How to stop the traffic attack to nameserver

[风河]

2011/12/10  <sthaug at nethelp.no>:
>> My name servers have got many times of traffic attack.
>> When the large bulk of traffic is delivered to nameserver, the server
>> is almost dead.
>> For example, the attacking traffic was more than 2G to a single host sometime.
>
> Are these your authoritative or your recursive name servers? These are
> different services and should run on different hosts.
>

I am running the DNS hosting service.
All the nameservers are authoritative.
Thanks.