diff --git a/doc/source/user/index.rst b/doc/source/user/index.rst
index 7a79e7a111..f652ae8b38 100644
--- a/doc/source/user/index.rst
+++ b/doc/source/user/index.rst
@@ -1180,7 +1180,7 @@ _`container_infra_prefix`
 
   Images that must be mirrored:
 
-  * docker.io/coredns/coredns:1.3.1
+  * docker.io/coredns/coredns
   * docker.io/openstackmagnum/etcd
   * docker.io/openstackmagnum/flannel
   * docker.io/openstackmagnum/kubernetes-apiserver
@@ -1268,7 +1268,9 @@ _`coredns_tag`
   based on its container tag
   <https://hub.docker.com/r/coredns/coredns/tags/>`_.
   If unset, the current Magnum version's a default etcd version.
-  For stein, 1.3.1
+  Stein Default: 1.3.1
+  Train Default: 1.3.1
+  Ussuri Default: 1.6.6
 
 _`flannel_tag`
   This label allows users to select `a specific flannel version,
diff --git a/magnum/drivers/common/templates/kubernetes/fragments/core-dns-service.sh b/magnum/drivers/common/templates/kubernetes/fragments/core-dns-service.sh
index bf581350b6..3d961f7c97 100644
--- a/magnum/drivers/common/templates/kubernetes/fragments/core-dns-service.sh
+++ b/magnum/drivers/common/templates/kubernetes/fragments/core-dns-service.sh
@@ -110,8 +110,14 @@ spec:
       priorityClassName: system-cluster-critical
       serviceAccountName: coredns
       tolerations:
-        - key: "CriticalAddonsOnly"
-          operator: "Exists"
+        # Make sure the pod can be scheduled on master kubelet.
+        - effect: NoSchedule
+          operator: Exists
+        # Mark the pod as a critical add-on for rescheduling.
+        - key: CriticalAddonsOnly
+          operator: Exists
+        - effect: NoExecute
+          operator: Exists
       nodeSelector:
         beta.kubernetes.io/os: linux
       containers:
diff --git a/magnum/drivers/k8s_fedora_coreos_v1/templates/kubecluster.yaml b/magnum/drivers/k8s_fedora_coreos_v1/templates/kubecluster.yaml
index 42d50f0190..9aecf1f303 100644
--- a/magnum/drivers/k8s_fedora_coreos_v1/templates/kubecluster.yaml
+++ b/magnum/drivers/k8s_fedora_coreos_v1/templates/kubecluster.yaml
@@ -474,7 +474,7 @@ parameters:
   coredns_tag:
     type: string
     description: tag for coredns
-    default: 1.3.1
+    default: 1.6.6
 
   flannel_tag:
     type: string
@@ -938,6 +938,9 @@ resources:
         - protocol: tcp
           port_range_min: 22
           port_range_max: 22
+        - protocol: tcp
+          port_range_min: 53
+          port_range_max: 53
         - protocol: tcp
           port_range_min: 7080
           port_range_max: 7080
diff --git a/releasenotes/notes/upgrade-coredns-25f3879c3a658309.yaml b/releasenotes/notes/upgrade-coredns-25f3879c3a658309.yaml
new file mode 100644
index 0000000000..ee0cf24763
--- /dev/null
+++ b/releasenotes/notes/upgrade-coredns-25f3879c3a658309.yaml
@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    The default CoreDNS version has been upgraded to 1.6.6 and now
+    it can be schedule to master nodes.