Re: ipfw: blocking syn floods - two proposed rules

2003-01-15 Thread Richard A Steenbergen
On Wed, Jan 15, 2003 at 03:36:28PM +0100, Andre Oppermann wrote: > In a recent study my diploma students found that out of a dataset of > 9 million TCP SYN in real life traffic (Sunsite Switzerland, five > popular newspaper sites) approximatly 5% did not have the MSS option > set. We did not manage

Re: ipfw: blocking syn floods - two proposed rules

2003-01-15 Thread Andre Oppermann
"Louis A. Mamakos" wrote: > > > > > My goal is to create an ipfw rule that stops normal syn floods by blocking > > ALL syn packets that have no MSS set. > > > > My understanding is that there is no legitimate packet that is a SYN and > > has no MSS, and further, most of the kiddie tools in existen

Re: ipfw: blocking syn floods - two proposed rules

2003-01-15 Thread Louis A. Mamakos
> > My goal is to create an ipfw rule that stops normal syn floods by blocking > ALL syn packets that have no MSS set. > > My understanding is that there is no legitimate packet that is a SYN and > has no MSS, and further, most of the kiddie tools in existence for syn > flooding do indeed send sy