You could also look at Cloudshield. I was following the EveryDNS issue this weekend and this item among the regular VON press release blast jumped out at me: http://www.cloudshield.com/news_events/2006_Releases/EveryDNS%20FINAL.pdf Regards, Frank _____ From: Frank Bulk Sent: Friday, December 08, 2006 8:59 AM To: 'nanog@nanog.org' Subject: DNS - connection limit (without any extra hardware) Hi, as a comsequence of a virus diffused in my customer-base, I often receive big bursts of traffic on my DNS servers. Unluckly, a lot of clients start to bomb my DNSs at a certain hour, so I have a distributed tentative of denial of service. I can't blacklist them on my DNSs, because the infected clients are too much. For this reason, I would like that a DNS could response maximum to 10 queries per second given by every single Ip address. Anybody knows a solution, just using iptables/netfilter/kernel tuning/BIND tuning, without using any hardware traffic shaper? Thanks Best Regards Luke