Unable to SSH or SCP into my root server for almost 8 hours now !!

    I have been unable to SSH into my root server for 8 hours now. I also tried to use the _Connect feature in the control panel (that pops up the VNCPopUp window) but it keeps failing. (showing the Not Connected message with a connect button. I tried clicking the Click button multiple times without any luck).

    See the attached image:


    I sent netcup a Support ticket almost 6 hours ago and they are yet to answer !!


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    My server hosts a website running on Apache and MySQL (both seem to be running fine as of writing this).

    I have a script that restricts server access to only my home IP address, automatically updating the IP when it changes. As a backup, I used to access the root server via the "_Screen" button (shown in the attached image), but today it stopped working, displaying a "Not connected" error. What could be causing this issue, and how can I fix it?


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    I had same problem yesterday after an upgrade.

    Can you check if the ping works? And if so, try:
    ssh -o KexAlgorithms=curve25519-sha256 <your ip address> -p <portnumber>

    If works, log in and add in /etc/ssh/sshd.config this line:


    KexAlgorithms curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group14-sha256


    And restart sshd or machine.

    I

    Thanks for the suggestion. I tried pinging the server, but it’s not responding, so I think I’m completely locked out. The script that’s supposed to update the IP address in iptables after my ISP changed it earlier today (Saturday, May 24, 2025) might not be working, or something on the server is preventing the update. That said, this doesn’t explain why the "Screen" option in the control panel on servercontrolpanel.de is also failing—it just shows a "Not connected" error. Any ideas?

    Quote from frank_m

    First I would try the rescue system, mount die filesystem and open a port in the firewall. Afterwards, SSH should work again. It seems, the IP blocker is too strict.

    Thank you for the suggestion! Since Apache and MySQL are currently running on the server, I’m worried that booting into rescue mode might stop those services, and I’d rather avoid the risk, especially since Netcup’s support team won’t be back until Monday, May 26, 2025. I’m thinking it might be safer to wait for Netcup’s customer support to respond first before attempting the rescue option. At the very least, I’d prefer to have their support team available while I try your suggestion, in case they don’t resolve the issue on their end.