Re: High-speed filtering boxes (Was: Re: SYN floods...)

[Deepak Jain <deepak () jain com>]

I am sure a question most of us has is, what kind of latency does your 
filtering box add? Doing something at line rate is fine, but latency is 
rather important at line speed.

Thanks,

-Deepak.

On Thu, 19 Sep 1996, Paul Frommeyer wrote:

>  
> "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 ***
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