====== Proxmox: Fixing Host Key Verification Failed Error ======

=== Issue: ===
 Hosts in a Proxmox cluster are unable to access each other due to a "Host key verification failed" error.

=== Solution: ===
To resolve this issue, you need to update the SSH host keys for each node in the cluster. This can be achieved by running the following command on every node for every other node in the cluster:

<code>
ssh -o 'HostKeyAlias=NODENAME' root@NODEIP
</code>

Replace NODENAME with the actual hostname of the node and NODEIP with the IP address of the node.

Important: Run this command for every node in the cluster. 

=== Example: ===
For a cluster with three nodes: node1, node2, and node3 with IP addresses 192.168.1.1, 192.168.1.2, and 192.168.1.3 respectively, execute the following commands:

<code>
# On node1
ssh -o 'HostKeyAlias=node2' root@192.168.1.2
ssh -o 'HostKeyAlias=node3' root@192.168.1.3

# On node2
ssh -o 'HostKeyAlias=node1' root@192.168.1.1
ssh -o 'HostKeyAlias=node3' root@192.168.1.3

# On node3
ssh -o 'HostKeyAlias=node1' root@192.168.1.1
ssh -o 'HostKeyAlias=node2' root@192.168.1.2
</code>