diff --git a/utils/misc/src/test/java/org/onlab/graph/BellmanFordGraphSearchTest.java b/utils/misc/src/test/java/org/onlab/graph/BellmanFordGraphSearchTest.java
index 4ee9006..96985b5 100644
--- a/utils/misc/src/test/java/org/onlab/graph/BellmanFordGraphSearchTest.java
+++ b/utils/misc/src/test/java/org/onlab/graph/BellmanFordGraphSearchTest.java
@@ -31,17 +31,17 @@
 
     @Test
     public void searchGraphWithNegativeCycles() {
-        Set<TestVertex> vertexes = new HashSet<>(vertices());
+        Set<TestVertex> vertexes = new HashSet<>(vertexes());
         vertexes.add(Z);
 
         Set<TestEdge> edges = new HashSet<>(edges());
         edges.add(new TestEdge(G, Z, 1.0));
         edges.add(new TestEdge(Z, G, -2.0));
 
-        g = new AdjacencyListsGraph<>(vertexes, edges);
+        graph = new AdjacencyListsGraph<>(vertexes, edges);
 
         GraphPathSearch<TestVertex, TestEdge> search = graphSearch();
-        Set<Path<TestVertex, TestEdge>> paths = search.search(g, A, H, weight).paths();
+        Set<Path<TestVertex, TestEdge>> paths = search.search(graph, A, H, weight).paths();
         assertEquals("incorrect paths count", 1, paths.size());
 
         Path p = paths.iterator().next();
@@ -50,10 +50,10 @@
         assertEquals("incorrect path length", 5, p.edges().size());
         assertEquals("incorrect path cost", 5.0, p.cost(), 0.1);
 
-        paths = search.search(g, A, G, weight).paths();
+        paths = search.search(graph, A, G, weight).paths();
         assertEquals("incorrect paths count", 0, paths.size());
 
-        paths = search.search(g, A, null, weight).paths();
+        paths = search.search(graph, A, null, weight).paths();
         printPaths(paths);
         assertEquals("incorrect paths count", 6, paths.size());
     }
diff --git a/utils/misc/src/test/java/org/onlab/graph/BreadthFirstSearchTest.java b/utils/misc/src/test/java/org/onlab/graph/BreadthFirstSearchTest.java
index f9c752d..d99e485 100644
--- a/utils/misc/src/test/java/org/onlab/graph/BreadthFirstSearchTest.java
+++ b/utils/misc/src/test/java/org/onlab/graph/BreadthFirstSearchTest.java
@@ -29,10 +29,10 @@
 
     // Executes the default test
     protected void executeDefaultTest(int pathCount, int pathLength, double pathCost) {
-        g = new AdjacencyListsGraph<>(vertices(), edges());
+        graph = new AdjacencyListsGraph<>(vertexes(), edges());
 
         GraphPathSearch<TestVertex, TestEdge> search = graphSearch();
-        Set<Path<TestVertex, TestEdge>> paths = search.search(g, A, H, weight).paths();
+        Set<Path<TestVertex, TestEdge>> paths = search.search(graph, A, H, weight).paths();
         assertEquals("incorrect paths count", 1, paths.size());
 
         Path p = paths.iterator().next();
@@ -41,7 +41,7 @@
         assertEquals("incorrect path length", pathLength, p.edges().size());
         assertEquals("incorrect path cost", pathCost, p.cost(), 0.1);
 
-        paths = search.search(g, A, null, weight).paths();
+        paths = search.search(graph, A, null, weight).paths();
         printPaths(paths);
         assertEquals("incorrect paths count", pathCount, paths.size());
     }
diff --git a/utils/misc/src/test/java/org/onlab/graph/DepthFirstSearchTest.java b/utils/misc/src/test/java/org/onlab/graph/DepthFirstSearchTest.java
index 8881e84..944919b 100644
--- a/utils/misc/src/test/java/org/onlab/graph/DepthFirstSearchTest.java
+++ b/utils/misc/src/test/java/org/onlab/graph/DepthFirstSearchTest.java
@@ -33,11 +33,11 @@
 
     protected void executeDefaultTest(int minLength, int maxLength,
                                       double minCost, double maxCost) {
-        g = new AdjacencyListsGraph<>(vertices(), edges());
+        graph = new AdjacencyListsGraph<>(vertexes(), edges());
         DepthFirstSearch<TestVertex, TestEdge> search = graphSearch();
 
