This article explains how to gather information about your system and possible sources of errors occurring when your Dedicated Server fails.


If you have network problems with your server, IONOS customer service may ask you to run the MTR diagnostic tool to collect further information. MTR (My Traceroute) combines the tools ping and traceroute. For instructions on installing MTR and running tests, see the following article:

Using MTR for Network Diagnostics

When troubleshooting network latency issues, we first ask you to check your server for configuration issues, updates, plugins, custom program code, and other settings. Instructions for collecting the information that IONOS customer service needs for troubleshooting can be found in the following article:

Required Information for Network Tickets

Further information on how to identify a defective hard disk in a Dedicated Server with software or hardware RAID, and how to prepare the server to replace the defective disk, can be found here:

Diagnose and Replace a Defective Hard Drive (Linux Dedicated Server with Software RAID)

Diagnose and Replace a Defective Hard Drive (Linux Dedicated Server with Hardware Raid)

Diagnose and Replace a Defective Hard Drive (Windows Dedicated Server with Software RAID)

Diagnose and Replace a Defective Hard Drive (Windows Dedicated Server with Hardware Raid)

If your Dedicated Server is no longer accessible, please first try to eliminate possible sources of error step by step to identify and solve the cause as quickly as possible. Proceed as follows:

Restart the Server and Check the SSH or Remote Desktop Connection


Depending on the operating system and configuration of the server, this process can take up to 10 minutes.

  • Check whether you can connect to the server using SSH (Linux) or Remote Desktop (Microsoft Windows Server).


If you receive a message that the password is incorrect, check the credentials and reset the root password (Linux) or the administrator password (Microsoft Windows) if necessary.

Check the Log Files

If you can establish a connection to your server, check the log files of your server. When troubleshooting, consider updates and configuration changes that may have been made recently.

If you cannot connect to your server, continue with the next step.

Check the Firewall Policy and Firewall Rules

  • In the Cloud Panel, check which firewall policy is assigned to the server in the Infrastructure > Server section.

  • In the Network > Firewall Policy section, check if the required ports have been opened in the assigned firewall policy. If necessary, assign the correct firewall policy to the server or create the necessary rules for the port  releases in the assigned firewall policy, such as port 22 for SSH or port 3389 for RDP.

  • Try again to connect to the server via SSH (Linux) or Remote Desktop (Microsoft Windows Server).

Perform a Port Scan

If you cannot connect to the server after checking and possibly adjusting the firewall policy in the Cloud Panel, perform a port scan. To do this on your local computer, enter the appropriate command in the Terminal (Linux) or Power Shell (Microsoft Windows):




[root@localhost ~]# nc -v 22

Microsoft Windows



Test NetConnection -Port 2


If the required ports are still blocked after the firewall policies have been checked and adjusted, you will need to check the firewall settings in your operating system.

Boot into the rescue system and check the server configuration

If you cannot connect to the server, boot the server into the Linux or Windows rescue system and then log on to the server using the VNC console. Then check the firewall configuration and your network settings.

The most important commands you need to check the network configuration and firewall configuration are listed in the following article:

Checking the firewall configuration and the network settings (Linux)

Further Information


If your server cannot boot into the rescue system or you are having problems with troubleshooting, please contact the support.