a long value.
+     *
+     * @param value the value to use.
+     */
+    public Dpid(long value) {
+        this.value = value;
+    }
+
+    /**
+     * Constructor from a string.
+     *
+     * @param value the value to use.
+     */
+    public Dpid(String value) {
+        this.value = HexString.toLong(value);
+    }
+
+    /**
+     * Get the value of the DPID.
+     *
+     * @return the value of the DPID.
+     */
+    public long value() {
+        return value;
+    }
+
+    /**
+     * Convert the DPID value to a ':' separated hexadecimal string.
+     *
+     * @return the DPID value as a ':' separated hexadecimal string.
+     */
+    @Override
+    public String toString() {
+        return HexString.toHexString(this.value);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (!(other instanceof Dpid)) {
+            return false;
+        }
+
+        Dpid otherDpid = (Dpid) other;
+
+        return value == otherDpid.value;
+    }
+
+    @Override
+    public int hashCode() {
+        int hash = 17;
+        hash += 31 * hash + (int) (value ^ value >>> 32);
+        return hash;
+    }
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/DummySwitchForTesting.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/DummySwitchForTesting.java
new file mode 100644
index 0000000..a8eabce
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/DummySwitchForTesting.java
@@ -0,0 +1,360 @@
+package net.onrc.onos.of.ctl.util;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.Future;
+
+import org.jboss.netty.channel.Channel;
+import org.projectfloodlight.openflow.protocol.OFActionType;
+import org.projectfloodlight.openflow.protocol.OFCapabilities;
+import org.projectfloodlight.openflow.protocol.OFDescStatsReply;
+import org.projectfloodlight.openflow.protocol.OFFeaturesReply;
+import org.projectfloodlight.openflow.protocol.OFMessage;
+import org.projectfloodlight.openflow.protocol.OFPortDesc;
+import org.projectfloodlight.openflow.protocol.OFPortDescStatsReply;
+import org.projectfloodlight.openflow.protocol.OFPortStatus;
+import org.projectfloodlight.openflow.protocol.OFStatsReply;
+import org.projectfloodlight.openflow.protocol.OFStatsRequest;
+import org.projectfloodlight.openflow.protocol.OFVersion;
+import org.projectfloodlight.openflow.types.DatapathId;
+import org.projectfloodlight.openflow.types.U64;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import net.onrc.onos.of.ctl.IOFSwitch;
+import net.onrc.onos.of.ctl.Role;
+import net.onrc.onos.of.ctl.debugcounter.IDebugCounterService;
+import net.onrc.onos.of.ctl.debugcounter.IDebugCounterService.CounterException;
+
+public class DummySwitchForTesting implements IOFSwitch {
+
+    protected static final Logger log = LoggerFactory.getLogger(DummySwitchForTesting.class);
+
+    private Channel channel;
+    private boolean connected = false;
+    private OFVersion ofv = OFVersion.OF_10;
+
+    private Collection<OFPortDesc> ports;
+
+    private DatapathId datapathId;
+
+    private Set<OFCapabilities> capabilities;
+
+    private int buffers;
+
+    private byte tables;
+
+    private String stringId;
+
+    private Role role;
+
+    @Override
+    public void disconnectSwitch() {
+        this.channel.close();
+    }
+
+    @Override
+    public void write(OFMessage m) throws IOException {
+        this.channel.write(m);
+
+    }
+
+    @Override
+    public void write(List<OFMessage> msglist) throws IOException {
+        for (OFMessage m : msglist) {
+            this.channel.write(m);
+        }
+
+    }
+
+    @Override
+    public Date getConnectedSince() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public int getNextTransactionId() {
+        return 0;
+    }
+
+    @Override
+    public boolean isConnected() {
+        return this.connected;
+    }
+
+    @Override
+    public void setConnected(boolean connected) {
+        this.connected  = connected;
+
+    }
+
+    @Override
+    public void flush() {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public void setChannel(Channel channel) {
+        this.channel = channel;
+
+    }
+
+    @Override
+    public long getId() {
+        if (this.stringId == null) {
+            throw new RuntimeException("Features reply has not yet been set");
+        }
+        return this.datapathId.getLong();
+    }
+
+    @Override
+    public String getStringId() {
+        // TODO Auto-generated method stub
+        return "DummySwitch";
+    }
+
+    @Override
+    public int getNumBuffers() {
+        // TODO Auto-generated method stub
+        return 0;
+    }
+
+    @Override
+    public Set<OFCapabilities> getCapabilities() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public byte getNumTables() {
+        // TODO Auto-generated method stub
+        return 0;
+    }
+
+    @Override
+    public OFDescStatsReply getSwitchDescription() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void cancelFeaturesReply(int transactionId) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public Set<OFActionType> getActions() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void setOFVersion(OFVersion version) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public OFVersion getOFVersion() {
