diff --git a/roles/run-tempest-26/tasks/main.yaml b/roles/run-tempest-26/tasks/main.yaml
index 7423bfb..7ad5c99 100644
--- a/roles/run-tempest-26/tasks/main.yaml
+++ b/roles/run-tempest-26/tasks/main.yaml
@@ -17,7 +17,7 @@
 
 - name: Limit max concurrency when more than 3 vcpus are available
   set_fact:
-    default_concurrency: "{{ num_cores|int // 2 }}"
+    default_concurrency: "{{ num_cores|int - 2 }}"
   when: num_cores|int > 3
 
 - name: Override target branch
diff --git a/roles/run-tempest/tasks/main.yaml b/roles/run-tempest/tasks/main.yaml
index 3fb494f..3d78557 100644
--- a/roles/run-tempest/tasks/main.yaml
+++ b/roles/run-tempest/tasks/main.yaml
@@ -17,7 +17,7 @@
 
 - name: Limit max concurrency when more than 3 vcpus are available
   set_fact:
-    default_concurrency: "{{ num_cores|int // 2 }}"
+    default_concurrency: "{{ num_cores|int - 2 }}"
   when: num_cores|int > 3
 
 - name: Override target branch
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index b4ba643..4d35bbb 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -1140,14 +1140,19 @@
                                             server=server,
                                             username=username)
 
+        # Default the directory in which to write the timestamp file to /tmp
+        # and only use the mount_path as the target directory if we mounted
+        # dev_name to mount_path.
+        target_dir = '/tmp'
         if dev_name is not None:
             ssh_client.make_fs(dev_name, fs=fs)
             ssh_client.exec_command('sudo mount /dev/%s %s' % (dev_name,
                                                                mount_path))
-        cmd_timestamp = 'sudo sh -c "date > %s/timestamp; sync"' % mount_path
+            target_dir = mount_path
+        cmd_timestamp = 'sudo sh -c "date > %s/timestamp; sync"' % target_dir
         ssh_client.exec_command(cmd_timestamp)
         timestamp = ssh_client.exec_command('sudo cat %s/timestamp'
-                                            % mount_path)
+                                            % target_dir)
         if dev_name is not None:
             ssh_client.exec_command('sudo umount %s' % mount_path)
         return timestamp
@@ -1172,10 +1177,15 @@
                                             server=server,
                                             username=username)
 
+        # Default the directory from which to read the timestamp file to /tmp
+        # and only use the mount_path as the target directory if we mounted
+        # dev_name to mount_path.
+        target_dir = '/tmp'
         if dev_name is not None:
             ssh_client.mount(dev_name, mount_path)
+            target_dir = mount_path
         timestamp = ssh_client.exec_command('sudo cat %s/timestamp'
-                                            % mount_path)
+                                            % target_dir)
         if dev_name is not None:
             ssh_client.exec_command('sudo umount %s' % mount_path)
         return timestamp
diff --git a/tempest/scenario/test_network_basic_ops.py b/tempest/scenario/test_network_basic_ops.py
index cbe4122..7b819e0 100644
--- a/tempest/scenario/test_network_basic_ops.py
+++ b/tempest/scenario/test_network_basic_ops.py
@@ -898,10 +898,13 @@
                                        nic=spoof_nic, should_succeed=True)
         # Set a mac address by making nic down temporary
         spoof_ip_addresses = ssh_client.get_nic_ip_addresses(spoof_nic)
-        cmd = ("sudo ip link set {nic} down;"
+        dhcp_cmd = ("sudo start-stop-daemon -K -x /sbin/dhcpcd -p "
+                    "/var/run/dhcpcd/pid -o || true")
+        cmd = ("{dhcp_cmd}; sudo ip link set {nic} down;"
                "sudo ip link set dev {nic} address {mac};"
                "sudo ip link set {nic} up;"
                "sudo ip address flush dev {nic};").format(nic=spoof_nic,
+                                                          dhcp_cmd=dhcp_cmd,
                                                           mac=spoof_mac)
         for ip_address in spoof_ip_addresses:
             cmd += (
diff --git a/zuul.d/integrated-gate.yaml b/zuul.d/integrated-gate.yaml
index 0901788..8ac0b42 100644
--- a/zuul.d/integrated-gate.yaml
+++ b/zuul.d/integrated-gate.yaml
@@ -393,12 +393,24 @@
         # Keystone policies are changed to work for both system as well as
         # for project scoped, we need to keep scope check disable for
         # keystone.
-        NOVA_ENFORCE_SCOPE: true
+        # Nova and Glance have enabled the new defaults and scope by default
+        # in devstack.
         CINDER_ENFORCE_SCOPE: true
-        GLANCE_ENFORCE_SCOPE: true
         NEUTRON_ENFORCE_SCOPE: true
         PLACEMENT_ENFORCE_SCOPE: true
 
+- job:
+    name: tempest-all-rbac-old-defaults
+    parent: tempest-all
+    description: |
+      Integration test that runs all tests on RBAC old defaults.
+      devstack_localrc:
+        # NOTE(gmann): Nova and Glance have enabled the new defaults and scope
+        # by default in devstack so we need some jobs keep testing the old
+        # defaults until they are removed from service side.
+        NOVA_ENFORCE_SCOPE: false
+        GLANCE_ENFORCE_SCOPE: false
+
 - project-template:
     name: integrated-gate-networking
     description: |
diff --git a/zuul.d/project.yaml b/zuul.d/project.yaml
index 3223a1e..894e623 100644
--- a/zuul.d/project.yaml
+++ b/zuul.d/project.yaml
@@ -157,6 +157,7 @@
             irrelevant-files: *tempest-irrelevant-files
         - tempest-all:
             irrelevant-files: *tempest-irrelevant-files
+        - tempest-all-rbac-old-defaults
         - tempest-full-parallel
         - tempest-full-zed-extra-tests
         - tempest-full-yoga-extra-tests
@@ -191,6 +192,7 @@
     periodic:
       jobs:
         - tempest-all
+        - tempest-all-rbac-old-defaults
         - tempest-full-parallel
         - tempest-full-oslo-master
         - tempest-stestr-master