IPID sequencability class is: All zeros (Nmap Idle Scan with zombie host)

["Simon Jolle \"sjolle\"" <urandomdev () gmail com>]

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Hi Security specialists

I try to spoof packets from another host (in my lab environment). Its a
Windows XP SP2 machine. In nmap this feature is called idle scan.

> # nmap -P0 -sI x.x.x.x:443 example.com
> Starting Nmap 4.20 ( http://insecure.org ) at 2007-12-08 22:03 CET 
> Idlescan zombie 192.168.111.113 (192.168.111.113) port 443 cannot be
> used because IPID sequencability class is: All zeros.  Try another
> proxy. QUITTING!

What does the error message "port x cannot be used because IPID
sequencability class is: All zeros" mean?

I tried several different ports.

cheers
Simon
- --
actually, I think Windows Vista has done more than virtually any OS
release to promote the use of Linux (Slashdot Kommentar, 4. Oct 07)

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