reighto
03-08-2016, 13:08

- VPN adds a lot of latency as any connection towards your server would first have to go through the VPN server
- PureVPN is consumer targeted VPN service and not suitable for dedicated servers due zero SLA promises (Meaning it can go down anytime).
- PureVPN is is known to be slow
- They have all ports closed and you will be sharing a given ip-address with other end users.
- Its just retarded idea when you already have a working anti-ddos and a dedicated server.
- They are able to see all data flowing to your server.
- And finally the guy you are replying is a known spammer who puts that message in every thread and finally gives you some affiliation link which makes him money when he recruits a new customer. He will just say "yes, yes" to any question you ask.
As said before, it's likely application level (L7) attack or some sort of SYN flood (L4).
If it's application level attack, you have to fix the problem yourself in the software you are using.
If it's SYN flood, OVH anti-ddos fixes most of that for you, but you need to take steps to make sure the server recourses are not being clogged. This would include kernel hardening against syn floods ip-table rules (preferably non-tracked and PREROUTING)
This is rather good article which helped me to overcome SYN flood with E3-SAT-1 model: https://javapipe.com/iptables-ddos-protection You have a powerful CPU, you have plenty of possibilites to solve stuff using iptables when majority of the attack is blocked on network level by OVH.
Finally you can tcpdump of the attack and submit it via ticket to the support so they can tune the network for you, or better paste it so we can help you. The filesize of such tcpdump should be multiple megabytes.
Unless the attack is UDP flood (L4) on random ports 40 Gbps+ at constant rate, the included anti-ddos should easily be able to handle it. Something else is taking up your server resources during an attack. this can be badly configured iptables as well.
OVH known for the hardware and it's anti-ddos. You shouldn't need to buy any external services from other websites.