On Thu, Jun 13, 2013 at 3:38 PM, Phil Fagan <philfagan@gmail.com> wrote:
I would assume something FreeBSD based might be best....
Meh... personal choice. I prefer Linux, mostly because I know it best and most network application development is taking place there.
On Thu, Jun 13, 2013 at 4:37 PM, Phil Fagan <philfagan@gmail.com> wrote:
I really like the idea of a stripe of linux boxes doing the heavy lifting. Any suggestions on platforms, card types, and chip types that might be better purposed at processing this type of data?
Personally, I'd use modern-ish Intel Ethernet NICs. They seem to have the best support in the kernel.
I assume you could write some fast Perl to ingest and manage the tables? What would the package of choice be for something like this?
Heh... "fast" Perl. As for programming the processing, I would do as much as possible in the kernel, as passing packets off to userland really slows everything down. If you really need to, I'd do something with Go and/or C these days. Using iptables and the "string" module to match patterns, you can chew through packets pretty efficiently. This comes with the caveat that this can only match against strings contained within a single packet; this doesn't do L4 stream reconstruction. You can do some incredibly-parallel stuff with ntop's PF_RING code, if you blow more traffic through a single core than it can chew through. It all depends on what you're trying to do. --j
On Thu, Jun 13, 2013 at 3:11 PM, Jonathan Lassoff <jof@thejof.com> wrote:
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 <ewust@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
-- Phil Fagan Denver, CO 970-480-7618
-- Phil Fagan Denver, CO 970-480-7618