Can I use hashlimit and connlimit at same time?

Hello,

I'm seeking help to prevent my server from some DoS attacks, I'm linux novice and during search I found to many things like connlimit, hashlimit, hitcount.

I wonder do I have to use only 1 module or I can still use all the modules connlimit, haslimit and hitcount at the same time?

I hope to find some help as I'm really confusing

Sure, but t can be a bit of an art, so lots of googling and reading are called for:

Iptables Limits Connections Per IP

Using hashlimit in iptables | Server Buddies

How to Block SSH Brute Force Attacks - rackAID

Escalating Consequences with IPTables � That's Geeky