Problem with SSH connection on Ubuntu 24.04 operating system

Google Cloud Cloud Foundations & Onboarding
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I am having trouble accessing servers created on GCP with the Ubuntu 24.04 operating system. I normally access them through the GCP SSH connection, but I cannot make the SSH connection through Putty on the same network. I am using a Windows server on the same network to perform Putty (SSH), it shows the error “No Supported authentication methods available (server sent: publickey)”. Firewall rules are released, I can perform telnet on port 22 normally. The sshd_config file settings were performed the same as the Ubuntu 18.04 servers. The problem persists… 8 servers were created and all have the same problem.

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Hello @mmoraes ,Welcome on Google Cloud Community.

This errors indicates that the server is configured to use public key authentication but PuTTy is not configured to use this key at all ( or key taken from Putty is wrong)

  1. Did you’ve tried maybe not using Putty but for example Moba and connect to those VMs via Moba ssh ?: https://mobaxterm.mobatek.net/

  2. Do you have access to those VMs ? Maybe via browser ssh ?

  3. You can check your Putty key following those steps:

  4. Generate a .ppk File for PuTTY: If you have a private key in OpenSSH format, you need to convert it to PuTTY’s .ppk format using PuTTYgen.

    • Open PuTTYgen.
    • Load your existing private key (e.g., id_rsa).
    • Save the private key as a .ppk file.

  5. Configure PuTTY to Use the .ppk File:

    • Open PuTTY.
    • Navigate to Connection > SSH > Auth.
    • Browse and select your .ppk file.

  6. Ensure Correct Username:

    • In PuTTY, under Session, ensure you are using the correct username for the server. The default username for GCP Ubuntu instances is usually ubuntu.

–
cheers,
DamianS
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