Recently (this year...) I've noticed increasing number of ip range scans of various types that envolve one or more ports being probed for our entire ip blocks sequentially. At first I attributed all this to various windows viruses, but I did some logging with callbacks soon after to origin machine on ports 22 and 25) and substantial number of these scans are coming from unix boxes. I'm willing to tolerate some random traffic like dns (although why would anybody send dns requests to ips that never ever had any servers on them?), but scans on random port of all my ips - that I consider to be a serious security issue and I'm getting tired of it to say the least (not to mention that its drain on resources as for example routers have to answer and try to route all the requests or answer back that they could not). So I'm wondering what are others doing on this regard? Is there any router configuration or possibly intrusion detection software for linux based firewall that can be used to notice as soon as this random scan starts and block the ip on temporary basis? Best would be some kind of way to immediatly detect the scan on the router and block it right there... Any people or networks tracking this down to perhaps alert each other? -- William Leibzon Elan Networks william@elan.net