convert dualstack cluster to ipv4 single stack cluster, worker drain with "  Warning  ErrorReconcilingNode  12s (x3 over 72s)      controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2"

4.13

1. setup dualstack cluster

# oc get network -o yaml
apiVersion: v1
items:
- apiVersion: config.openshift.io/v1
  kind: Network
  metadata:
    creationTimestamp: "2023-04-07T02:37:31Z"
    generation: 4
    name: cluster
    resourceVersion: "111453"
    uid: fba18f8d-4730-4e83-b7f0-3555b240ef3f
  spec:
    clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
    - cidr: fd01::/48
      hostPrefix: 64
    externalIP:
      policy: {}
    networkType: OVNKubernetes
    serviceNetwork:
    - 172.30.0.0/16
    - fd02::/112
  status:
    clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
    - cidr: fd01::/48
      hostPrefix: 64
    clusterNetworkMTU: 1400
    networkType: OVNKubernetes
    serviceNetwork:
    - 172.30.0.0/16
    - fd02::/112
kind: List
metadata:
  resourceVersion: ""



2. Convert to single stack by edit network to 

apiVersion: v1
items:
- apiVersion: config.openshift.io/v1
  kind: Network
  metadata:
    creationTimestamp: "2023-04-07T02:37:31Z"
    generation: 6
    name: cluster
    resourceVersion: "214413"
    uid: fba18f8d-4730-4e83-b7f0-3555b240ef3f
  spec:
    clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
    externalIP:
      policy: {}
    networkType: OVNKubernetes
    serviceNetwork:
    - 172.30.0.0/16
  status:
    clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
    clusterNetworkMTU: 1400
    networkType: OVNKubernetes
    serviceNetwork:
    - 172.30.0.0/16
kind: List
metadata:
  resourceVersion: ""

 3. # oc get node
NAME                            STATUS                     ROLES                  AGE   VERSION
master-0.ostest.openshift.com   Ready                      control-plane,master   9h    v1.26.2+7195e44
master-1.ostest.openshift.com   Ready                      control-plane,master   9h    v1.26.2+7195e44
master-2.ostest.openshift.com   Ready,SchedulingDisabled   control-plane,master   9h    v1.26.2+7195e44
worker-0.ostest.openshift.com   Ready                      worker                 8h    v1.26.2+7195e44
worker-1.ostest.openshift.com   Ready                      worker                 8h    v1.26.2+7195e44

4. oc describe node master-2.ostest.openshift.com

  Warning  ErrorReconcilingNode  19m (x5 over 21m)      controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  17m (x5 over 19m)      controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  15m (x5 over 17m)      controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  13m (x5 over 15m)      controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  11m (x6 over 13m)      controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  8m50s (x5 over 10m)    controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  6m28s (x5 over 8m28s)  controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  4m10s (x5 over 6m10s)  controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  2m4s (x6 over 4m4s)    controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2
  Warning  ErrorReconcilingNode  12s (x4 over 102s)     controlplane  nodeAdd: error adding node "master-2.ostest.openshift.com": failed to get expected host subnets for node master-2.ostest.openshift.com, expected 1 subnet(s) but current number of subnet(s) is 2