diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 9ac62a72521..7fee56d9648 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -706,6 +706,9 @@ Release 2.5.0 - UNRELEASED
     HDFS-6717. JIRA HDFS-5804 breaks default nfs-gateway behavior for unsecured config
     (brandonli)
 
+    HDFS-6768. Fix a few unit tests that use hard-coded port numbers. (Arpit
+    Agarwal)
+
   BREAKDOWN OF HDFS-2006 SUBTASKS AND RELATED JIRAS
 
     HDFS-6299. Protobuf for XAttr and client-side implementation. (Yi Liu via umamahesh)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestGenericRefresh.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestGenericRefresh.java
index 664a478f27a..3c73c28c2a6 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestGenericRefresh.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestGenericRefresh.java
@@ -47,7 +47,6 @@ import org.mockito.Mockito;
 public class TestGenericRefresh {
   private static MiniDFSCluster cluster;
   private static Configuration config;
-  private static final int NNPort = 54222;
 
   private static RefreshHandler firstHandler;
   private static RefreshHandler secondHandler;
@@ -57,8 +56,8 @@ public class TestGenericRefresh {
     config = new Configuration();
     config.set("hadoop.security.authorization", "true");
 
-    FileSystem.setDefaultUri(config, "hdfs://localhost:" + NNPort);
-    cluster = new MiniDFSCluster.Builder(config).nameNodePort(NNPort).build();
+    FileSystem.setDefaultUri(config, "hdfs://localhost:0");
+    cluster = new MiniDFSCluster.Builder(config).build();
     cluster.waitActive();
   }
 
@@ -103,7 +102,8 @@ public class TestGenericRefresh {
   @Test
   public void testInvalidIdentifier() throws Exception {
     DFSAdmin admin = new DFSAdmin(config);
-    String [] args = new String[]{"-refresh", "localhost:" + NNPort, "unregisteredIdentity"};
+    String [] args = new String[]{"-refresh", "localhost:" + 
+        cluster.getNameNodePort(), "unregisteredIdentity"};
     int exitCode = admin.run(args);
     assertEquals("DFSAdmin should fail due to no handler registered", -1, exitCode);
   }
@@ -111,7 +111,8 @@ public class TestGenericRefresh {
   @Test
   public void testValidIdentifier() throws Exception {
     DFSAdmin admin = new DFSAdmin(config);
-    String[] args = new String[]{"-refresh", "localhost:" + NNPort, "firstHandler"};
+    String[] args = new String[]{"-refresh",
+        "localhost:" + cluster.getNameNodePort(), "firstHandler"};
     int exitCode = admin.run(args);
     assertEquals("DFSAdmin should succeed", 0, exitCode);
 
@@ -124,11 +125,13 @@ public class TestGenericRefresh {
   @Test
   public void testVariableArgs() throws Exception {
     DFSAdmin admin = new DFSAdmin(config);
-    String[] args = new String[]{"-refresh", "localhost:" + NNPort, "secondHandler", "one"};
+    String[] args = new String[]{"-refresh", "localhost:" +
+        cluster.getNameNodePort(), "secondHandler", "one"};
     int exitCode = admin.run(args);
     assertEquals("DFSAdmin should return 2", 2, exitCode);
 
-    exitCode = admin.run(new String[]{"-refresh", "localhost:" + NNPort, "secondHandler", "one", "two"});
+    exitCode = admin.run(new String[]{"-refresh", "localhost:" +
+        cluster.getNameNodePort(), "secondHandler", "one", "two"});
     assertEquals("DFSAdmin should now return 3", 3, exitCode);
 
     Mockito.verify(secondHandler).handleRefresh("secondHandler", new String[]{"one"});
@@ -141,7 +144,8 @@ public class TestGenericRefresh {
 
     // And now this should fail
     DFSAdmin admin = new DFSAdmin(config);
-    String[] args = new String[]{"-refresh", "localhost:" + NNPort, "firstHandler"};
+    String[] args = new String[]{"-refresh", "localhost:" +
+        cluster.getNameNodePort(), "firstHandler"};
     int exitCode = admin.run(args);
     assertEquals("DFSAdmin should return -1", -1, exitCode);
   }
@@ -161,7 +165,8 @@ public class TestGenericRefresh {
 
