getting quick arp request

seb sebastien.thur at
Wed Sep 6 15:18:47 CEST 2006

Hi Ben,

I am indeed using XP SP2.

Some more info :

I have checked on the event viewer and I have not seen the event 4226
while I have run the code sample above.

I can still see this error (4226) recently In the log so that I must
have bumped against this limit trying to put pull this out.

I have installed today process explorer (from sysinternals).
I am not completly used to it but you can have a look at the TCP/IP
connections opened by the processes.
It appears that I have alwyas 10 connections opened (and the IP
adresses progress durning the scan from Ip adresse -> 254).

Besides I also run on the same PC angry Ip scanner 2.21. Checking using
ethereal the arp request are all dispatched quit quickly (see my mail


Something is limiting the TCP/IP connections from my python program at
10 maximum at the same time.
I do not see this limit in my code.
I did not bumped over the 4226 error.

=> Where does this limit come from.
=> How can I overcome it.

Thanks for the advice anyway.

Ben Sizer wrote:
> seb wrote:
> > I need to write a scanner that test all the IP adresses that repond on
> > a given port.
> ...
> > I am using winXP pro on a 2GHZ P4 and 512 Mo.
> If you have XP Service Pack 2, it cripples port-scanning as part of a
> 'security' fix. Broadly speaking, it limits the rate at which you can
> make connections at the OS level; this will show up as event 4226 in
> the Event Viewer if it affects you.
> -- 
> Ben Sizer

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