On several occasions, I've had routers (3640s and 2611s) fail and appear to be completely dead . . . i.e. unable to ping/telnet, ISDN modules fail to connect, and backdoor modem access via console also fails. After having my circuit tested and determined to be good and clean, I've dispatched Cisco and after replacing a failed Async Module the router recovered completely . . . serial (circuit), ISDN and backdoor modem function normally. So, here's my question . . . Why is a failed Async module causing complete router failure?