     // this should trigger both
     DFSAdmin admin = new DFSAdmin(config);
-    String[] args = new String[]{"-refresh", "localhost:" + NNPort, "sharedId", "one"};
+    String[] args = new String[]{"-refresh", "localhost:" +
+        cluster.getNameNodePort(), "sharedId", "one"};
     int exitCode = admin.run(args);
     assertEquals(-1, exitCode); // -1 because one of the responses is unregistered
 
@@ -189,7 +194,8 @@ public class TestGenericRefresh {
 
     // We refresh both
     DFSAdmin admin = new DFSAdmin(config);
-    String[] args = new String[]{"-refresh", "localhost:" + NNPort, "shared"};
+    String[] args = new String[]{"-refresh", "localhost:" +
+        cluster.getNameNodePort(), "shared"};
     int exitCode = admin.run(args);
     assertEquals(-1, exitCode); // We get -1 because of our logic for melding non-zero return codes
 
@@ -215,7 +221,8 @@ public class TestGenericRefresh {
     RefreshRegistry.defaultRegistry().register("exceptional", otherExceptionalHandler);
 
     DFSAdmin admin = new DFSAdmin(config);
-    String[] args = new String[]{"-refresh", "localhost:" + NNPort, "exceptional"};
+    String[] args = new String[]{"-refresh", "localhost:" +
+        cluster.getNameNodePort(), "exceptional"};
     int exitCode = admin.run(args);
     assertEquals(-1, exitCode); // Exceptions result in a -1
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestRefreshCallQueue.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestRefreshCallQueue.java
index 9b0acbc8ca6..f66f9b6105f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestRefreshCallQueue.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestRefreshCallQueue.java
@@ -24,6 +24,8 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.IOException;
+import java.net.BindException;
+import java.util.Random;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 
@@ -42,24 +44,42 @@ public class TestRefreshCallQueue {
   private FileSystem fs;
   static int mockQueueConstructions;
   static int mockQueuePuts;
-  private static final int NNPort = 54222;
-  private static String CALLQUEUE_CONFIG_KEY = "ipc." + NNPort + ".callqueue.impl";
+  private String callQueueConfigKey = "";
+  private final Random rand = new Random();
 
   @Before
   public void setUp() throws Exception {
     // We want to count additional events, so we reset here
     mockQueueConstructions = 0;
     mockQueuePuts = 0;
+    int portRetries = 5;
+    int nnPort;
 
-    config = new Configuration();
-    config.setClass(CALLQUEUE_CONFIG_KEY,
-        MockCallQueue.class, BlockingQueue.class);
-    config.set("hadoop.security.authorization", "true");
+    for (; portRetries > 0; --portRetries) {
+      // Pick a random port in the range [30000,60000).
+      nnPort = 30000 + rand.nextInt(30000);  
+      config = new Configuration();
+      callQueueConfigKey = "ipc." + nnPort + ".callqueue.impl";
+      config.setClass(callQueueConfigKey,
+          MockCallQueue.class, BlockingQueue.class);
+      config.set("hadoop.security.authorization", "true");
 
-    FileSystem.setDefaultUri(config, "hdfs://localhost:" + NNPort);
-    fs = FileSystem.get(config);
-    cluster = new MiniDFSCluster.Builder(config).nameNodePort(NNPort).build();
-    cluster.waitActive();
+      FileSystem.setDefaultUri(config, "hdfs://localhost:" + nnPort);
+      fs = FileSystem.get(config);
+      
+      try {
+        cluster = new MiniDFSCluster.Builder(config).nameNodePort(nnPort).build();
+        cluster.waitActive();
+        break;
+      } catch (BindException be) {
+        // Retry with a different port number.
+      }
+    }
+    
+    if (portRetries == 0) {
+      // Bail if we get very unlucky with our choice of ports.
+      fail("Failed to pick an ephemeral port for the NameNode RPC server.");
+    }
   }
 
   @After
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockRecovery.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockRecovery.java
index a9e95da4df1..f627c42c619 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockRecovery.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockRecovery.java
@@ -587,7 +587,6 @@ public class TestBlockRecovery {
     Configuration conf = new HdfsConfiguration();
     conf.set(DFSConfigKeys.DFS_DATANODE_XCEIVER_STOP_TIMEOUT_MILLIS_KEY, "1000");
     MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
-        .nnTopology(MiniDFSNNTopology.simpleSingleNN(8020, 50070))
         .numDataNodes(1).build();
     try {
       cluster.waitClusterUp();