diff --git a/src/share/classes/sun/security/krb5/Config.java b/src/share/classes/sun/security/krb5/Config.java
index e036776f53e1c964c6e164f1355dd1e48a57ba3a..8adcba81f5327bdd8656df3d6b0d3df4ae640797 100644
--- a/src/share/classes/sun/security/krb5/Config.java
+++ b/src/share/classes/sun/security/krb5/Config.java
@@ -123,7 +123,7 @@ public class Config {
             java.security.AccessController.doPrivileged(
                 new sun.security.action.GetPropertyAction
                     ("java.security.krb5.kdc"));
-         defaultRealm =
+        defaultRealm =
             java.security.AccessController.doPrivileged(
                 new sun.security.action.GetPropertyAction
                     ("java.security.krb5.realm"));
@@ -134,6 +134,16 @@ public class Config {
                  "java.security.krb5.realm both must be set or " +
                  "neither must be set.");
         }
+
+        // Read the Kerberos configuration file
+        try {
+            Vector<String> configFile;
+            configFile = loadConfigFile();
+            stanzaTable = parseStanzaTable(configFile);
+        } catch (IOException ioe) {
+            // No krb5.conf, no problem. We'll use DNS etc.
+        }
+
         if (kdchost != null) {
             /*
              * If configuration information is only specified by
@@ -141,22 +151,19 @@ public class Config {
              * java.security.krb5.realm, we put both in the hashtable
              * under [libdefaults].
              */
-            Hashtable<String,String> kdcs = new Hashtable<String,String> ();
+            if (stanzaTable == null) {
+                stanzaTable = new Hashtable<String,Object> ();
+            }
+            Hashtable<String,String> kdcs =
+                    (Hashtable<String,String>)stanzaTable.get("libdefaults");
+            if (kdcs == null) {
+                kdcs = new Hashtable<String,String> ();
+                stanzaTable.put("libdefaults", kdcs);
+            }
             kdcs.put("default_realm", defaultRealm);
             // The user can specify a list of kdc hosts separated by ":"
             kdchost = kdchost.replace(':', ' ');
             kdcs.put("kdc", kdchost);
-            stanzaTable = new Hashtable<String,Object> ();
-            stanzaTable.put("libdefaults", kdcs);
-        } else {
-            // Read the Kerberos configuration file
-            try {
-                Vector<String> configFile;
-                configFile = loadConfigFile();
-                stanzaTable = parseStanzaTable(configFile);
-            } catch (IOException ioe) {
-                // No krb5.conf, no problem. We'll use DNS etc.
-            }
         }
     }
 
@@ -294,7 +301,7 @@ public class Config {
          * hashtable.
          */
         if (name.equalsIgnoreCase("kdc") &&
-            (!section.equalsIgnoreCase("libdefaults")) &&
+            (section.equalsIgnoreCase(getDefault("default_realm", "libdefaults"))) &&
             (java.security.AccessController.doPrivileged(
                 new sun.security.action.
                 GetPropertyAction("java.security.krb5.kdc")) != null)) {
diff --git a/test/sun/security/krb5/ConfPlusProp.java b/test/sun/security/krb5/ConfPlusProp.java
new file mode 100644
index 0000000000000000000000000000000000000000..b1ea2ca5e7526013fc7b48534d8dca7c5dd29319
--- /dev/null
+++ b/test/sun/security/krb5/ConfPlusProp.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+/*
+ * @test
+ * @bug 6857795
+ * @summary krb5.conf ignored if system properties on realm and kdc are provided
+ */
+
+import sun.security.krb5.Config;
+import sun.security.krb5.KrbException;
+
+public class ConfPlusProp {
+    public static void main(String[] args) throws Exception {
+        System.setProperty("java.security.krb5.realm", "R2");
+        System.setProperty("java.security.krb5.kdc", "k2");
+
+        // Point to a file with existing default_realm
+        System.setProperty("java.security.krb5.conf",
+                System.getProperty("test.src", ".") +"/confplusprop.conf");
+        Config config = Config.getInstance();
+
+        if (!config.getDefaultRealm().equals("R2")) {
+            throw new Exception("Default realm error");
+        }
+        if (!config.getKDCList("R1").equals("k1")) {
+            throw new Exception("R1 kdc error");
+        }
+        if (!config.getKDCList("R2").equals("k2")) {
+            throw new Exception("R2 kdc error");
+        }
+        if (!config.getDefault("forwardable", "libdefaults").equals("well")) {
+            throw new Exception("Extra config error");
+        }
+
+        // Point to a file with no libdefaults
+        System.setProperty("java.security.krb5.conf",
+                System.getProperty("test.src", ".") +"/confplusprop2.conf");
+        Config.refresh();
+
+        config = Config.getInstance();
+
+        if (!config.getDefaultRealm().equals("R2")) {
+            throw new Exception("Default realm error again");
+        }
+        if (!config.getKDCList("R1").equals("k12")) {
+            throw new Exception("R1 kdc error");
+        }
+        if (!config.getKDCList("R2").equals("k2")) {
+            throw new Exception("R2 kdc error");
+        }
+
+        // Point to a non-existing file
+        System.setProperty("java.security.krb5.conf", "i-am-not-a file");
+        Config.refresh();
+
+        config = Config.getInstance();
+
+        if (!config.getDefaultRealm().equals("R2")) {
+            throw new Exception("Default realm error");
+        }
+        try {
+            config.getKDCList("R1");
+            throw new Exception("R1 is nowhere");
+        } catch (KrbException ke) {
+            // OK
+        }
+        if (!config.getKDCList("R2").equals("k2")) {
+            throw new Exception("R2 kdc error");
+        }
+        if (config.getDefault("forwardable", "libdefaults") != null) {
+            throw new Exception("Extra config error");
+        }
+    }
+}
diff --git a/test/sun/security/krb5/confplusprop.conf b/test/sun/security/krb5/confplusprop.conf
new file mode 100644
index 0000000000000000000000000000000000000000..80c925b14cd9ecce85d656c02256cd7c07b47e12
--- /dev/null
+++ b/test/sun/security/krb5/confplusprop.conf
@@ -0,0 +1,11 @@
+[libdefaults]
+default_realm = R1
+forwardable = well
+
+[realms]
+R1 = {
+   kdc = k1
+}
+R2 = {
+   kdc = old
+}
diff --git a/test/sun/security/krb5/confplusprop2.conf b/test/sun/security/krb5/confplusprop2.conf
new file mode 100644
index 0000000000000000000000000000000000000000..df00eccbccfdafa995b21634bb43e2738d26ca08
--- /dev/null
+++ b/test/sun/security/krb5/confplusprop2.conf
@@ -0,0 +1,7 @@
+[realms]
+R1 = {
+   kdc = k12
+}
+R2 = {
+   kdc = old
+}