Originally posted by: GeneralAres
GeneralAreas: TCP incomplete connection throtteling. Your right, it will not stop any worm. However, it will (in studies by us, HP and others) slow them down. Slammer took about 14 minutes to spread, things would have been much better if this took a couple of hours (or days like CodeRed). So the setting does help
I think your way underestimating this. If you have 10x60 computers infected every minute = 600. In minute two you have 600 computers infecting 360,00 computers and in minute three 360,000 infecting 216,000,000 theoretical. IMO the patch is useless.
You're misunderstanding how the incomplete TCP connection queue functions.
Let's take a look at how common existing worms would work. The worm on an infected machine will make random attempts to connect to other hosts and drop its payload. The worm does not know if a host it is about to connect to is real or not, it just attempts to make a connection. Lets presume that the worm has been programmed with a 10 second connection timeout; that is it tries to connect to its random target and if it doesn?t get a response in 10 seconds it gives up and goes elsewhere. Now let?s presume that when it connects to a machine it can establish a connection and infect it with the payload in an average of 10 seconds.
If the machine is sitting on a broadband connection and there is no TCP connection queue present it could easily spin 1000 connection attempts. Therefore attempting connections to 6000 hosts per min.
Whereas if we compare it to a machine with a 10 un-established TCP connection queue it drops to 60 hosts per min. That?s 1/100th the growth rate of our non-queued machines.
Now, of the hosts that it attempts to connect let?s presume that 10% of them are available and directly attached to Windows OS computers (not routers, not firewalled, not *nix servers, not part of a big segmented ?A? block and currently powered on because you cant infect a machine that?s turned off
😉 ). If you don?t like my 10% figure that?s fine (after all that I did just make up) bear with me and just keep in mind that as you increase that figure my example would scale exponentially.
If we use the following formula to calculate virus growth (
formula source):
Total infections = Initial infections * rate^time
So if the initial release of the worm is on a single machine than after an hour with our Pre-SP2 machine we have a total of ~ 4.89*10^166 infections (1*600^60).
Whereas with our SP2 machine we have ~ 4.89*10^46 infections (1*6^60).
I realize this is a little long winded. But hope it shows just how much this queue can help to slow down the infections.