SYN floods (was: does history repeat itself?)

Tue Sep 10 18:21:20 UTC 1996

Alec H. Peterson writes:
> 
> Alexis Rosen writes:
> >That's why I was talking about filtering at a router just upstream from
> >the dial-access box.
> >
> >FWIW, even with a thousand very busy modems, I'm pretty sure that even a
> >small cisco is up to the job. They just don't generate all that much traffic.
> 
> Could be, although I'd want to see this before I bet the farm on it.
> I'm not sure how efficient crisco's filtering algorithm is...

I would. As a point of reference, we have filters on two fairly busy T1s,
which between them account for more then 500 modems worth of traffic and
a *lot* more besides (all of VTW's traffic, for example). Putting filters
on these, both an an AGS+/4, didn't make an enormous difference in CPU- it's
still <30%. Surely a 2500 series box could handle that much. (It's 68030 vs.
68040, but we're at 30% utilization, and we're doing other things on that
box.)

/a
---
Alexis Rosen   Owner/Sysadmin,
PANIX Public Access Unix & Internet, NYC.
alexis at panix.com