diff --git a/cinder/tests/unit/volume/drivers/netapp/dataontap/fakes.py b/cinder/tests/unit/volume/drivers/netapp/dataontap/fakes.py
index 7658aa5cbeb..950e92283ee 100644
--- a/cinder/tests/unit/volume/drivers/netapp/dataontap/fakes.py
+++ b/cinder/tests/unit/volume/drivers/netapp/dataontap/fakes.py
@@ -213,6 +213,12 @@ IGROUP1 = {
     'initiator-group-name': IGROUP1_NAME,
 }
 
+CUSTOM_IGROUP = {
+    'initiator-group-os-type': 'linux',
+    'initiator-group-type': 'fcp',
+    'initiator-group-name': 'node1',
+}
+
 ISCSI_VOLUME = {
     'name': 'fake_volume',
     'id': 'fake_id',
diff --git a/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_base.py b/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_base.py
index 06448e1a8af..a81778bc54f 100644
--- a/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_base.py
+++ b/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_base.py
@@ -400,10 +400,13 @@ class NetAppBlockStorageLibraryTestCase(test.TestCase):
         self.assertEqual(
             0, self.library._create_igroup_add_initiators.call_count)
 
+    @ddt.data([], [fake.CUSTOM_IGROUP])
     @mock.patch.object(uuid, 'uuid4', mock.Mock(return_value=fake.UUID1))
-    def test_get_or_create_igroup_none_preexisting(self):
-        """This method also tests _create_igroup_add_initiators."""
-        self.zapi_client.get_igroup_by_initiators.return_value = []
+    def test_get_or_create_igroup_none_preexisting(self, igroups):
+        """Test _create_igroup_add_initiators with not OS igroups."""
+        # We only care about the OpenStack igroups, so we must have the same
+        # result if there are no igroups and if the igroup is a custom one.
+        self.zapi_client.get_igroup_by_initiators.return_value = igroups
 
         igroup_name, os, ig_type = self.library._get_or_create_igroup(
             fake.FC_FORMATTED_INITIATORS, 'fcp', 'linux')
diff --git a/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_cmode.py b/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_cmode.py
index 75d03b4bff0..398d3d97e5c 100644
--- a/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_cmode.py
+++ b/cinder/tests/unit/volume/drivers/netapp/dataontap/test_block_cmode.py
@@ -207,12 +207,17 @@ class NetAppBlockStorageCmodeLibraryTestCase(test.TestCase):
             self.library.vserver, volume_list, [])
 
     def test_find_mapped_lun_igroup(self):
-        igroups = [fake.IGROUP1]
+        igroups = [fake.IGROUP1, fake.CUSTOM_IGROUP]
         self.zapi_client.get_igroup_by_initiators.return_value = igroups
 
-        lun_maps = [{'initiator-group': fake.IGROUP1_NAME,
-                     'lun-id': '1',
-                     'vserver': fake.VSERVER_NAME}]
+        lun_maps = [
+            {'initiator-group': fake.IGROUP1_NAME,
+             'lun-id': '1',
+             'vserver': fake.VSERVER_NAME},
+            {'initiator-group': fake.CUSTOM_IGROUP['initiator-group-name'],
+             'lun-id': '2',
+             'vserver': fake.VSERVER_NAME}
+        ]
         self.zapi_client.get_lun_map.return_value = lun_maps
 
         (igroup, lun_id) = self.library._find_mapped_lun_igroup(
@@ -253,12 +258,11 @@ class NetAppBlockStorageCmodeLibraryTestCase(test.TestCase):
         self.assertIsNone(lun_id)
 
     def test_find_mapped_lun_igroup_no_igroup_prefix(self):
-        igroups = [{'initiator-group-os-type': 'linux',
-                    'initiator-group-type': 'fcp',
-                    'initiator-group-name': 'igroup2'}]
+        igroups = [fake.CUSTOM_IGROUP]
+        expected_igroup = fake.CUSTOM_IGROUP['initiator-group-name']
         self.zapi_client.get_igroup_by_initiators.return_value = igroups
 
-        lun_maps = [{'initiator-group': 'igroup2',
+        lun_maps = [{'initiator-group': expected_igroup,
                      'lun-id': '1',
                      'vserver': fake.VSERVER_NAME}]
         self.zapi_client.get_lun_map.return_value = lun_maps
@@ -266,8 +270,8 @@ class NetAppBlockStorageCmodeLibraryTestCase(test.TestCase):
         (igroup, lun_id) = self.library._find_mapped_lun_igroup(
             fake.LUN_PATH, fake.FC_FORMATTED_INITIATORS)
 
