diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/pom.xml b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/pom.xml
index 8658e448c12..8035f5722f5 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/pom.xml
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/pom.xml
@@ -51,6 +51,19 @@
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>org.apache.hadoop</groupId>
+      <artifactId>hadoop-auth</artifactId>
+      <type>test-jar</type>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.hadoop</groupId>
+      <artifactId>hadoop-minikdc</artifactId>
+      <scope>provided</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.mockito</groupId>
       <artifactId>mockito-all</artifactId>
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/amfilter/AmIpFilter.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/amfilter/AmIpFilter.java
index ac4afa845cd..b5e7ef66105 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/amfilter/AmIpFilter.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/amfilter/AmIpFilter.java
@@ -20,6 +20,7 @@ package org.apache.hadoop.yarn.server.webproxy.amfilter;
 
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.yarn.server.webproxy.ProxyUtils;
 import org.apache.hadoop.yarn.server.webproxy.WebAppProxyServlet;
 import org.slf4j.Logger;
@@ -214,15 +215,25 @@ public class AmIpFilter implements Filter {
     return addr;
   }
 
-  private boolean isValidUrl(String url) {
+  @VisibleForTesting
+  public boolean isValidUrl(String url) {
     boolean isValid = false;
     try {
-      HttpURLConnection conn =
-          (HttpURLConnection) new URL(url).openConnection();
+      HttpURLConnection conn = (HttpURLConnection) new URL(url)
+          .openConnection();
       conn.connect();
       isValid = conn.getResponseCode() == HttpURLConnection.HTTP_OK;
+      // If security is enabled, any valid RM which can give 401 Unauthorized is
+      // good enough to access. Since AM doesn't have enough credential, auth
+      // cannot be completed and hence 401 is fine in such case.
+      if (!isValid && UserGroupInformation.isSecurityEnabled()) {
+        isValid = (conn
+            .getResponseCode() == HttpURLConnection.HTTP_UNAUTHORIZED)
+            || (conn.getResponseCode() == HttpURLConnection.HTTP_FORBIDDEN);
+        return isValid;
+      }
     } catch (Exception e) {
-      LOG.debug("Failed to connect to " + url + ": " + e.toString());
+      LOG.warn("Failed to connect to " + url + ": " + e.toString());
     }
     return isValid;
   }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/test/java/org/apache/hadoop/yarn/server/webproxy/amfilter/TestSecureAmFilter.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/test/java/org/apache/hadoop/yarn/server/webproxy/amfilter/TestSecureAmFilter.java
new file mode 100644
index 00000000000..e87b76541e5
--- /dev/null
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/test/java/org/apache/hadoop/yarn/server/webproxy/amfilter/TestSecureAmFilter.java
@@ -0,0 +1,159 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.hadoop.yarn.server.webproxy.amfilter;
+
+import java.io.File;
+import java.net.URI;
+import java.net.URL;
+import java.util.Set;
+import java.util.HashSet;
+import java.util.HashMap;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+import org.apache.hadoop.http.HttpServer2;
+import org.apache.hadoop.minikdc.MiniKdc;
+import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.authentication.KerberosTestUtils;
+import org.apache.hadoop.security.authorize.AccessControlList;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.security.http.RMAuthenticationFilterInitializer;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.mockito.Mockito;
+
+/**
+ * Test AmIpFilter. Requests to a no declared hosts should has way through
+ * proxy. Another requests can be filtered with (without) user name.
