diff --git a/lower-constraints.txt b/lower-constraints.txt
index 7eaa6257e7d..5b6d6d9da52 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -51,7 +51,7 @@ msgpack-python==0.4.0
 munch==2.1.0
 netaddr==0.7.18
 netifaces==0.10.4
-neutron-lib==2.3.0
+neutron-lib==2.4.0
 openstacksdk==0.31.2
 os-client-config==1.28.0
 os-ken==0.3.0
diff --git a/neutron/agent/linux/dhcp.py b/neutron/agent/linux/dhcp.py
index 15d80289a5a..011f7bfedd4 100644
--- a/neutron/agent/linux/dhcp.py
+++ b/neutron/agent/linux/dhcp.py
@@ -45,11 +45,7 @@ from neutron.ipam import utils as ipam_utils
 
 LOG = logging.getLogger(__name__)
 
-UDP = 'udp'
-TCP = 'tcp'
 DNS_PORT = 53
-DHCPV4_PORT = 67
-DHCPV6_PORT = 547
 METADATA_DEFAULT_IP = '169.254.169.254'
 METADATA_SUBNET_CIDR = '169.254.0.0/16'
 METADATA_PORT = 80
@@ -344,9 +340,13 @@ class Dnsmasq(DhcpLocalProcess):
     # on the Neutron port used for DHCP.  These are provided as a convenience
     # for users of this class.
     PORTS = {constants.IP_VERSION_4:
-             [(UDP, DNS_PORT), (TCP, DNS_PORT), (UDP, DHCPV4_PORT)],
+             [(constants.PROTO_NAME_UDP, DNS_PORT),
+              (constants.PROTO_NAME_TCP, DNS_PORT),
+              (constants.PROTO_NAME_UDP, constants.DHCP_RESPONSE_PORT)],
              constants.IP_VERSION_6:
-             [(UDP, DNS_PORT), (TCP, DNS_PORT), (UDP, DHCPV6_PORT)],
+             [(constants.PROTO_NAME_UDP, DNS_PORT),
+              (constants.PROTO_NAME_TCP, DNS_PORT),
+              (constants.PROTO_NAME_UDP, constants.DHCPV6_RESPONSE_PORT)],
              }
 
     _SUBNET_TAG_PREFIX = 'subnet-%s'
@@ -1742,7 +1742,7 @@ class DeviceManager(object):
                                                         nat=False,
                                                         namespace=namespace)
         ipv4_rule = ('-p udp -m udp --dport %d -j CHECKSUM --checksum-fill'
-                     % constants.DHCP_RESPONSE_PORT)
+                     % constants.DHCP_CLIENT_PORT)
         ipv6_rule = ('-p udp -m udp --dport %d -j CHECKSUM --checksum-fill'
                      % constants.DHCPV6_CLIENT_PORT)
         iptables_mgr.ipv4['mangle'].add_rule('POSTROUTING', ipv4_rule)
diff --git a/neutron/tests/unit/agent/dhcp/test_agent.py b/neutron/tests/unit/agent/dhcp/test_agent.py
index 6b9b982b3a4..17a94264b58 100644
--- a/neutron/tests/unit/agent/dhcp/test_agent.py
+++ b/neutron/tests/unit/agent/dhcp/test_agent.py
@@ -1860,7 +1860,7 @@ class TestDeviceManager(base.BaseTestCase):
     def test_setup_calls_fill_dhcp_udp_checksums_v4(self):
         self._test_setup_helper(False)
         rule = ('-p udp -m udp --dport %d -j CHECKSUM --checksum-fill'
-                % const.DHCP_RESPONSE_PORT)
+                % const.DHCP_CLIENT_PORT)
         expected = [mock.call.add_rule('POSTROUTING', rule)]
         self.mangle_inst_v4.assert_has_calls(expected)
 
diff --git a/requirements.txt b/requirements.txt
index 1e53423d35e..2a3f4e9e596 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,7 @@ Jinja2>=2.10 # BSD License (3 clause)
 keystonemiddleware>=4.17.0 # Apache-2.0
 netaddr>=0.7.18 # BSD
 netifaces>=0.10.4 # MIT
-neutron-lib>=2.3.0 # Apache-2.0
+neutron-lib>=2.4.0 # Apache-2.0
 python-neutronclient>=6.7.0 # Apache-2.0
 tenacity>=4.4.0 # Apache-2.0
 SQLAlchemy>=1.2.0 # MIT