host <IP>: only to/from a certain host or port
src <IP>: only from a certain host or port
dst <IP>: only to a certain host or port
port <n>: only from a port number
host <IP>: only to/from a certain host or port
src <IP>: only from a certain host or port
dst <IP>: only to a certain host or port
port <n>: only from a port number