         DepthFirstSearch<TestVertex, TestEdge>.SpanningTreeResult result =
-                search.search(g, A, H, weight);
+                search.search(graph, A, H, weight);
         Set<Path<TestVertex, TestEdge>> paths = result.paths();
         assertEquals("incorrect path count", 1, paths.size());
 
@@ -57,12 +57,12 @@
     }
 
     public void executeBroadSearch() {
-        g = new AdjacencyListsGraph<>(vertices(), edges());
+        graph = new AdjacencyListsGraph<>(vertexes(), edges());
         DepthFirstSearch<TestVertex, TestEdge> search = graphSearch();
 
         // Perform narrow path search to a specific destination.
         DepthFirstSearch<TestVertex, TestEdge>.SpanningTreeResult result =
-                search.search(g, A, null, weight);
+                search.search(graph, A, null, weight);
         assertEquals("incorrect paths count", 7, result.paths().size());
 
         int[] types = new int[]{0, 0, 0, 0};
diff --git a/utils/misc/src/test/java/org/onlab/graph/DijkstraGraphSearchTest.java b/utils/misc/src/test/java/org/onlab/graph/DijkstraGraphSearchTest.java
index 1731440..840eddd 100644
--- a/utils/misc/src/test/java/org/onlab/graph/DijkstraGraphSearchTest.java
+++ b/utils/misc/src/test/java/org/onlab/graph/DijkstraGraphSearchTest.java
@@ -32,22 +32,22 @@
 
     @Test
     public void noPath() {
-        g = new AdjacencyListsGraph<>(of(A, B, C, D),
-                                      of(new TestEdge(A, B, 1),
-                                         new TestEdge(B, A, 1),
-                                         new TestEdge(C, D, 1),
-                                         new TestEdge(D, C, 1)));
+        graph = new AdjacencyListsGraph<>(of(A, B, C, D),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(B, A, 1),
+                                             new TestEdge(C, D, 1),
+                                             new TestEdge(D, C, 1)));
         GraphPathSearch<TestVertex, TestEdge> gs = graphSearch();
-        Set<Path<TestVertex, TestEdge>> paths = gs.search(g, A, B, weight).paths();
+        Set<Path<TestVertex, TestEdge>> paths = gs.search(graph, A, B, weight).paths();
         printPaths(paths);
         assertEquals("incorrect paths count", 1, paths.size());
         assertEquals("incorrect path cost", 1.0, paths.iterator().next().cost(), 0.1);
 
-        paths = gs.search(g, A, D, weight).paths();
+        paths = gs.search(graph, A, D, weight).paths();
         printPaths(paths);
         assertEquals("incorrect paths count", 0, paths.size());
 
-        paths = gs.search(g, A, null, weight).paths();
+        paths = gs.search(graph, A, null, weight).paths();
         printPaths(paths);
         assertEquals("incorrect paths count", 1, paths.size());
         assertEquals("incorrect path cost", 1.0, paths.iterator().next().cost(), 0.1);
@@ -55,40 +55,40 @@
 
     @Test
     public void simpleMultiplePath() {
-        g = new AdjacencyListsGraph<>(of(A, B, C, D),
-                                      of(new TestEdge(A, B, 1),
-                                         new TestEdge(A, C, 1),
-                                         new TestEdge(B, D, 1),
-                                         new TestEdge(C, D, 1)));
-        executeSearch(graphSearch(), g, A, D, weight, 2, 2.0);
+        graph = new AdjacencyListsGraph<>(of(A, B, C, D),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(A, C, 1),
+                                             new TestEdge(B, D, 1),
+                                             new TestEdge(C, D, 1)));
+        executeSearch(graphSearch(), graph, A, D, weight, 2, 2.0);
     }
 
