// Module included in the following assemblies:
// * installing_tnf/operating-degraded-two-node-fencing-cluster.adoc

:_mod-docs-content-type: PROCEDURE
[id="resolving-a-failed-node-not-rejoining-after-power-on_{context}"]
= Resolving a failed node not rejoining after power-on

[role="_abstract"]
If the failed node does not rejoin the cluster after being powered on, verify Corosync connectivity and service health.

.Procedure

. Verify Corosync and cluster service status on the returning node by running the following command:
+
[source,terminal]
----
$ oc debug node/<returning-node> -- chroot /host bash -c '\
  corosync-cfgtool -s\
  systemctl status corosync pacemaker pcsd
'
----

. Verify network connectivity between both nodes.
+
* For a  Cluster Network (Corosync), ping an adjacent node to check the peer node on the cluster network by running the following command:
+
[source,terminal]
----
$ ping -c 3 <peer_node_ip>
----
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* For a Management or BMC Network (Fencing Path), run the following command:
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[source,terminal]
----
$ ping -c 3
----
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The output is similar to the following example:
+ 
[source,terminal]
----
HTTP_CODE: 401
TIME_TOTAL: 0.224628s
TIME_CONNECT: 0.000322s
----
+
[NOTE]
====
The `HTTP 401` code is expected because the curl command does not pass credentials (no --user Administrator:password). It confirms the Redfish API is listening and rejecting unauthenticated requests.

TIME_CONNECT value is approximately 0.322ms which shows the fast connectivity.
====
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* For an Application Network (OpenShift/etcd), perform the following tasks:
+
** Check API server health on the local node by running the following command:
+ 
[source,terminal]
----
$ curl -sk https://localhost:6443/healthz
----
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** Check API server health on the peer node by running the following command:
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[source,terminal]
----
$ curl -sk https://<peer-node-ip>:6443/healthz
----
+
** List etcd cluster members by running the following command:
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[source,terminal]
----
$ podman exec etcd etcdctl member list --write-out=table
----
+
** Check etcd endpoint health across the cluster by running the following command:
+
[source,terminal]
----
$ podman exec etcd etcdctl endpoint health --cluster
----
