diff --git a/python/ofagent/grpc_client.py b/python/ofagent/grpc_client.py
index 5a05696..b58612f 100755
--- a/python/ofagent/grpc_client.py
+++ b/python/ofagent/grpc_client.py
@@ -45,6 +45,12 @@
         self.grpc_timeout = grpc_timeout
         self.local_stub = VolthaServiceStub(channel)
 
+        # This is the vcore group to which an OFAgent is bound.
+        # It is the affinity router that forwards all OFAgent
+        # requests to the primary vcore in the group.
+        self.core_group_id = ''
+        self.CORE_GROUP_ID = 'voltha_backend_name'
+
         self.stopped = False
 
         self.packet_out_queue = Queue()  # queue to send out PacketOut msgs
@@ -81,7 +87,8 @@
         def stream_packets_out():
             generator = packet_generator()
             try:
-                self.local_stub.StreamPacketsOut(generator)
+                self.local_stub.StreamPacketsOut(generator,
+                                                 metadata=((self.CORE_GROUP_ID, self.core_group_id), ))
             except _Rendezvous, e:
                 log.error('grpc-exception', status=e.code())
                 if e.code() == StatusCode.UNAVAILABLE:
@@ -156,14 +163,16 @@
     def get_port(self, device_id, port_id):
         req = LogicalPortId(id=device_id, port_id=port_id)
         res = yield threads.deferToThread(
-            self.local_stub.GetLogicalDevicePort, req, timeout=self.grpc_timeout)
+            self.local_stub.GetLogicalDevicePort, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res)
 
     @inlineCallbacks
     def get_port_list(self, device_id):
         req = ID(id=device_id)
         res = yield threads.deferToThread(
-            self.local_stub.ListLogicalDevicePorts, req, timeout=self.grpc_timeout)
+            self.local_stub.ListLogicalDevicePorts, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res.items)
 
     @inlineCallbacks
@@ -173,7 +182,8 @@
             port_id=port_id
         )
         res = yield threads.deferToThread(
-            self.local_stub.EnableLogicalDevicePort, req, timeout=self.grpc_timeout)
+            self.local_stub.EnableLogicalDevicePort, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res)
 
     @inlineCallbacks
@@ -183,14 +193,16 @@
             port_id=port_id
         )
         res = yield threads.deferToThread(
-            self.local_stub.DisableLogicalDevicePort, req, timeout=self.grpc_timeout)
+            self.local_stub.DisableLogicalDevicePort, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res)
 
     @inlineCallbacks
     def get_device_info(self, device_id):
         req = ID(id=device_id)
         res = yield threads.deferToThread(
-            self.local_stub.GetLogicalDevice, req, timeout=self.grpc_timeout)
+            self.local_stub.GetLogicalDevice, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res)
 
     @inlineCallbacks
@@ -200,7 +212,8 @@
             flow_mod=flow_mod
         )
         res = yield threads.deferToThread(
-            self.local_stub.UpdateLogicalDeviceFlowTable, req, timeout=self.grpc_timeout)
+            self.local_stub.UpdateLogicalDeviceFlowTable, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res)
 
     @inlineCallbacks
@@ -210,38 +223,55 @@
             group_mod=group_mod
         )
         res = yield threads.deferToThread(
-            self.local_stub.UpdateLogicalDeviceFlowGroupTable, req, timeout=self.grpc_timeout)
+            self.local_stub.UpdateLogicalDeviceFlowGroupTable, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res)
 
     @inlineCallbacks
     def list_flows(self, device_id):
         req = ID(id=device_id)
         res = yield threads.deferToThread(
-            self.local_stub.ListLogicalDeviceFlows, req, timeout=self.grpc_timeout)
+            self.local_stub.ListLogicalDeviceFlows, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res.items)
 
     @inlineCallbacks
     def list_groups(self, device_id):
         req = ID(id=device_id)
         res = yield threads.deferToThread(
-            self.local_stub.ListLogicalDeviceFlowGroups, req, timeout=self.grpc_timeout)
+            self.local_stub.ListLogicalDeviceFlowGroups, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res.items)
 
     @inlineCallbacks
     def list_ports(self, device_id):
         req = ID(id=device_id)
         res = yield threads.deferToThread(
-            self.local_stub.ListLogicalDevicePorts, req, timeout=self.grpc_timeout)
+            self.local_stub.ListLogicalDevicePorts, req, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id),))
         returnValue(res.items)
 
     @inlineCallbacks
     def list_logical_devices(self):
         res = yield threads.deferToThread(
-            self.local_stub.ListLogicalDevices, empty_pb2.Empty(), timeout=self.grpc_timeout)
+            self.local_stub.ListLogicalDevices, empty_pb2.Empty(), timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id), ))
         returnValue(res.items)
 
     @inlineCallbacks
     def subscribe(self, subscriber):
-        res = yield threads.deferToThread(
-            self.local_stub.Subscribe, subscriber, timeout=self.grpc_timeout)
+        res, call = yield threads.deferToThread(
+            self.local_stub.Subscribe.with_call, subscriber, timeout=self.grpc_timeout,
+            metadata=((self.CORE_GROUP_ID, self.core_group_id), ))
+        returned_metadata = call.initial_metadata()
+
+        # Update the core_group_id if present in the returned metadata
+        if returned_metadata is None:
+            log.debug('header-metadata-missing')
+        else:
+            log.debug('metadata-returned', metadata=returned_metadata)
+            for pair in returned_metadata:
+                if pair[0] == self.CORE_GROUP_ID:
+                    self.core_group_id = pair[1]
+                    log.debug('received-core-group-id', vcore_group=self.core_group_id)
         returnValue(res)