     @Test
     public void denseMultiplePath() {
-        g = new AdjacencyListsGraph<>(of(A, B, C, D, E, F, G),
-                                      of(new TestEdge(A, B, 1),
-                                         new TestEdge(A, C, 1),
-                                         new TestEdge(B, D, 1),
-                                         new TestEdge(C, D, 1),
-                                         new TestEdge(D, E, 1),
-                                         new TestEdge(D, F, 1),
-                                         new TestEdge(E, G, 1),
-                                         new TestEdge(F, G, 1),
-                                         new TestEdge(A, G, 4)));
-        executeSearch(graphSearch(), g, A, G, weight, 5, 4.0);
+        graph = new AdjacencyListsGraph<>(of(A, B, C, D, E, F, G),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(A, C, 1),
+                                             new TestEdge(B, D, 1),
+                                             new TestEdge(C, D, 1),
+                                             new TestEdge(D, E, 1),
+                                             new TestEdge(D, F, 1),
+                                             new TestEdge(E, G, 1),
+                                             new TestEdge(F, G, 1),
+                                             new TestEdge(A, G, 4)));
+        executeSearch(graphSearch(), graph, A, G, weight, 5, 4.0);
     }
 
     @Test
     public void dualEdgeMultiplePath() {
-        g = new AdjacencyListsGraph<>(of(A, B, C, D, E, F, G, H),
-                                      of(new TestEdge(A, B, 1), new TestEdge(A, C, 3),
-                                         new TestEdge(B, D, 2), new TestEdge(B, C, 1),
-                                         new TestEdge(B, E, 4), new TestEdge(C, E, 1),
-                                         new TestEdge(D, H, 5), new TestEdge(D, E, 1),
-                                         new TestEdge(E, F, 1), new TestEdge(F, D, 1),
-                                         new TestEdge(F, G, 1), new TestEdge(F, H, 1),
-                                         new TestEdge(A, E, 3), new TestEdge(B, D, 1)));
-        executeSearch(graphSearch(), g, A, E, weight, 3, 3.0);
+        graph = new AdjacencyListsGraph<>(of(A, B, C, D, E, F, G, H),
+                                          of(new TestEdge(A, B, 1), new TestEdge(A, C, 3),
+                                             new TestEdge(B, D, 2), new TestEdge(B, C, 1),
+                                             new TestEdge(B, E, 4), new TestEdge(C, E, 1),
+                                             new TestEdge(D, H, 5), new TestEdge(D, E, 1),
+                                             new TestEdge(E, F, 1), new TestEdge(F, D, 1),
+                                             new TestEdge(F, G, 1), new TestEdge(F, H, 1),
+                                             new TestEdge(A, E, 3), new TestEdge(B, D, 1)));
+        executeSearch(graphSearch(), graph, A, E, weight, 3, 3.0);
     }
 
 }
diff --git a/utils/misc/src/test/java/org/onlab/graph/GraphTest.java b/utils/misc/src/test/java/org/onlab/graph/GraphTest.java
index 44b1137..5c930c4 100644
--- a/utils/misc/src/test/java/org/onlab/graph/GraphTest.java
+++ b/utils/misc/src/test/java/org/onlab/graph/GraphTest.java
@@ -19,7 +19,7 @@
     static final TestVertex H = new TestVertex("H");
     static final TestVertex Z = new TestVertex("Z");
 
-    protected Graph<TestVertex, TestEdge> g;
+    protected Graph<TestVertex, TestEdge> graph;
 
     protected EdgeWeight<TestVertex, TestEdge> weight =
             new EdgeWeight<TestVertex, TestEdge>() {
@@ -35,7 +35,7 @@
         }
     }
 
-    protected Set<TestVertex> vertices() {
+    protected Set<TestVertex> vertexes() {
         return of(A, B, C, D, E, F, G, H);
     }
 
