Port Mirroring.
Copy traffic from specified interfaces to MIRROR port.
Tested kernel version: 2.6.23, 2.6.29, 2.6.37
$ make
$ sudo make install
$ sudo modprobe mirror mirror=ethA/ethB/ethC@ethZ
Mirror ethA, ethB, ethC, ... to ethZ
$ sudo modprobe mirror mirror=eth2/eth3@eth0
Mirror eth2 and eth3 to eth0.
$ sudo modprobe mirror mirror=eth0@eth1
Mirror eth0 to eth1.