Da alcuni documenti del reaver, che ho trovato qui :
Some poor WPS implementations will drop a connection on the floor when an invalid pin is supplied instead of responding with a NACK message as the specs dictate. To account for this, if an M5/M7 timeout is reached, it is treated the same as a NACK by default. However, if it is known that the target AP sends NACKS (most do), this feature can be disabled to ensure better reliability. This option is largely useless as Reaver will auto-detect if an AP properly responds with NACKs or not:
reaver -i mon0 -b 00:01:02:03:04:05 --nack
Quindi riguardo al tuo problema:
The speed at which Reaver can test pin numbers is entirely limited by the speed at which the AP can process WPS requests. Some APs are fast enough that one pin can be tested every second; others are slower and only allow one pin every ten seconds. Statistically, it will only take half of that time in order to guess the correct pin number.
È possibile che tu abbia semplicemente un AP veramente molto lento?
O ottieni altri messaggi di errore / log?