+ *
+ */
+public class TestSecureAmFilter {
+
+  private String proxyHost = "localhost";
+  private static final File TEST_ROOT_DIR = new File("target",
+      TestSecureAmFilter.class.getName() + "-root");
+  private static File httpSpnegoKeytabFile = new File(
+      KerberosTestUtils.getKeytabFile());
+  private static Configuration rmconf = new Configuration();
+  private static String httpSpnegoPrincipal = KerberosTestUtils
+      .getServerPrincipal();
+  private static boolean miniKDCStarted = false;
+  private static MiniKdc testMiniKDC;
+
+  @BeforeClass
+  public static void setUp() {
+    rmconf.setBoolean(YarnConfiguration.YARN_ACL_ENABLE, true);
+    rmconf.set(CommonConfigurationKeysPublic.HADOOP_SECURITY_AUTHENTICATION,
+        "kerberos");
+    rmconf.setBoolean(YarnConfiguration.RM_WEBAPP_DELEGATION_TOKEN_AUTH_FILTER,
+        true);
+    rmconf.set("hadoop.http.filter.initializers",
+        RMAuthenticationFilterInitializer.class.getName());
+    rmconf.set(YarnConfiguration.RM_WEBAPP_SPNEGO_USER_NAME_KEY,
+        httpSpnegoPrincipal);
+    rmconf.set(YarnConfiguration.RM_KEYTAB,
+        httpSpnegoKeytabFile.getAbsolutePath());
+    rmconf.set(YarnConfiguration.RM_WEBAPP_SPNEGO_KEYTAB_FILE_KEY,
+        httpSpnegoKeytabFile.getAbsolutePath());
+    UserGroupInformation.setConfiguration(rmconf);
+    try {
+      testMiniKDC = new MiniKdc(MiniKdc.createConf(), TEST_ROOT_DIR);
+      setupKDC();
+    } catch (Exception e) {
+      assertTrue("Couldn't create MiniKDC", false);
+    }
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    if (testMiniKDC != null) {
+      testMiniKDC.stop();
+    }
+  }
+
+  private static void setupKDC() throws Exception {
+    if (!miniKDCStarted) {
+      testMiniKDC.start();
+      getKdc().createPrincipal(httpSpnegoKeytabFile, "HTTP/localhost");
+      miniKDCStarted = true;
+    }
+  }
+
+  private static MiniKdc getKdc() {
+    return testMiniKDC;
+  }
+
+  private class TestAmIpFilter extends AmIpFilter {
+
+    private Set<String> proxyAddresses = null;
+
+    protected Set<String> getProxyAddresses() {
+      if (proxyAddresses == null) {
+        proxyAddresses = new HashSet<String>();
+      }
+      proxyAddresses.add(proxyHost);
+      return proxyAddresses;
+    }
+  }
+
+  @Test
+  public void testFindRedirectUrl() throws Exception {
+    final String rm1 = "rm1";
+    final String rm2 = "rm2";
+    // generate a valid URL
+    final String rm1Url = startSecureHttpServer();
+    // invalid url
+    final String rm2Url = "host2:8088";
+
+    TestAmIpFilter filter = new TestAmIpFilter();
+    TestAmIpFilter spy = Mockito.spy(filter);
+    // make sure findRedirectUrl() go to HA branch
+    spy.proxyUriBases = new HashMap<>();
+    spy.proxyUriBases.put(rm1, rm1Url);
+    spy.proxyUriBases.put(rm2, rm2Url);
+    spy.rmUrls = new String[] {rm1, rm2};
+
+    assertTrue(spy.isValidUrl(rm1Url));
+    assertFalse(spy.isValidUrl(rm2Url));
+    assertEquals(spy.findRedirectUrl(), rm1Url);
+  }
+
+  private String startSecureHttpServer() throws Exception {
+    HttpServer2.Builder builder = new HttpServer2.Builder()
+        .setName("test").setConf(rmconf)
+        .addEndpoint(new URI("http://localhost")).setACL(
+            new AccessControlList(rmconf.get(YarnConfiguration.YARN_ADMIN_ACL,
+                YarnConfiguration.DEFAULT_YARN_ADMIN_ACL)));
+
+    builder.setUsernameConfKey(YarnConfiguration.RM_WEBAPP_SPNEGO_USER_NAME_KEY)
+        .setKeytabConfKey(YarnConfiguration.RM_WEBAPP_SPNEGO_KEYTAB_FILE_KEY)
+        .setSecurityEnabled(UserGroupInformation.isSecurityEnabled());
+    HttpServer2 server = builder.build();
+    server.start();
+    URL baseUrl = new URL(
+        "http://" + NetUtils.getHostPortString(server.getConnectorAddress(0)));
+    return baseUrl.toString();
+  }
+}
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/test/resources/krb5.conf b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/test/resources/krb5.conf
new file mode 100644
index 00000000000..6cdd3d6923f
--- /dev/null
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/test/resources/krb5.conf
@@ -0,0 +1,33 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+#
+
+[libdefaults]
+   default_realm = APACHE.ORG
+   extra_addresses = 127.0.0.1
+   kdc_realm = _REALM_
+   udp_preference_limit = _UDP_LIMIT_
+   #_KDC_TCP_PORT_
+   #_KDC_UDP_PORT_
+
+[realms]
+   _REALM_ = {
+       admin_server = localhost:_KDC_PORT_
+       kdc = localhost:_KDC_PORT_
+   }
+[domain_realm]
+   localhost = _REALM_