diff --git a/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalysisCommand.java b/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalysisCommand.java
new file mode 100644
index 0000000..2c61949
--- /dev/null
+++ b/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalysisCommand.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.flowanalyzer;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onosproject.cli.AbstractShellCommand;
+
+/**
+ * Analyzes flows for cycles and black holes.
+ */
+@Command(scope = "onos", name = "flow-analysis",
+         description = "Analyzes flows for cycles and black holes")
+public class FlowAnalysisCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        FlowAnalyzer service = get(FlowAnalyzer.class);
+        print(service.analyze());
+    }
+}
diff --git a/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalyzer.java b/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalyzer.java
index 5d99d74..6aaaaee 100644
--- a/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalyzer.java
+++ b/apps/flowanalyzer/src/main/java/org/onosproject/flowanalyzer/FlowAnalyzer.java
@@ -21,12 +21,31 @@
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.FlowEntry;
 import org.onosproject.net.flow.FlowRuleService;
-import org.onosproject.net.host.HostService;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.HostId;
+import org.onosproject.net.flow.criteria.Criteria;
+import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.criteria.PortCriterion;
+import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flow.instructions.Instructions;
+import org.onosproject.net.topology.TopologyService;
+import org.onosproject.net.topology.TopologyGraph;
 import org.onosproject.net.link.LinkService;
+import org.onosproject.net.Link;
+import org.onosproject.net.topology.TopologyVertex;
 import org.osgi.service.component.ComponentContext;
 import org.slf4j.Logger;
 
+import java.util.HashSet;
+import java.util.List;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**
@@ -42,11 +61,10 @@
     protected FlowRuleService flowRuleService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected LinkService linkService;
+    protected TopologyService topologyService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected HostService hostService;
-
+    protected LinkService linkService;
 
     @Activate
     public void activate(ComponentContext context) {
@@ -58,12 +76,193 @@
         log.info("Stopped");
     }
 
+    TopologyGraph graph;
+    Map<FlowEntry, String> label = new HashMap<>();
+    Set<FlowEntry> ignoredFlows = new HashSet<>();
 
     /**
-     * ...
+     * Analyzes and prints out a report on the status of every flow entry inside
+     * the network. The possible states are: Cleared (implying that the entry leads to
+     * a host), Cycle (implying that it is part of cycle), and Black Hole (implying
+     * that the entry does not lead to a single host).
      */
-    public void analyze() {
-        // TODO: implement this
+    public String analyze() {
+        graph = topologyService.getGraph(topologyService.currentTopology());
+        for (TopologyVertex v: graph.getVertexes()) {
+            DeviceId srcDevice = v.deviceId();
+            Iterable<FlowEntry> flowTable = flowRuleService.getFlowEntries(srcDevice);
+            for (FlowEntry flow: flowTable) {
+                dfs(flow);
+            }
+        }
+
+        //analyze the cycles to look for "critical flows" that can be removed
+        //to break the cycle
+        Set<FlowEntry> critpts = new HashSet<>();
+        for (FlowEntry flow: label.keySet()) {
+            if ("Cycle".equals(label.get(flow))) {
+                Map<FlowEntry, String> labelSaved = label;
+                label = new HashMap<FlowEntry, String>();
+                ignoredFlows.add(flow);
+                for (TopologyVertex v: graph.getVertexes()) {
+                    DeviceId srcDevice = v.deviceId();
+                    Iterable<FlowEntry> flowTable = flowRuleService.getFlowEntries(srcDevice);
+                    for (FlowEntry flow1: flowTable) {
+                        dfs(flow1);
+                    }
+                }
+
+                boolean replacable = true;
+                for (FlowEntry flow2: label.keySet()) {
+                    if ("Cleared".equals(labelSaved.get(flow2)) && !("Cleared".equals(label.get(flow2)))) {
+                        replacable = false;
+                    }
+                }
+                if (replacable) {
+                    critpts.add(flow);
+                }
+                label = labelSaved;
+            }
+        }
+
+        for (FlowEntry flow: critpts) {
+            label.put(flow, "Cycle Critical Point");
+        }
+
+        String s = "\n";
+        for (FlowEntry flow: label.keySet()) {
+            s += ("Flow Rule: " + flowEntryRepresentation(flow) + "\n");
+            s += ("Analysis: " + label.get(flow) + "!\n\n");
+        }
+        s += ("Analyzed " + label.keySet().size() + " flows.");
+        //log.info(s);
+        return s;
     }
 
