On Wed, Jul 23, 2008 at 2:03 PM, Naveen Nathan <naveen@lastninja.net> wrote:
The Endace DAG cards claim they can move 7 gbps over a PCI-X bus from the NIC to main DRAM. They claim a full 10gbps on a PCIE bus.
I wonder, has anyone heard of this used for IDS? I've been looking at building a commodity SNORT solution, and wondering if a powerful network card will help, or would the bottleneck be in processing the packets and overhead from the OS?
The first bottleneck is the interrupts from the NIC. With a generic Intel NIC under Linux, you start to lose a non-trivial number of packets around 700mbps of "normal" traffic because it can't service the interrupts quickly enough. The DAG card can be dropped in to replace the interface used for a libpcap-based application. When I tested the 1gbps PCIE version, I lost no packets to 1gbps and my capture application's CPU usage dropped to about 1/5th of what it was with the generic NIC. YMMV. Regards, Bill Herrin -- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004