One of my clients wanted to secure their slave nodes with a firewall, and asked to install CSF on the servers. We setup a new slave node and installed CSF and everything was working fine. Created a new VPS, and noticed that the VPS IP Address is not responding. There was no ping to the VPS IP Address from outside. Logged into the server via console and the IP Address was up in the server. However there was no inbound and outbound network connections.

Thinking it could be a resolver problem, I switched the resolver entries to use google DNS as follows.

Save and quit the file. Tried to ping google.com again from the server and it timed out again...

I was working on my client’s solusvm admin panel that I got kicked out suddenly. I started getting the following message, whatever way I tried to access the admin control panel.

I tried various ways to gain access, but nothing worked. The following trick helped me.

I logged in to the server as root via ssh and whitelisted my IP Address.