Hi, I've tried to listen to the Frame Relay interface: tcpdump -i fr0 (I have a Frame Relay board in the computer configured as fr0). But I got an error : "unknown interface". tcpdump works ok just for lo, eth0: tcpdump -i eth0 What can I do to listen to the fr0 ? Alexander Rier e-mail: alexr@gezernet.co.il Tel: 972-3-5340807 972-52-442549