+        return this.ofv;
+    }
+
+    @Override
+    public Collection<OFPortDesc> getEnabledPorts() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public Collection<Integer> getEnabledPortNumbers() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public OFPortDesc getPort(int portNumber) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public OFPortDesc getPort(String portName) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public OrderedCollection<PortChangeEvent> processOFPortStatus(
+            OFPortStatus ps) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public Collection<OFPortDesc> getPorts() {
+        return ports;
+    }
+
+    @Override
+    public boolean portEnabled(int portName) {
+        // TODO Auto-generated method stub
+        return false;
+    }
+
+    @Override
+    public OrderedCollection<PortChangeEvent> setPorts(
+            Collection<OFPortDesc> p) {
+        this.ports = p;
+        return null;
+    }
+
+    @Override
+    public Map<Object, Object> getAttributes() {
+        return null;
+    }
+
+    @Override
+    public boolean hasAttribute(String name) {
+        // TODO Auto-generated method stub
+        return false;
+    }
+
+    @Override
+    public Object getAttribute(String name) {
+        return Boolean.FALSE;
+    }
+
+    @Override
+    public void setAttribute(String name, Object value) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public Object removeAttribute(String name) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void deliverStatisticsReply(OFMessage reply) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public void cancelStatisticsReply(int transactionId) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public void cancelAllStatisticsReplies() {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public Future<List<OFStatsReply>> getStatistics(OFStatsRequest<?> request)
+            throws IOException {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void clearAllFlowMods() {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public Role getRole() {
+        return this.role;
+    }
+
+    @Override
+    public void setRole(Role role) {
+        this.role = role;
+    }
+
+    @Override
+    public U64 getNextGenerationId() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void setDebugCounterService(IDebugCounterService debugCounter)
+            throws CounterException {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public void startDriverHandshake() throws IOException {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public boolean isDriverHandshakeComplete() {
+        return true;
+    }
+
+    @Override
+    public void processDriverHandshakeMessage(OFMessage m) {
+
+    }
+
+    @Override
+    public void setTableFull(boolean isFull) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public void setFeaturesReply(OFFeaturesReply featuresReply) {
+        if (featuresReply == null) {
+            log.error("Error setting featuresReply for switch: {}", getStringId());
+            return;
+        }
+        this.datapathId = featuresReply.getDatapathId();
+        this.capabilities = featuresReply.getCapabilities();
+        this.buffers = (int) featuresReply.getNBuffers();
+        this.tables = (byte) featuresReply.getNTables();
+        this.stringId = this.datapathId.toString();
+
+    }
+
+    @Override
+    public void setPortDescReply(OFPortDescStatsReply portDescReply) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public void handleMessage(OFMessage m) {
+        log.info("Got packet {} but I am dumb so I don't know what to do.", m);
+    }
+
+    @Override
+    public boolean portEnabled(String portName) {
+        // TODO Auto-generated method stub
+        return false;
+    }
+
+    @Override
+    public OrderedCollection<PortChangeEvent> comparePorts(
+            Collection<OFPortDesc> p) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/EnumBitmaps.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/EnumBitmaps.java
new file mode 100644
index 0000000..fe6ccc0
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/EnumBitmaps.java
@@ -0,0 +1,149 @@
+package net.onrc.onos.of.ctl.util;
+
+import java.util.EnumSet;
+import java.util.Set;
+
+/**
+ * A utility class to convert between integer based bitmaps for (OpenFlow)
+ * flags and Enum and EnumSet based representations.
+ *
+ * The enum used to represent individual flags needs to implement the
+ * BitmapableEnum interface.
+ *
+ * Example:
+ * {@code
+ *   int bitmap = 0x11; // OFPPC_PORT_DOWN | OFPPC_NO_STP
+ *   EnumSet<OFPortConfig> s = toEnumSet(OFPortConfig.class, bitmap);
+ *   // s will contain OFPPC_PORT_DOWN and OFPPC_NO_STP
+ * }
+ *
+ * {@code
+ *    EnumSet<OFPortConfig> s = EnumSet.of(OFPPC_NO_STP, OFPPC_PORT_DOWN);
+ *    int bitmap = toBitmap(s); // returns 0x11
+ * }
+ *
+ */
+public final class EnumBitmaps {
+
+
+    private EnumBitmaps() { }
+
+    /**
+     * Enums used to represent individual flags needs to implement this
+     * interface.
