Monitoring multiple ports in tcpdump

Question

I am trying to find a way to read multiple ports using tcpdump. Suppose I have two ports, p1 and p2, and I want to read the traffic moving through both ports simultaneously. Is

Answer 1

You can also select an interface (change -i any to -i en0 for example) and the communication protocol :

tcpdump -i any 'udp port 1812 or tcp port 1813'