How to make connection monitoring to VPS?

Question

Monitoring

Good day.
There was a problem, an attack went on the VPS, we don’t understand what the problem is, because the hoster said that everything is fine with the VPS, there are no problems and there are no visibility of attacks. Subdomains (which we know about, as it is AC) work. But the main page of the site, the main domain, does not work.
We checked the availability of the site here - https://2ip.ru/site-availability/, the site was accessible from all countries, the HTTP code was 301.
I would like to know what it could be, and the main question is whether it is possible to somehow monitor in online mode, from which IPs a connection is made to the server / site in order to understand which IP to block during an attack. Or what to do and how to be? It’s abstruse, please don’t answer, I don’t rummage in VPS, everything was set up for a fee.

Answer 1

The most banal thing is to look at the access log cat /var/log/{ваш веб сервер}/access.logof your web server, and you will take away both the IP and the user-agent and where the requests are made.
You can take the data from there with a script
Or, in general, it’s better to put fail2ban on the Internet with full information on it and configure it to ban all bot-nets