Capture and log all LAN traffic - no access to router or firewall
I am looking for a solution for our LAN traffic monitoring and would like to use some opensource linux application.
I have a linux box with two NIC cards and what I thought is the following:
Our setup is as follows. Internet comes in through the router and into the firewall. From the firewall it goes into our switch and distributed among the workstations.
I have no access to the router or the firewall as they are centrally configured. I would like to place a device into the loop through which I could monitor the LAN traffic.
Can I put a linux box between the firewall and the switch and have all packets going through registered and logged? I have a proxy server (non transparent) and that captures some but not all. I would like to get all packets registered without interfering with the LAN etc.
Thanks for any help,