[r1ch]

Most DDoS attacks are volumetric. There isn't a way to defend against this other than simply having a huge pipe, or paying someone with a huge pipe to be in front of your site.

Non-volumetric attacks like SYN or HTTP floods can be mitigated with appropriate rate limiting or firewalling.

Some providers like OVH have decent network-level mitigation in place, but you're not gonna find that on a $5 VPS where they're more than happy to null route you to protect their network.

[rmdoss]

Depending on the size of the syn flood or HTTP flood, there is no way you can handle it locally.

Some syn floods can generate millions of packets per second, which is way more than a dedicated linux server can handle.

Good video on the topic:

https://www.youtube.com/watch?v=pCVTEx1ouyk