diff --git a/internal/pkg/controller/device.go b/internal/pkg/controller/device.go
index bdac105..abf3108 100644
--- a/internal/pkg/controller/device.go
+++ b/internal/pkg/controller/device.go
@@ -199,8 +199,8 @@
 func (d *Device) GetFlow(cookie uint64) (*of.VoltSubFlow, bool) {
 	d.flowLock.RLock()
 	defer d.flowLock.RUnlock()
-	logger.Debugw(ctx, "Get Flow", log.Fields{"Cookie": cookie})
 	flow, ok := d.flows[cookie]
+	logger.Debugw(ctx, "Get Flow", log.Fields{"Cookie": cookie})
 	return flow, ok
 }
 
@@ -235,8 +235,11 @@
 	d.flowLock.Lock()
 	defer d.flowLock.Unlock()
 	logger.Debugw(ctx, "AddFlow to device", log.Fields{"Cookie": flow.Cookie})
-	if _, ok := d.flows[flow.Cookie]; ok {
-		return errors.New(ErrDuplicateFlow)
+	if dbFlow, ok := d.flows[flow.Cookie]; ok {
+		// In case of ONU reboot after flow delete failure, try to install flow in the device by checking for previous flow state
+		if dbFlow.State != of.FlowDelFailure {
+			return errors.New(ErrDuplicateFlow)
+		}
 	}
 	d.flows[flow.Cookie] = flow
 	d.AddFlowToDb(cntx, flow)
@@ -277,7 +280,7 @@
 		return false
 	} else if flow.OldCookie != 0 && flow.Cookie != flow.OldCookie {
 		if _, ok := d.flows[flow.OldCookie]; ok {
-			logger.Debugw(ctx, "Flow present with old cookie", log.Fields{"OldCookie": flow.OldCookie})
+			logger.Warnw(ctx, "Flow present with old cookie", log.Fields{"OldCookie": flow.OldCookie})
 			return true
 		}
 	}
@@ -487,13 +490,14 @@
 // Inform the application if the port is successfully added
 func (d *Device) AddPort(cntx context.Context, mp *ofp.OfpPort) error {
 	d.portLock.Lock()
-	defer d.portLock.Unlock()
 	id := mp.PortNo
 	name := mp.Name
 	if _, ok := d.PortsByID[id]; ok {
+		d.portLock.Unlock()
 		return errors.New(Duplicate_Port)
 	}
 	if _, ok := d.PortsByName[name]; ok {
+		d.portLock.Unlock()
 		return errors.New(Duplicate_Port)
 	}
 
@@ -501,6 +505,7 @@
 	d.PortsByID[id] = p
 	d.PortsByName[name] = p
 	d.WritePortToDb(cntx, p)
+	d.portLock.Unlock()
 	GetController().PortAddInd(cntx, d.ID, p.ID, p.Name)
 	logger.Infow(ctx, "Added Port", log.Fields{"Device": d.ID, "Port": id})
 	return nil
@@ -533,6 +538,19 @@
 	return nil
 }
 
+// CheckAndDeletePort deletes the port if the port name matches with VGC and one sent from voltha in OFPPR_DELETE
+func (d *Device) CheckAndDeletePort(cntx context.Context, portNo uint32, portName string) {
+	if p := d.GetPortByID(portNo); p != nil {
+		if p.Name != portName {
+			logger.Warnw(ctx, "Dropping Del Port event: Port name mismatch", log.Fields{"vgcPortName": p.Name, "ofpPortName": portName, "ID": p.ID})
+			return
+		}
+		if err := d.DelPort(cntx, portNo, portName); err != nil {
+			logger.Warnw(ctx, "DelPort Failed", log.Fields{"Port No": portNo, "Error": err})
+		}
+	}
+}
+
 // UpdatePortByName is utility to update the port by Name
 func (d *Device) UpdatePortByName(cntx context.Context, name string, port uint32) {
 	d.portLock.Lock()
@@ -796,15 +814,11 @@
 func (d *Device) ProcessPortUpdate(cntx context.Context, portName string, port uint32, state uint32) {
 	if p := d.GetPortByName(portName); p != nil {
 		if p.ID != port {
-			logger.Infow(ctx, "Port ID update indication", log.Fields{"Port": p.Name, "Old PortID": p.ID, "New Port ID": port})
-			if p.State != PortStateDown {
-				logger.Errorw(ctx, "Port ID update failed. Port State UP", log.Fields{"Port": p})
-				return
-			}
-			d.UpdatePortByName(cntx, portName, port)
-			logger.Errorw(ctx, "Port ID Updated", log.Fields{"Port": p})
+			logger.Warnw(ctx, "Port update indication received with mismatching ID", log.Fields{"Port": p.Name, "Old PortID": p.ID, "New Port ID": port})
+			return
+			//Do not process port update received from change event, as we will only handle port updates during polling
 		}
-		d.ProcessPortState(cntx, port, state)
+		d.ProcessPortState(cntx, port, state, portName)
 	}
 }
 
@@ -824,7 +838,7 @@
 
 // ProcessPortState deals with the change in port status and taking action
 // based on the new state and the old state
-func (d *Device) ProcessPortState(cntx context.Context, port uint32, state uint32) {
+func (d *Device) ProcessPortState(cntx context.Context, port uint32, state uint32, portName string) {
 	if d.State != DeviceStateUP && !util.IsNniPort(port) {
 		logger.Warnw(ctx, "Ignore Port State Processing - Device not UP", log.Fields{"Device": d.ID, "Port": port, "DeviceState": d.State})
 		return
@@ -832,6 +846,10 @@
 	if p := d.GetPortByID(port); p != nil {
 		logger.Infow(ctx, "Port State Processing", log.Fields{"Received": state, "Current": p.State})
 