+     */
+    public interface BitmapableEnum {
+        /** Return the value in the bitmap that the enum constant represents.
+         * The returned value must have only a single bit set. E.g.,1 << 3
+         */
+        int getValue();
+    }
+
+
+    /**
+     * Convert an integer bitmap to an EnumSet.
+     *
+     * See class description for example
+     * @param type The Enum class to use. Must implement BitmapableEnum
+     * @param bitmap The integer bitmap
+     * @return A newly allocated EnumSet representing the bits set in the
+     * bitmap
+     * @throws NullPointerException if type is null
+     * @throws IllegalArgumentException if any enum constant from type has
+     * more than one bit set.
+     * @throws IllegalArgumentException if the bitmap has any bits set not
+     * represented by an enum constant.
+     */
+    public static <E extends Enum<E> & BitmapableEnum>
+            EnumSet<E> toEnumSet(Class<E> type, int bitmap) {
+        if (type == null) {
+            throw new NullPointerException("Given enum type must not be null");
+        }
+        EnumSet<E> s = EnumSet.noneOf(type);
+        // allSetBitmap will eventually have all valid bits for the given
+        // type set.
+        int allSetBitmap = 0;
+        for (E element: type.getEnumConstants()) {
+            if (Integer.bitCount(element.getValue()) != 1) {
+                String msg = String.format("The %s (%x) constant of the " +
+                        "enum %s is supposed to represent a bitmap entry but " +
+                        "has more than one bit set.",
+                        element.toString(), element.getValue(), type.getName());
+                throw new IllegalArgumentException(msg);
+            }
+            allSetBitmap |= element.getValue();
+            if ((bitmap & element.getValue()) != 0) {
+                s.add(element);
+            }
+        }
+        if (((~allSetBitmap) & bitmap) != 0) {
+            // check if only valid flags are set in the given bitmap
+            String msg = String.format("The bitmap %x for enum %s has " +
+                    "bits set that are presented by any enum constant",
+                    bitmap, type.getName());
+            throw new IllegalArgumentException(msg);
+        }
+        return s;
+    }
+
+    /**
+     * Return the bitmap mask with all possible bits set. E.g., If a bitmap
+     * has the individual flags 0x1, 0x2, and 0x8 (note the missing 0x4) then
+     * the mask will be 0xb (1011 binary)
+     *
+     * @param type The Enum class to use. Must implement BitmapableEnum
+     * @throws NullPointerException if type is null
+     * @throws IllegalArgumentException if any enum constant from type has
+     * more than one bit set
+     * @return an integer with all possible bits for the given bitmap enum
+     * type set.
+     */
+    public static <E extends Enum<E> & BitmapableEnum>
+            int getMask(Class<E> type) {
+        if (type == null) {
+            throw new NullPointerException("Given enum type must not be null");
+        }
+        // allSetBitmap will eventually have all valid bits for the given
+        // type set.
+        int allSetBitmap = 0;
+        for (E element: type.getEnumConstants()) {
+            if (Integer.bitCount(element.getValue()) != 1) {
+                String msg = String.format("The %s (%x) constant of the " +
+                        "enum %s is supposed to represent a bitmap entry but " +
+                        "has more than one bit set.",
+                        element.toString(), element.getValue(), type.getName());
+                throw new IllegalArgumentException(msg);
+            }
+            allSetBitmap |= element.getValue();
+        }
+        return allSetBitmap;
+    }
+
+    /**
+     * Convert the given EnumSet to the integer bitmap representation.
+     * @param set The EnumSet to convert. The enum must implement
+     * BitmapableEnum
+     * @return the integer bitmap
+     * @throws IllegalArgumentException if an enum constant from the set (!) has
+     * more than one bit set
+     * @throws NullPointerException if the set is null
+     */
+    public static <E extends Enum<E> & BitmapableEnum>
+            int toBitmap(Set<E> set) {
+        if (set == null) {
+            throw new NullPointerException("Given set must not be null");
+        }
+        int bitmap = 0;
+        for (E element: set) {
+            if (Integer.bitCount(element.getValue()) != 1) {
+                String msg = String.format("The %s (%x) constant in the set " +
+                        "is supposed to represent a bitmap entry but " +
+                        "has more than one bit set.",
+                        element.toString(), element.getValue());
+                throw new IllegalArgumentException(msg);
+            }
+            bitmap |= element.getValue();
+        }
+        return bitmap;
+    }
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/FilterIterator.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/FilterIterator.java
new file mode 100644
index 0000000..fdde82c
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/FilterIterator.java
@@ -0,0 +1,85 @@
+/**
+ *    Copyright 2012, Big Switch Networks, Inc.
