There are cases where you want to monitor a specific type of connection going from/to & through your router. As an example the following example keeps track of DNS requests towards name servers.

watch -tn5 “conntrack -L -p udp –dport 53 | sort -nrk3; echo; conntrack -L -p tcp –dport 53 | sort -nrk3”

53 of course refers to DNS and in the above case includes both udp and tcp. You can change this to any port of relevancy (e.g. 443) to change the command scope.