diff --git a/common/utils/id_generation.py b/common/utils/id_generation.py
index 59535b8..bb2e144 100644
--- a/common/utils/id_generation.py
+++ b/common/utils/id_generation.py
@@ -35,16 +35,17 @@
 def create_cluster_logical_device_ids(core_id, switch_id):
     """
     Creates a logical device id and an OpenFlow datapath id that is unique 
-    across the Voltha cluster. Both ids represents a 64 bits integer where 
-    the lower 48 bits represents the switch id and the upper 16 bits  
-    represents the core id.  
+    across the Voltha cluster.
+    The returned ids represents a 64 bits integer where the lower 48 bits is
+    the switch id and the upper 16 bits is the core id.
     :param core_id: string
+    :param switch_id:int
     :return: cluster logical device id and OpenFlow datapath id
     """
     switch_id = format(switch_id, '012x')
-    id = '{}{}'.format(format(int(core_id), '04x'), switch_id)
-    hex_int = int(id, 16)
-    return id, hex_int
+    core_in_hex=format(int(core_id, 16), '04x')
+    id = '{}{}'.format(core_in_hex[-4:], switch_id[-12:])
+    return id, int(id, 16)
 
 def is_broadcast_core_id(id):
     assert id and len(id) == 16
diff --git a/docker/config/netcfg.json b/docker/config/netcfg.json
index 245c263..244caec 100644
--- a/docker/config/netcfg.json
+++ b/docker/config/netcfg.json
@@ -31,7 +31,7 @@
     }
   },
   "devices": {
-    "of:0001000000000001": {
+    "of:0001aabbccddeeff": {
       "basic": {
         "driver": "pmc-olt"
       },
diff --git a/voltha/adapters/ponsim_olt/ponsim_olt.py b/voltha/adapters/ponsim_olt/ponsim_olt.py
index d7a75eb..bb5b533 100644
--- a/voltha/adapters/ponsim_olt/ponsim_olt.py
+++ b/voltha/adapters/ponsim_olt/ponsim_olt.py
@@ -432,7 +432,8 @@
         ))
 
         ld = LogicalDevice(
-            # not setting id and datapth_id will let the adapter agent pick id
+            # not setting id and datapath_id.  Adapter agent will pick the id
+            # and will pick the datapath_id is it is not provided
             desc=ofp_desc(
                 mfr_desc='cord porject',
                 hw_desc='simualted pon',
@@ -452,7 +453,9 @@
             ),
             root_device_id=device.id
         )
-        ld_initialized = self.adapter_agent.create_logical_device(ld)
+        mac_address = "AA:BB:CC:DD:EE:FF"
+        ld_initialized = self.adapter_agent.create_logical_device(ld,
+                                                                  dpid=mac_address)
         cap = OFPPF_1GB_FD | OFPPF_FIBER
         self.ofp_port_no = info.nni_port
         self.adapter_agent.add_logical_port(ld_initialized.id, LogicalPort(
@@ -751,7 +754,9 @@
             ),
             root_device_id=device.id
         )
-        ld_initialized = self.adapter_agent.create_logical_device(ld)
+        mac_address = "AA:BB:CC:DD:EE:FF"
+        ld_initialized = self.adapter_agent.create_logical_device(ld,
+                                                                  dpid=mac_address)
         cap = OFPPF_1GB_FD | OFPPF_FIBER
         self.adapter_agent.add_logical_port(ld_initialized.id, LogicalPort(
             id='nni',
diff --git a/voltha/core/adapter_agent.py b/voltha/core/adapter_agent.py
index 2f73505..5c2327d 100644
--- a/voltha/core/adapter_agent.py
+++ b/voltha/core/adapter_agent.py
@@ -40,6 +40,12 @@
     LogicalPort, AdminState, OperStatus, AlarmFilterRuleKey
 from voltha.registry import registry
 from common.utils.id_generation import create_cluster_device_id
+import re
+
+
+class MacAddressError(BaseException):
+    def __init__(self, error):
+        self.error = error
 
 @implementer(IAdapterAgent)
 class AdapterAgent(object):
@@ -496,17 +502,36 @@
         self._make_up_to_date('/devices/{}/ports'.format(device_id),
                               port.port_no, port)
 
-    def _find_first_available_id(self):
+    def _find_first_available_id(self, dpid=None):
+
+        def _is_valid_mac_address(dpid):
+            return re.match("[0-9a-f]{2}([-:])[0-9a-f]{2}(\\1[0-9a-f]{2}){4}$",
+                     dpid)
+
+        # If a dpid is provided then validate whether it is a MAC address
+        switch_id = 1
+        if dpid:
+            dpid = dpid.lower()
+            if not _is_valid_mac_address(dpid):
+                raise MacAddressError('Invalid-mac-address-format')
+            switch_id = int(dpid.replace(':', ''), 16)
+
         logical_devices = self.root_proxy.get('/logical_devices')
         existing_ids = set(ld.id for ld in logical_devices)
         existing_datapath_ids = set(ld.datapath_id for ld in logical_devices)
         core_id = registry('core').core_store_id
-        i = 1
+
         while True:
-            ld_id, dp_id = create_cluster_logical_device_ids(core_id, i)
-            if dp_id not in existing_datapath_ids and ld_id not in existing_ids:
+            ld_id, dp_id = create_cluster_logical_device_ids(core_id, switch_id)
+            existing_ids = dp_id in existing_datapath_ids or ld_id in \
+                                                            existing_ids
+            if not existing_ids:
                 return ld_id, dp_id
-            i += 1
+            else:
+                if dpid:
+                    raise MacAddressError('Already-registered-mac-address')
+                else:
+                    switch_id += 1
 
     def get_logical_device(self, logical_device_id):
         return self.root_proxy.get('/logical_devices/{}'.format(
@@ -516,11 +541,18 @@
         return self.root_proxy.get('/logical_devices/{}/ports/{}'.format(
             logical_device_id, port_id))
 
-    def create_logical_device(self, logical_device):
+    def create_logical_device(self, logical_device, dpid=None):
+        """
+        Allow the adapters to provide their own datapath id.  This must
+        be the OLT MAC address.
+        :param logical_device:
+        :param dpid: OLT MAC address
+        :return: updated logical device
+        """
         assert isinstance(logical_device, LogicalDevice)
 
         if not logical_device.id:
-            ld_id, dp_id = self._find_first_available_id()
+            ld_id, dp_id = self._find_first_available_id(dpid)
             logical_device.id = ld_id
             logical_device.datapath_id = dp_id