+ *    Originally created by David Erickson, Stanford University
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *    not use this file except in compliance with the License. You may obtain
+ *    a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ *    License for the specific language governing permissions and limitations
+ *    under the License.
+ **/
+
+package net.onrc.onos.of.ctl.util;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * An iterator that will filter values from an iterator and return only
+ * those values that match the predicate.
+ */
+public abstract class FilterIterator<T> implements Iterator<T> {
+    protected Iterator<T> subIterator;
+    protected T next;
+
+    /**
+     * Construct a filter iterator from the given sub iterator.
+     *
+     * @param subIterator the sub iterator over which we'll filter
+     */
+    public FilterIterator(Iterator<T> subIterator) {
+        super();
+        this.subIterator = subIterator;
+    }
+
+    /**
+     * Check whether the given value should be returned by the
+     * filter.
+     *
+     * @param value the value to check
+     * @return true if the value should be included
+     */
+    protected abstract boolean matches(T value);
+
+    // ***********
+    // Iterator<T>
+    // ***********
+
+    @Override
+    public boolean hasNext() {
+        if (next != null) {
+            return true;
+        }
+
+        while (subIterator.hasNext()) {
+            next = subIterator.next();
+            if (matches(next)) {
+                return true;
+            }
+        }
+        next = null;
+        return false;
+    }
+
+    @Override
+    public T next() {
+        if (hasNext()) {
+            T cur = next;
+            next = null;
+            return cur;
+        }
+        throw new NoSuchElementException();
+    }
+
+    @Override
+    public void remove() {
+        throw new UnsupportedOperationException();
+    }
+
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/InstanceId.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/InstanceId.java
new file mode 100644
index 0000000..861dec6
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/InstanceId.java
@@ -0,0 +1,47 @@
+package net.onrc.onos.of.ctl.util;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * The class representing an ONOS Instance ID.
+ *
+ * This class is immutable.
+ */
+public final class InstanceId {
+    private final String id;
+
+    /**
+     * Constructor from a string value.
+     *
+     * @param id the value to use.
+     */
+    public InstanceId(String id) {
+        this.id = checkNotNull(id);
+        checkArgument(!id.isEmpty(), "Empty ONOS Instance ID");
+    }
+
+    @Override
+    public int hashCode() {
+        return id.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) {
+            return true;
+        }
+
+        if (!(obj instanceof InstanceId)) {
+            return false;
+        }
+
+        InstanceId that = (InstanceId) obj;
+        return this.id.equals(that.id);
+    }
+
+    @Override
+    public String toString() {
+        return id;
+    }
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/IterableIterator.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/IterableIterator.java
new file mode 100644
index 0000000..79f3c9d
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/IterableIterator.java
@@ -0,0 +1,68 @@
+/**
+ *    Copyright 2012 Big Switch Networks, Inc.
+ *    Originally created by David Erickson, Stanford University
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *    not use this file except in compliance with the License. You may obtain
+ *    a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ *    License for the specific language governing permissions and limitations
+ *    under the License.
+ **/
+
+package net.onrc.onos.of.ctl.util;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * Iterator over all values in an iterator of iterators.
+ *
+ * @param <T> the type of elements returned by this iterator
+ */
+public class IterableIterator<T> implements Iterator<T> {
+    Iterator<? extends Iterable<T>> subIterator;
+    Iterator<T> current = null;
+
+    public IterableIterator(Iterator<? extends Iterable<T>> subIterator) {
+        super();
+        this.subIterator = subIterator;
+    }
+
+    @Override
+    public boolean hasNext() {
+        if (current == null) {
+            if (subIterator.hasNext()) {
+                current = subIterator.next().iterator();
+            } else {
+                return false;
+            }
+        }
+        while (!current.hasNext() && subIterator.hasNext()) {
+            current = subIterator.next().iterator();
+        }
+
+        return current.hasNext();
+    }
+
+    @Override
+    public T next() {
+        if (hasNext()) {
+            return current.next();
+        }
+        throw new NoSuchElementException();
+    }
+
+    @Override
+    public void remove() {
+        if (hasNext()) {
+            current.remove();
+        }
+        throw new NoSuchElementException();
+    }
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/LRUHashMap.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/LRUHashMap.java
new file mode 100644
index 0000000..17f9354
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/LRUHashMap.java
@@ -0,0 +1,38 @@
+/**
+ *    Copyright 2011, Big Switch Networks, Inc.
