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

ipfw: blocking syn floods - two proposed rules

2003-01-14 Thread Josh Brooks
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 syn packets with