diff --git a/utils/misc/src/test/java/org/onlab/graph/TarjanGraphSearchTest.java b/utils/misc/src/test/java/org/onlab/graph/TarjanGraphSearchTest.java
new file mode 100644
index 0000000..9bf3acf
--- /dev/null
+++ b/utils/misc/src/test/java/org/onlab/graph/TarjanGraphSearchTest.java
@@ -0,0 +1,110 @@
+package org.onlab.graph;
+
+import org.junit.Test;
+
+import static com.google.common.collect.ImmutableSet.of;
+import static org.junit.Assert.assertEquals;
+import static org.onlab.graph.TarjanGraphSearch.SCCResult;
+
+/**
+ * Tarjan graph search tests.
+ */
+public class TarjanGraphSearchTest extends GraphTest {
+
+    private void validate(SCCResult<TestVertex, TestEdge> result, int cc) {
+        System.out.println("Cluster count: " + result.clusterVertexes().size());
+        System.out.println("Clusters: " + result.clusterVertexes());
+        assertEquals("incorrect cluster count", cc, result.clusterCount());
+    }
+
+    private void validate(SCCResult<TestVertex, TestEdge> result,
+                          int i, int vc, int ec) {
+        assertEquals("incorrect cluster count", vc, result.clusterVertexes().get(i).size());
+        assertEquals("incorrect edge count", ec, result.clusterEdges().get(i).size());
+    }
+
+    @Test
+    public void basic() {
+        graph = new AdjacencyListsGraph<>(vertexes(), edges());
+        TarjanGraphSearch<TestVertex, TestEdge> gs = new TarjanGraphSearch<>();
+        SCCResult<TestVertex, TestEdge> result = gs.search(graph, null);
+        validate(result, 6);
+    }
+
+    @Test
+    public void singleCluster() {
+        graph = new AdjacencyListsGraph<>(vertexes(),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(B, C, 1),
+                                             new TestEdge(C, D, 1),
+                                             new TestEdge(D, E, 1),
+                                             new TestEdge(E, F, 1),
+                                             new TestEdge(F, G, 1),
+                                             new TestEdge(G, H, 1),
+                                             new TestEdge(H, A, 1)));
+
+        TarjanGraphSearch<TestVertex, TestEdge> gs = new TarjanGraphSearch<>();
+        SCCResult<TestVertex, TestEdge> result = gs.search(graph, null);
+        validate(result, 1);
+        validate(result, 0, 8, 8);
+    }
+
+    @Test
+    public void twoUnconnectedCluster() {
+        graph = new AdjacencyListsGraph<>(vertexes(),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(B, C, 1),
+                                             new TestEdge(C, D, 1),
+                                             new TestEdge(D, A, 1),
+                                             new TestEdge(E, F, 1),
+                                             new TestEdge(F, G, 1),
+                                             new TestEdge(G, H, 1),
+                                             new TestEdge(H, E, 1)));
+        TarjanGraphSearch<TestVertex, TestEdge> gs = new TarjanGraphSearch<>();
+        SCCResult<TestVertex, TestEdge> result = gs.search(graph, null);
+        validate(result, 2);
+        validate(result, 0, 4, 4);
+        validate(result, 1, 4, 4);
+    }
+
+    @Test
+    public void twoWeaklyConnectedClusters() {
+        graph = new AdjacencyListsGraph<>(vertexes(),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(B, C, 1),
+                                             new TestEdge(C, D, 1),
+                                             new TestEdge(D, A, 1),
+                                             new TestEdge(E, F, 1),
+                                             new TestEdge(F, G, 1),
+                                             new TestEdge(G, H, 1),
+                                             new TestEdge(H, E, 1),
+                                             new TestEdge(B, E, 1)));
+        TarjanGraphSearch<TestVertex, TestEdge> gs = new TarjanGraphSearch<>();
+        SCCResult<TestVertex, TestEdge> result = gs.search(graph, null);
+        validate(result, 2);
+        validate(result, 0, 4, 4);
+        validate(result, 1, 4, 4);
+    }
+
+    @Test
+    public void twoClustersConnectedWithIgnoredEdges() {
+        graph = new AdjacencyListsGraph<>(vertexes(),
+                                          of(new TestEdge(A, B, 1),
+                                             new TestEdge(B, C, 1),
+                                             new TestEdge(C, D, 1),
+                                             new TestEdge(D, A, 1),
+                                             new TestEdge(E, F, 1),
+                                             new TestEdge(F, G, 1),
+                                             new TestEdge(G, H, 1),
+                                             new TestEdge(H, E, 1),
+                                             new TestEdge(B, E, -1),
+                                             new TestEdge(E, B, -1)));
+
+        TarjanGraphSearch<TestVertex, TestEdge> gs = new TarjanGraphSearch<>();
+        SCCResult<TestVertex, TestEdge> result = gs.search(graph, weight);
+        validate(result, 2);
+        validate(result, 0, 4, 4);
+        validate(result, 1, 4, 4);
+    }
+
+}