+    public Map<FlowEntry, String> calcLabels() {
+        analyze();
+        return label;
+    }
+    public String analysisOutput()   {
+        analyze();
+        String s = "\n";
+        for (FlowEntry flow: label.keySet()) {
+            s += ("Flow Rule: " + flowEntryRepresentation(flow) + "\n");
+            s += ("Analysis: " + label.get(flow) + "!\n\n");
+        }
+        return s;
+    }
+
+    private boolean dfs(FlowEntry flow) {
+        if (ignoredFlows.contains(flow)) {
+            return false;
+        }
+        if ("Cycle".equals(label.get(flow)) ||
+                "Black Hole".equals(label.get(flow)) ||
+                "Cleared".equals(label.get(flow)) ||
+                 "NA".equals(label.get(flow)) ||
+                "Cycle Critical Point".equals(label.get(flow))) {
+
+            // This flow has already been analyzed and there is no need to analyze it further
+            return !"Black Hole".equals(label.get(flow));
+        }
+
+        if ("Visiting".equals(label.get(flow))) {
+            //you've detected a cycle because you reached the same entry again during your dfs
+            //let it continue so you can label the whole cycle
+            label.put(flow, "Cycle");
+        } else {
+            //otherwise, mark off the current flow entry as currently being visited
+            label.put(flow, "Visiting");
+        }
+
+        boolean pointsToLiveEntry = false;
+
+        List<Instruction> instructions = flow.treatment().allInstructions();
+        for (Instruction i: instructions) {
+            if (i instanceof Instructions.OutputInstruction) {
+                pointsToLiveEntry |= analyzeInstruction(i, flow);
+            }
+            if ("NA".equals(label.get(flow))) {
+                return pointsToLiveEntry;
+            }
+        }
+
+        if (!pointsToLiveEntry) {
+            //this entry does not point to any "live" entries thus must be a black hole
+            label.put(flow, "Black Hole");
+        } else if ("Visiting".equals(label.get(flow))) {
+            //the flow is not in a cycle or in a black hole
+            label.put(flow, "Cleared");
+        }
+        return pointsToLiveEntry;
+    }
+
+    private boolean analyzeInstruction(Instruction i, FlowEntry flow) {
+        boolean pointsToLiveEntry = false;
+        Instructions.OutputInstruction output = (Instructions.OutputInstruction) i;
+        PortNumber port = output.port();
+        PortNumber outPort = null;
+
+        DeviceId egress = null;
+        boolean hasHost = false;
+
+        ConnectPoint portPt = new ConnectPoint(flow.deviceId(), port);
+        for (Link l: linkService.getEgressLinks(portPt)) {
+            if (l.dst().elementId() instanceof DeviceId) {
+                egress = l.dst().deviceId();
+                outPort = l.dst().port();
+            } else if (l.dst().elementId() instanceof HostId) {
+                //the port leads to a host: therefore it is not a dead link
+                pointsToLiveEntry = true;
+                hasHost = true;
+            }
+        }
+        if (!topologyService.isInfrastructure(topologyService.currentTopology(), portPt) && egress == null) {
+            pointsToLiveEntry = true;
+            hasHost = true;
+        }
+        if (hasHost) {
+            return pointsToLiveEntry;
+        }
+        if (egress == null) {
+            //the port that the flow instructions tells you to send the packet
+            //to doesn't exist or is a controller port
+            label.put(flow, "NA");
+            return pointsToLiveEntry;
+        }
+
+        Iterable<FlowEntry> dstFlowTable = flowRuleService.getFlowEntries(egress);
+
+        Set<Criterion> flowCriteria = flow.selector().criteria();
+
+        //filter the criteria in order to remove port dependency
+        Set<Criterion> filteredCriteria = new HashSet<>();
+        for (Criterion criterion : flowCriteria) {
+            if (!(criterion instanceof PortCriterion)) {
+                filteredCriteria.add(criterion);
+            }
+        }
+
+        //ensure that the in port is equal to the port that it is coming in from
+        filteredCriteria.add(Criteria.matchInPort(outPort));
+
+        for (FlowEntry entry: dstFlowTable) {
+            if (ignoredFlows.contains(entry)) {
+                continue;
+            }
+            if (filteredCriteria.containsAll(entry.selector().criteria())) {
+                dfs(entry);
+
+                if (!"Black Hole".equals(label.get(entry))) {
+                    //this entry is "live" i.e not a black hole
+                    pointsToLiveEntry = true;
+                }
+            }
+        }
+        return pointsToLiveEntry;
+    }
+    public String flowEntryRepresentation(FlowEntry flow) {
+        return "Device: " + flow.deviceId() + ", " + flow.selector().criteria() + ", " + flow.treatment().immediate();
+    }
 }
diff --git a/apps/flowanalyzer/src/main/resources/OSGI-INF/blueprint/shell-config.xml b/apps/flowanalyzer/src/main/resources/OSGI-INF/blueprint/shell-config.xml
new file mode 100644
index 0000000..93cb27e
--- /dev/null
+++ b/apps/flowanalyzer/src/main/resources/OSGI-INF/blueprint/shell-config.xml
@@ -0,0 +1,23 @@
+<!--
+  ~ Copyright 2015 Open Networking Laboratory
+  ~
+  ~ 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.
+  -->
+<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0">
+    <command-bundle xmlns="http://karaf.apache.org/xmlns/shell/v1.1.0">
+        <command>
+            <action class="org.onosproject.flowanalyzer.FlowAnalysisCommand"/>
+        </command>
+
+    </command-bundle>
+</blueprint>