Is this a fully managed server? If not, then I recommend you hire a server admin that can harden and manage the VPS for you. Server hardening is a very broad subject and can NOT all be covered with a simple forum reply.
There are many tutorials and guides on the web you can Google and use to start learning yourself, if that's your intention. :thumbup:
The protection is best placed either on the Host Node where the guest OS is running, or if purely network based, at the perimeter of the network on which the Host Node is sitting.
You're probably better off looking for a fully managed provider to assist you. There are so many types of protections / configurations / tweaks all for different things.
No amount of replies to this thread will help. Good luck though!
The measures depends on what type of attack we are dealing with. Spamming, spoofing, DDOS.
1. DDOS: Firewall does a great deal to tackle this.
2. Spamming and spoofing: Mail server hardening has to be done.
What is actually important to this topic is how to increase the security of your VPS. This might be achieved by many steps.
1. The first thing that you should do is to disable all unnecessary scripts that are being used.
2. Also there is a necessity to secure your VPS by installing some kind of programs. RootKit Hunter or CHKRootKit would work just fine in this case.
3. Another suggestion would be securing configuration file (.conf) systems like host, sysctl and nsswitch
4. Furthermore, consider stopping the system resource intensive tools. One of them could be ClamAV or MRTH on the system.
Every one here will suggest you many things to try but trust me when you starts get attack it won't stop until you take a proper stand.
Move to the provider who actually offer you services again attacks. Don't go to a site who has high PR or they do high ADV on net - most of time they fails and they put more money to wiped out it.
don't go to anyone who charge you very small or cheap - because you know small thing always came into small packages if you want big - end up paying high cost, and cheap always be the cheap quality because no one stupid.
Talk with the provider before investing.