I need to count the packages on an interface after a certain filter. Let's say I want to see how many packages per second I have with Filter Syn. The command below counts these packages, but fail to find an option to see how many requests of this kind are in a given time(10 seconds let's say)
sudo tcpdump -vv dst host x.x.x..x and 'tcp[tcpflags] == tcp-syn'