"Perry E. Metzger" <perry@piermont.com> is alleged to have said: | BTW, I would suggest that for a variety of applications, hardware | assisted filtering boxes that simply take in IP one end and put out | processed IP on the other end would be of use -- not just for this, | but also for helping in doing packet traces through high traffic | areas, for implementing firewalls, and for all sorts of other | things. Vendors, are you listening? Listening? Um, we make such a product, it's been shipping for some time. Our network address translator, product name Private Internet Exchange, can do what you ask, and with speed to spare, too. It seems to be sort of an SR-71 for packet-filtering-- our engineers haven't been able to tell me just what the upper performance bounds are because they seem to have trouble finding them. Right now we offer Fast Ethernet and Ethernet interfaces; I'm sure if there's enough market interest we'd look into doing FDDI or perhaps ATM OC3c. FWIW, last estimates I heard were that the box should scale to around 70K flows or so, which would be enough to handle a NAP connection, I should think. This is all at full line rate. More info on our web site, see http://www.cisco.com/warp/public/751/pix/index.html I've suggesteed to the PIX engineers that they look into whether it is possible to have the PIX reserve enough data structures in the IP queue to "stay ahead" of line rate flooding of SYN packets. In other words, you'd always have a connection being torn down even as more bogons came in. That would let good packets through, too, along with the evil ones. No word yet; I suspect that due to the long timeout needed for bogus source addresses that this won't be doable, but it'd sure be a nice way to pull the teeth on a SYN flood. FWIW, Cheers, Paul Paul "Corwin" Frommeyer Work Internet Engineer, CCIE Play ISP Systems Engineer Network Sorcerer At Large Cisco Systems, Inc. Paul's Fone Company pfrommey@cisco.com corwin@palas.com *** Speaking solely for myself unless otherwise noted ***