testCnxManagerTimeout should use valid ip that is not reachable.

The random number returned can be signed hence negative and
for those cases test fails quickly. For a valid ip that is
not reachable ittakes a while longer to declare connection failure.

src/java/test/org/apache/zookeeper/test/CnxManagerTest.java

@@ -187,15 +187,13 @@ public void testCnxManager() throws Exception {
     @Test
     public void testCnxManagerTimeout() throws Exception {
         Random rand = new Random();
-        byte b = (byte) rand.nextInt();
-        int deadPort = PortAssignment.unique();
-        String deadAddress = "10.1.1." + b;
+        String deadAddress = "10.1.1." + (rand.nextInt(254) + 1);
 
         LOG.info("This is the dead address I'm trying: " + deadAddress);
 
         peers.put(Long.valueOf(2),
                 new QuorumServer(2,
-                        new ServerCfg(deadAddress, new InetSocketAddress(deadAddress, deadPort)),
+                        new ServerCfg(deadAddress, new InetSocketAddress(deadAddress, PortAssignment.unique())),
                         new ServerCfg(deadAddress, new InetSocketAddress(deadAddress, PortAssignment.unique())),
                         new ServerCfg(deadAddress, new InetSocketAddress(deadAddress, PortAssignment.unique()))));
         peerTmpdir[2] = ClientBase.createTmpDir();
@@ -213,7 +211,7 @@ public void testCnxManagerTimeout() throws Exception {
         cnxManager.toSend(2L, createMsg(ServerState.LOOKING.ordinal(), 1, -1, 1));
         long end = Time.currentElapsedTime();
 
-        if((end - begin) > 6000) Assert.fail("Waited more than necessary");
+        if((end - begin) > 15000) Assert.fail("Waited more than necessary");
         cnxManager.halt();
         Assert.assertFalse(cnxManager.listener.isAlive());
     }