diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
index f5855e8..f68b165 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
@@ -16,8 +16,19 @@
 
 package org.onosproject.yangutils.parser.impl.listeners;
 
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.ParsableDataType;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation;
+import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction;
+import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType;
+import org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -55,18 +66,41 @@
      */
     public static void processConfigEntry(TreeWalkListener listener,
                                              GeneratedYangParser.ConfigStatementContext ctx) {
-        // TODO method implementation
-    }
+        boolean isConfig = false;
 
-    /**
-     * It is called when parser exits from grammar rule (config), it performs
-     * validation and updates the data model tree.
-     *
-     * @param listener listener's object.
-     * @param ctx context object of the grammar rule.
-     */
-    public static void processConfigExit(TreeWalkListener listener,
-                                            GeneratedYangParser.ConfigStatementContext ctx) {
-        // TODO method implementation
+        // Check for stack to be non empty.
+        ListenerValidation.checkStackIsNotEmpty(listener, ListenerErrorType.MISSING_HOLDER,
+                ParsableDataType.CONFIG_DATA, "", ListenerErrorLocation.ENTRY);
+
+        if (ctx.TRUE_KEYWORD() != null) {
+            isConfig = true;
+        }
+
+        Parsable tmpData = listener.getParsedDataStack().peek();
+        switch (tmpData.getParsableDataType()) {
+            case LEAF_DATA:
+                YangLeaf leaf = (YangLeaf) tmpData;
+                leaf.setConfig(isConfig);
+                break;
+            case CONTAINER_DATA:
+                YangContainer container = (YangContainer) tmpData;
+                container.setConfig(isConfig);
+                break;
+            case LEAF_LIST_DATA:
+                YangLeafList leafList = (YangLeafList) tmpData;
+                leafList.setConfig(isConfig);
+                break;
+            case LIST_DATA:
+                YangList yangList = (YangList) tmpData;
+                yangList.setConfig(isConfig);
+                break;
+            case CHOICE_DATA: // TODO
+                break;
+            default:
+                throw new ParserException(ListenerErrorMessageConstruction
+                        .constructListenerErrorMessage(ListenerErrorType.INVALID_HOLDER,
+                                ParsableDataType.CONFIG_DATA,
+                                "", ListenerErrorLocation.ENTRY));
+        }
     }
 }
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