The cluster is not assembled

[Maksimus]

The host on which the cluster is enabled is behind NAT (Mikrotik)
there is nothing on the second connected one, it looks directly at the Internet.
All ports were opened on the Mikrotik.
Hots are assembled, but on the connected one in the cluster, a red cross is lit and the error
hostname lookup 'pvecwn' failed - failed to get address info for: pvecwn: Name or service not known (500)
There is no way to remove nat.

 

[esi_y]

The host on which the cluster is enabled is behind NAT (Mikrotik)
there is nothing on the second connected one, it looks directly at the Internet.
All ports were opened on the Mikrotik.
Hots are assembled, but on the connected one in the cluster, a red cross is lit and the error
hostname lookup 'pvecwn' failed - failed to get address info for: pvecwn: Name or service not known (500)
There is no way to remove nat.

You may just really need to refresh your browser (or clear cache), but the part with NAT is a bigger concern, how in that configuration do you plan to keep low latencies required [1]? If it works with 2 nodes it will fall apart with 3rd...

[1] https://pve.proxmox.com/wiki/Cluster_Manager#_cluster_network

 

[Maksimus]

Delays are a separate issue, now the delays are 50-60 ms. We are deliberately taking this step. The question is how to interpret this error.
The browser is the latest version

 

[esi_y]

Delays are a separate issue, now the delays are 50-60 ms. We are deliberately taking this step. The question is how to interpret this error.
The browser is the latest version

Just a guess ... /etc/hosts containing the "wrong" address.

 

[Maksimus]

Found another host, without NAT we assembled a cluster but the second (added) host was added with a cross and in the file on the first host /etc/pve/priv/authorized_keys there is no key to the newly added host. Ping between hosts is 40ms

 

[esi_y]

Found another host, without NAT we assembled a cluster but the second (added) host was added with a cross and in the file on the first host /etc/pve/priv/authorized_keys there is no key to the newly added host. Ping between hosts is 40ms

If I understood you well, you have issues with GUI (not) reflecting what you think you had been doing even in non-NAT environment. First of all, 40ms is too much for having a reliable cluster in PVE. With GUI, you are also really half-blind, because sometimes a refresh (or clearing cookies) suddenly shows you what really happened.

If you feel comfortable with SSH, just get in and you can check (on each node separately) if you got a cluster with: pvecm status.

To troubleshoot what's not working you would need to start looking at journalctl -u corosync

The clusters in PVE just do not work well in high latency environments, I am not sure what's he purpose, but e.g. High Availability will be out of question. You may read more on this here: https://forum.proxmox.com/threads/high-latency-clusters.141098/