LS2,
EVERY host provides detection and mitigation of DoS (and DDoS) attacks. They are not based on your website, though, as they impact the data center where your host’s servers are located. The additional traffic (often with incorrectly formatted TCP/IP packets) can be easily seen and blocked upstream of your website’s server.
You are to be congratulated for asking this question, however, and should ask your host (or candidate hosts) about their DoS/DDoS mitigation for “that warm, fuzzy feeling.”
“There’s no rest for the wary” but it sure beats rebuilding a website from scratch!
Regards,
DK