Are you trying to block flows from becoming established, knowing what you're looking for ahead of time, or are you looking to examine a stream of flow establishments, and will snipe off some flows once you've determined that they should be blocked?
If you know a 5-tuple (src/dst IP, IP protocol, src/dst L4 ports) you want to block ahead of time, just place an ACL. It depends on the platform, but those that implement them in hardware can filter a lot of traffic very quickly. However, they're not a great tool when you want to dynamically reconfigure the rules. For high-touch inspection, I'd recommend a stripe of Linux boxes, with traffic being ECMP-balanced across all of them, sitting in-line on the traffic path. It adds a tiny bit of latency, but can scale up to process large traffic paths and apply complex inspections on the traffic. Cheers, jof On Thu, Jun 13, 2013 at 12:32 PM, Eric Wustrow <ew...@umich.edu> wrote: > Hi all, > > I'm looking for a way to block individual TCP flows (5-tuple) on a 1-10 gbps > link, with new blocked flows being dropped within a millisecond or so of > being > added. I've been looking into using OpenFlow on an HP Procurve, but I don't > know much in this area, so I'm looking for better alternatives. > > Ideally, such a device would add minimal latency (many/expandable CAM > entries?), can handle many programatically added flows (hundreds per > second), > and would be deployable in a production network (fails in bypass mode). Are > there any > COTS devices I should be looking at? Or is the market for this all under > the table to > pro-censorship governments? > > Thanks, > > -Eric
