I have a router with ip (dchp enabled)
I have a working debian linux server ip with two ethernet nics
There are also several windows clients in the network.
All this is connected with the router trough a harware switch.

Problem : people on the network who dont respect the download volume.
I want to put the linux server between the router and the switch so i can monitor traffic per ip.

I made a bridge

#brctrl addbr gbridge
#brctrl gbridge addif eth0
#brctrl gbridge addif eth1
#ifconfig eth0
#ifconfig eth1
#ifconfig gbridge netmask broadcast up

The connections on the local network are working.
But the connection to my router is not working.
What am i doing wrong?
Is it possible that there is no bridging possible between an 10Mbps nic and a 100Mbps nic.

Hardware info : http://gouranga.dyndns.org/sysinfo/