Two weeks ago I switched to FTTH from Xs4all, and I got an new modem, a Fritz!box 7490. Internet from the FTU is connected to the Lan1 port, TV is connected to Lan4, the other ports are used by the internal network. The Fritz 7490 doesn't do SNMP, so I've been looking for a way to monitor the traffic. And this is what I've done:
Beware: Following the upgrade to Fritz!OS 6.20 this construction proved to be unstable, one of the commands or the telnetd contains a memory-leak, causing the modem to crash and reboot periodically.