Although this is the case most of the time, there is still a chance a host might send back strange packets or even generate false positives when the TCP/IP stack of the host is non-RFC-compliant or has been altered.
Iako je tako u većini slučajeva, postoji šansa da host može poslati nazad čudne pakete ili čak generisati lažno pozitivne kada je TCP/IP stek hosta ne-RFC-kompatabilan ili je promenjen.