-        self.assertIsNone(igroup)
-        self.assertIsNone(lun_id)
+        self.assertEqual(expected_igroup, igroup)
+        self.assertEqual('1', lun_id)
 
     def test_clone_lun_zero_block_count(self):
         """Test for when clone lun is not passed a block count."""
diff --git a/cinder/volume/drivers/netapp/dataontap/block_base.py b/cinder/volume/drivers/netapp/dataontap/block_base.py
index 30e3b8d25cd..3ff5fdd61f3 100644
--- a/cinder/volume/drivers/netapp/dataontap/block_base.py
+++ b/cinder/volume/drivers/netapp/dataontap/block_base.py
@@ -479,16 +479,17 @@ class NetAppBlockStorageLibrary(object):
         Creates igroup if not already present with given host os type,
         igroup type and adds initiators.
         """
+        # Backend supports different igroups with the same initiators, so
+        # instead of reusing non OpenStack igroups, we make sure we only use
+        # our own, thus being compatible with custom igroups.
         igroups = self.zapi_client.get_igroup_by_initiators(initiator_list)
-        igroup_name = None
-
-        if igroups:
-            igroup = igroups[0]
+        for igroup in igroups:
             igroup_name = igroup['initiator-group-name']
-            host_os_type = igroup['initiator-group-os-type']
-            initiator_group_type = igroup['initiator-group-type']
-
-        if not igroup_name:
+            if igroup_name.startswith(na_utils.OPENSTACK_PREFIX):
+                host_os_type = igroup['initiator-group-os-type']
+                initiator_group_type = igroup['initiator-group-type']
+                break
+        else:
             igroup_name = self._create_igroup_add_initiators(
                 initiator_group_type, host_os_type, initiator_list)
         return igroup_name, host_os_type, initiator_group_type
diff --git a/cinder/volume/drivers/netapp/dataontap/block_cmode.py b/cinder/volume/drivers/netapp/dataontap/block_cmode.py
index 4836245579f..59d5b04fea2 100644
--- a/cinder/volume/drivers/netapp/dataontap/block_cmode.py
+++ b/cinder/volume/drivers/netapp/dataontap/block_cmode.py
@@ -195,17 +195,20 @@ class NetAppBlockStorageCmodeLibrary(block_base.NetAppBlockStorageLibrary,
 
     def _find_mapped_lun_igroup(self, path, initiator_list):
         """Find an igroup for a LUN mapped to the given initiator(s)."""
-        initiator_igroups = self.zapi_client.get_igroup_by_initiators(
-            initiator_list)
-        lun_maps = self.zapi_client.get_lun_map(path)
-        if initiator_igroups and lun_maps:
-            for igroup in initiator_igroups:
-                igroup_name = igroup['initiator-group-name']
-                if igroup_name.startswith(na_utils.OPENSTACK_PREFIX):
-                    for lun_map in lun_maps:
-                        if lun_map['initiator-group'] == igroup_name:
-                            return igroup_name, lun_map['lun-id']
-        return None, None
+        igroups = [igroup['initiator-group-name'] for igroup in
+                   self.zapi_client.get_igroup_by_initiators(initiator_list)]
+        # Map igroup-name to lun-id, but only for the requested initiators.
+        lun_map = {v['initiator-group']: v['lun-id']
+                   for v in self.zapi_client.get_lun_map(path)
+                   if v['initiator-group'] in igroups}
+
+        igroup_name = lun_id = None
+        # Give preference to OpenStack igroups, just use the last one if not
+        # present to allow unmapping old mappings that used a custom igroup.
+        for igroup_name, lun_id in lun_map.items():
+            if igroup_name.startswith(na_utils.OPENSTACK_PREFIX):
+                break
+        return igroup_name, lun_id
 
     def _clone_lun(self, name, new_name, space_reserved=None,
                    qos_policy_group_name=None, src_block=0, dest_block=0,
diff --git a/releasenotes/notes/fix-netapp-custom-igroup-e049b4f3b341dd54.yaml b/releasenotes/notes/fix-netapp-custom-igroup-e049b4f3b341dd54.yaml
new file mode 100644
index 00000000000..f8f328d7616
--- /dev/null
+++ b/releasenotes/notes/fix-netapp-custom-igroup-e049b4f3b341dd54.yaml
@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fix NetApp iSCSI and FC driver issues with custom initiator groups.
+    (bug 1697490).