diff --git a/protocols/snmp/ctl/src/main/java/org/onosproject/snmp/ctl/DefaultSnmpController.java b/protocols/snmp/ctl/src/main/java/org/onosproject/snmp/ctl/DefaultSnmpController.java
index 35556cd..e82a583 100644
--- a/protocols/snmp/ctl/src/main/java/org/onosproject/snmp/ctl/DefaultSnmpController.java
+++ b/protocols/snmp/ctl/src/main/java/org/onosproject/snmp/ctl/DefaultSnmpController.java
@@ -52,10 +52,10 @@
     private final Logger log = LoggerFactory
             .getLogger(getClass());
 
-    private ISnmpSessionFactory sessionFactory;
+    protected ISnmpSessionFactory sessionFactory;
 
-    private final Map<DeviceId, ISnmpSession> sessionMap = new HashMap<>();
-    protected Map<DeviceId, SnmpDevice> snmpDeviceMap = new ConcurrentHashMap<>();
+    protected final Map<DeviceId, ISnmpSession> sessionMap = new HashMap<>();
+    protected final Map<DeviceId, SnmpDevice> snmpDeviceMap = new ConcurrentHashMap<>();
 
     @Activate
     public void activate(ComponentContext context) {
@@ -66,6 +66,7 @@
 
     @Deactivate
     public void deactivate() {
+        sessionMap.clear();
         snmpDeviceMap.clear();
         log.info("Stopped");
     }