Cannot connect to a server via ssh after the sudo ip addr flash eth0 execution

I tried to solve some problem and executed the "sudo ip addr flush eth0" command on RedHat. After that connection to the server on which this command was executed does not work. The server is located far from me. How can I resolve this issue? Does administrator should tune network? Or there is a more simple way to solve the problem?

Your command removed all addresses on the server's eth0 interface.

If that was the only way to access the server it's not reachable anymore.

Hopefully there is an out of band remote console access available (VMware remote console, Dell iDRAC, HP iLO, etc.), which is especially useful when the network configuration is broken.

Even a method to trigger a remote reboot to the server would revert it to its standard network configuration (if files weren't tampered with). But as you were already trying to correct a problem, I can't tell if this would improve the situation or worsen it.