If your system has a combined A/B serial port, you can just plug a standard cable in and it will use serial port A.<BR><BR>More info here (Although i'm pretty sure his db9 -> db25 pinout is ...

The Cisco blue cable, with the Cisco db9 female (computer end) is a null modem (to Cisco devices).<BR><BR>I believe the Cisco db9f only has connection to pins 2&3 (DTE tx,rx), so if you wanted to ...

In this situation you'll need either an RJ-45 to DB-9 or RJ-45 to DB-25 adapter. The RJ-45 cable connector plugs into the adapter and the adapter plugs into the router's console port.