TCPdump capturing


I run tcpdump by using this command:
screen -dm tcpdump -s0 -w/tmp/capture-Started-date +%Y%m%d-%H%M%Z.pcap -C75 udp

I noticed that the packet capture works great for my eht0 device. Some calls come in through an OpenVPN tun0 interface, and also will work on an internal interface eth1. eth0 is a card that is directly connected to the internet with a public IP. The capture ONLY has packets that are traveling through eth0, not on tun0 or eth1. Is there something I can add to that command so that it captures packets for all interfaces on the system?


man tcpdump will show that you need to specify the interface , hence

screen -dm tcpdump -i tun0 -s0 -w/tmp/capture-Started-date +%Y%m%d-%H%M%Z.pcap -C75 udp