DDOS - how to escape from it?

Yesterday for the first time we encountered a DDOS attack.
There are about 100 small projects on the server (Customers, well, a couple of their projects)
One ip on all, dedicated server (i.e. fully at our disposal).
The nightmare lasted 6 hours, spamming pings to our ip with IPs like xxx.xxx.xxx.0
and to whom exactly did the ddos ​​intend not to calculate ...
The hoster simply limited the channel to our server, so would all the counter measures.

Today it all started on a new one. How to fight, what to do no one knows ...
Sit, wait ...
Maybe there are protection options, tell me who can.
Thank.