DDOS attack Bind 9.9 - P2

I have isc.org attack."* isc.org internet *?".* It comes from my own clients that I have allowed in my ACL. the question is how to stop this attack? this causes my traffic on the interface is intense and also up my cpu percentage. that I can do to prevent it?? __

I'm having thousands of queries a domain isc.org and this increases my cpu percentage to 100%. That may be happening and how I can control this? is an attack? attachment of the log I made an update to

190.34.55.70 -> 201.224.83.242 DNS C isc.org. Internet * ? 190.33.3.27 -> 201.224.83.242 DNS C isc.org. Internet * ? 190.32.57.243 -> 201.224.83.242 DNS C isc.org. Internet * ? 201.224.149.40 -> 201.224.83.242 DNS C isc.org. Internet * ? 190.35.22.44 -> 201.224.83.242 DNS C isc.org. Internet * ? 1

Re:

thanks chuck, about the other question, as to reduce the response time of my server when the domain does not exist? Thanks a lot! JM 2012/11/29 Chuck Swiger > Hi-- > > On Nov 29, 2012, at 3:00 PM, Jose Manuel Delgado G. wrote: > > I have the following problem in resolving my D

repeated several times request

Bind 9.9.1-P2 I have installed on a server with Solaris 10, when a client makes a query, this is repeated several times and it comes with the domain installed in the client machine. 172.25.3.5 -> 172.25.3.11 DNS C samsungvuieventlog.vlingo.com. Internet ? 172.25.3.11 -> 172.25.3.5 DNS R