+ *    Originally created by David Erickson, Stanford University
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *    not use this file except in compliance with the License. You may obtain
+ *    a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ *    License for the specific language governing permissions and limitations
+ *    under the License.
+ **/
+
+package net.onrc.onos.of.ctl.util;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public class LRUHashMap<K, V> extends LinkedHashMap<K, V> {
+
+    private static final long serialVersionUID = 1L;
+
+    private final int capacity;
+
+    public LRUHashMap(int capacity) {
+        super(capacity + 1, 0.75f, true);
+        this.capacity = capacity;
+    }
+
+    protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
+        return size() > capacity;
+    }
+
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/LinkedHashSetWrapper.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/LinkedHashSetWrapper.java
new file mode 100644
index 0000000..629e536
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/LinkedHashSetWrapper.java
@@ -0,0 +1,32 @@
+package net.onrc.onos.of.ctl.util;
+
+import java.util.Collection;
+import java.util.LinkedHashSet;
+
+import com.google.common.collect.ForwardingCollection;
+
+/**
+ * A simple wrapper / forwarder that forwards all calls to a LinkedHashSet.
+ * This wrappers sole reason for existence is to implement the
+ * OrderedCollection marker interface.
+ *
+ */
+public class LinkedHashSetWrapper<E>
+        extends ForwardingCollection<E> implements OrderedCollection<E> {
+    private final Collection<E> delegate;
+
+    public LinkedHashSetWrapper() {
+        super();
+        this.delegate = new LinkedHashSet<E>();
+    }
+
+    public LinkedHashSetWrapper(Collection<? extends E> c) {
+        super();
+        this.delegate = new LinkedHashSet<E>(c);
+    }
+
+    @Override
+    protected Collection<E> delegate() {
+        return this.delegate;
+    }
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/MultiIterator.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/MultiIterator.java
new file mode 100644
index 0000000..693a8bf
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/MultiIterator.java
@@ -0,0 +1,68 @@
+/**
+ *    Copyright 2012 Big Switch Networks, Inc.
+ *    Originally created by David Erickson, Stanford University
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *    not use this file except in compliance with the License. You may obtain
+ *    a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ *    License for the specific language governing permissions and limitations
+ *    under the License.
+ **/
+
+package net.onrc.onos.of.ctl.util;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * Iterator over all values in an iterator of iterators.
+ *
+ * @param <T> the type of elements returned by this iterator
+ */
+public class MultiIterator<T> implements Iterator<T> {
+    Iterator<Iterator<T>> subIterator;
+    Iterator<T> current = null;
+
+    public MultiIterator(Iterator<Iterator<T>> subIterator) {
+        super();
+        this.subIterator = subIterator;
+    }
+
+    @Override
+    public boolean hasNext() {
+        if (current == null) {
+            if (subIterator.hasNext()) {
+                current = subIterator.next();
+            } else {
+                return false;
+            }
+        }
+        while (!current.hasNext() && subIterator.hasNext()) {
+            current = subIterator.next();
+        }
+
+        return current.hasNext();
+    }
+
+    @Override
+    public T next() {
+        if (hasNext()) {
+            return current.next();
+        }
+        throw new NoSuchElementException();
+    }
+
+    @Override
+    public void remove() {
+        if (hasNext()) {
+            current.remove();
+        }
+        throw new NoSuchElementException();
+    }
+}
diff --git a/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/OrderedCollection.java b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/OrderedCollection.java
new file mode 100644
index 0000000..f032212
--- /dev/null
+++ b/of-save/ctl/src/main/java/net/onrc/onos/of/ctl/util/OrderedCollection.java
@@ -0,0 +1,14 @@
+package net.onrc.onos.of.ctl.util;
+
+import java.util.Collection;
+
+/**
+ * A marker interface indicating that this Collection defines a particular
+ * iteration order. The details about the iteration order are specified by
+ * the concrete implementation.
+ *
+ * @param <E>
+ */
+public interface OrderedCollection<E> extends Collection<E> {
+
+}