Unable to connect to 192.168.10.14:22 over ssh: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain

1

Hi fellows,
I am currently try to learn K3S what is very confusing to me.
So I installed a single node cluster on proxmox (1Master 4 agents all debian VM)

when I tried to install another node using k3sup like this

sudo k3sup join --ip 192.168.10.16 --user root --server-user root --server-ip 192.168.10.14 --server

I get: unable to connect to 192.168.10.14:22 over ssh: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain

I set PermitRootLogin in sshd_conf on yes also TCP-Forwarding yes without success. What else could be the reason for that error?

Any help is appreciated

Uli

2

@uek67 Hi, I normally use ssh keys… So, on the system your running k3sup from (and you shouldn’t need sudo), the server 192.168.10.14? Can you ssh (as your user) to 192.168.10.16?

3

Hi malcomlewis,
sorry for my delayed answer I did the following I setup a new k3s-master node reinstalled all 4 agents with the new servers token and tried to conncet via ssh from the master-node to all agent-nodes (ssh-publickey) what worked fine and from any agent-node to the master-node what also worked (password)
master-node has 192.168.10.59 the agent-nodes

  • 192.168.10.14
  • 192.168.10.61
  • 192.168.10.63
  • 192.168.10.65

now kubectl get nodes only shows the master but no worker node and k3sup fails with the same error as before

k3sup install --ip 192.168.10.14 --user=root --cluster
Running: k3sup install
2024/08/13 13:59:57 192.168.10.14
Public IP: 192.168.10.14
Error: unable to connect to 192.168.10.14:22 over ssh: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain
uli@K3s-master-node-1:~$ k3sup install --ip 192.168.10.59 --user=root --cluster
Running: k3sup install
2024/08/13 14:00:08 192.168.10.59
Public IP: 192.168.10.59
Error: unable to connect to 192.168.10.59:22 over ssh: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain
uli@K3s-master-node-1:~$ k3sup install --ip 192.168.10.63 --user=root --cluster
Running: k3sup install
2024/08/13 14:00:27 192.168.10.63
Public IP: 192.168.10.63
Error: unable to connect to 192.168.10.63:22 over ssh: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain

I currently have no more idea how to fix that.

Maybee you

Many Thanks in advance,

Uli

4

@uek67 Hi, either firewall issue, or on the workers sshd configuration, I’m on openSUSE and use;

cat /etc/ssh/sshd_config.d/01-ssd.conf

PermitRootLogin yes
PasswordAuthentication yes
5

Hi malcomlewis,

I am on a debian 12 machine and my sshd_config
looks like

Authentication:

#LoginGraceTime 2m
PermitRootLogin yes
PasswordAuthentication yes
StrictModes yes
MaxAuthTries 6
MaxSessions 10

further TCO forwarding is activated and public-key-authentication instead of PasswordAuthentication I also tried no success.

Regards,

Uli

6

@uek67 and sysctl is forwarding ipv4 net.ipv4.ip_forward = 1

So from your master if you ssh -v <worker_ip> you can connect ok?

7

Hi malcomlewis,

right routing ipv4 is activates ssh -v user@ip-worker-node works fine reverse also.

Thanks in advance for your help.

Uli

8

with your setting ( using sudo and user=root), are you able to do passwordless ssh as root to root@master-node from the worker-nodes?

9

Problem solved it was the sshd_config Authentication section

On the Machine you want to install k3s via k3sup install --ip --user
root --cluster you must configure passwordless root Authentication like this:

Authentication
PasswordAuthentication no
PermitRootLogin without-password


then   systemctl restart ssh.service

On the Master node from where you rum k3sup install as root user (important) leave the sshd_config untouched!!!

Before editing the sshd_config file on the new master-node you have to ssh-copy your rsa ssh_key (ed25519 does not work) to the new Master node like eg ssh-copy-id root@ip-address
Thanks so much for all your help.

Uli

1 Like