diff --git a/neutron/agent/l3/config.py b/neutron/agent/l3/config.py
index db734168a21..49e5dd51614 100644
--- a/neutron/agent/l3/config.py
+++ b/neutron/agent/l3/config.py
@@ -16,9 +16,14 @@
 
 from oslo_config import cfg
 
+from neutron.common import constants
+
 
 OPTS = [
-    cfg.StrOpt('agent_mode', default='legacy',
+    cfg.StrOpt('agent_mode', default=constants.L3_AGENT_MODE_LEGACY,
+               choices=(constants.L3_AGENT_MODE_DVR,
+                        constants.L3_AGENT_MODE_DVR_SNAT,
+                        constants.L3_AGENT_MODE_LEGACY),
                help=_("The working mode for the agent. Allowed modes are: "
                       "'legacy' - this preserves the existing behavior "
                       "where the L3 agent is deployed on a centralized "
diff --git a/neutron/agent/l3/ha.py b/neutron/agent/l3/ha.py
index 4a7fe3e47cf..dc34b93d18e 100644
--- a/neutron/agent/l3/ha.py
+++ b/neutron/agent/l3/ha.py
@@ -17,6 +17,7 @@ import os
 
 from oslo_config import cfg
 
+from neutron.agent.linux import keepalived
 from neutron.common import constants as l3_constants
 from neutron.i18n import _LE
 from neutron.openstack.common import log as logging
@@ -33,7 +34,8 @@ OPTS = [
                       'config files')),
     cfg.StrOpt('ha_vrrp_auth_type',
                default='PASS',
-               help=_('VRRP authentication type AH/PASS')),
+               choices=keepalived.VALID_AUTH_TYPES,
+               help=_('VRRP authentication type')),
     cfg.StrOpt('ha_vrrp_auth_password',
                help=_('VRRP authentication password'),
                secret=True),
diff --git a/neutron/plugins/mlnx/agent/config.py b/neutron/plugins/mlnx/agent/config.py
index 39c618ca639..341553834ec 100644
--- a/neutron/plugins/mlnx/agent/config.py
+++ b/neutron/plugins/mlnx/agent/config.py
@@ -26,8 +26,8 @@ eswitch_opts = [
                 help=_("List of <physical_network>:<physical_interface>")),
     cfg.StrOpt('vnic_type',
                default=constants.VIF_TYPE_DIRECT,
-               help=_("Type of VM network interface: mlnx_direct or "
-                      "hostdev")),
+               choices=(constants.VIF_TYPE_DIRECT, constants.VIF_TYPE_HOSTDEV),
+               help=_("Type of VM network interface")),
     cfg.StrOpt('daemon_endpoint',
                default='tcp://127.0.0.1:60001',
                help=_('eswitch daemon end point')),
diff --git a/neutron/plugins/vmware/common/config.py b/neutron/plugins/vmware/common/config.py
index 281bac55731..89b5eeb7181 100644
--- a/neutron/plugins/vmware/common/config.py
+++ b/neutron/plugins/vmware/common/config.py
@@ -61,9 +61,9 @@ base_opts = [
                       "does not support namespaces otherwise access_network "
                       "should be used.")),
     cfg.StrOpt('default_transport_type', default='stt',
+               choices=('stt', 'gre', 'bridge', 'ipsec_gre', 'ipsec_stt'),
                deprecated_group='NVP',
-               help=_("The default network tranport type to use (stt, gre, "
-                      "bridge, ipsec_gre, or ipsec_stt)")),
+               help=_("The default network transport type to use")),
     cfg.StrOpt('agent_mode', default=AgentModes.AGENT,
                deprecated_group='NVP',
                help=_("The mode used to implement DHCP/metadata services.")),