+		if p.Name != portName {
+			logger.Warnw(ctx, "Dropping Port State processing: Port name does not match", log.Fields{"vgcPort": p.Name, "ofpPort": portName, "ID": port})
+			return
+		}
 		// Avoid blind initialization as the current tasks in the queue will be lost
 		// Eg: Service Del followed by Port Down - The flows will be dangling
 		// Eg: NNI Down followed by NNI UP - Mcast data flows will be dangling
@@ -1059,19 +1077,43 @@
 	return false
 }
 
-func (d *Device) triggerFlowNotification(cntx context.Context, cookie uint64, oper of.Command, bwDetails of.BwAvailDetails, err error, sendFlowNotif bool) {
-	flow, _ := d.GetFlow(cookie)
-	d.triggerFlowResultNotification(cntx, cookie, flow, oper, bwDetails, err, sendFlowNotif)
+// IsFlowDelThresholdReached - check if the attempts for flow delete has reached threshold or not
+func (d *Device) IsFlowDelThresholdReached(flowCount uint32, cookie uint64) bool {
+	logger.Debugw(ctx, "Check flow delete threshold", log.Fields{"Cookie": cookie, "FlowCount": flowCount})
+	return flowCount >= GetController().GetMaxFlowRetryAttempt()
 }
 
-func (d *Device) triggerFlowResultNotification(cntx context.Context, cookie uint64, flow *of.VoltSubFlow, oper of.Command, bwDetails of.BwAvailDetails, err error, sendFlowNotif bool) {
+// IsFlowAddThresholdReached - check if the attempts for flow add has reached threshold or not
+func (d *Device) IsFlowAddThresholdReached(flowCount uint32, cookie uint64) bool {
+	logger.Debugw(ctx, "Check flow add threshold", log.Fields{"Cookie": cookie, "FlowCount": flowCount})
+	return flowCount >= GetController().GetMaxFlowRetryAttempt()
+}
+
+func (d *Device) UpdateFlowCount(cntx context.Context, cookie uint64) {
+	if dbFlow, ok := d.flows[cookie]; ok {
+		dbFlow.FlowCount++
+		d.AddFlowToDb(cntx, dbFlow)
+	}
+}
+
+func (d *Device) triggerFlowNotification(cntx context.Context, cookie uint64, oper of.Command, bwDetails of.BwAvailDetails, err error) {
+	flow, _ := d.GetFlow(cookie)
+	d.triggerFlowResultNotification(cntx, cookie, flow, oper, bwDetails, err)
+}
+
+func (d *Device) triggerFlowResultNotification(cntx context.Context, cookie uint64, flow *of.VoltSubFlow, oper of.Command, bwDetails of.BwAvailDetails, err error) {
 	statusCode, statusMsg := infraerror.GetErrorInfo(err)
 	success := isFlowOperSuccess(statusCode, oper)
 
-	updateFlow := func(cookie uint64, state int, reason string) {
-		if dbFlow, ok := d.GetFlow(cookie); ok {
+	updateFlowStatus := func(cookie uint64, state int, reason string) {
+		d.flowLock.Lock()
+		defer d.flowLock.Unlock()
+		if dbFlow, ok := d.flows[cookie]; ok {
 			dbFlow.State = uint8(state)
 			dbFlow.ErrorReason = reason
+			if state == of.FlowAddSuccess {
+				dbFlow.FlowCount = 0
+			}
 			d.AddFlowToDb(cntx, dbFlow)
 		}
 	}
@@ -1086,15 +1128,24 @@
 			state = of.FlowAddFailure
 			reason = statusMsg
 		}
-		updateFlow(cookie, state, reason)
-		logger.Debugw(ctx, "Updated Flow to DB", log.Fields{"Cookie": cookie, "State": state})
+		updateFlowStatus(cookie, state, reason)
+		logger.Debugw(ctx, "Add flow updated to DB", log.Fields{"Cookie": cookie, "State": state})
 	} else {
 		if success && flow != nil {
+			logger.Debugw(ctx, "Deleted flow from device and DB", log.Fields{"Cookie": cookie})
 			if err := d.DelFlow(cntx, flow); err != nil {
 				logger.Warnw(ctx, "Delete Flow Error", log.Fields{"Cookie": flow.Cookie, "Reason": err.Error()})
 			}
 		} else if !success {
-			updateFlow(cookie, of.FlowDelFailure, statusMsg)
+			if d.IsFlowDelThresholdReached(flow.FlowCount, flow.Cookie) {
+				logger.Debugw(ctx, "Deleted flow from device and DB after delete threshold reached", log.Fields{"Cookie": cookie})
+				if err := d.DelFlow(cntx, flow); err != nil {
+					logger.Warnw(ctx, "Delete Flow Error", log.Fields{"Cookie": flow.Cookie, "Reason": err.Error()})
+				}
+			} else {
+				updateFlowStatus(cookie, of.FlowDelFailure, statusMsg)
+				logger.Debugw(ctx, "Delete flow updated to DB", log.Fields{"Cookie": cookie})
+			}
 		}
 	}
 
@@ -1108,8 +1159,6 @@
 		AdditionalData: bwDetails,
 	}
 
-	if sendFlowNotif {
-		logger.Debugw(ctx, "Sending Flow Notification", log.Fields{"Cookie": cookie, "Error Code": statusCode, "FlowOp": oper})
-		GetController().ProcessFlowModResultIndication(cntx, flowResult)
-	}
+	logger.Debugw(ctx, "Sending Flow Notification", log.Fields{"Cookie": cookie, "Error Code": statusCode, "FlowOp": oper})
+	GetController().ProcessFlowModResultIndication(cntx, flowResult)
 }