Probably real simple to do, but can't seem to track down the answer.

Looking to restrict port 3000 to a machine that is running ntop from all
machines on my local LAN except for one specific machine. Basically I don't
want anyone to be able to connect to this port, except for a machine that
gathers data from that port.

I was thinking something like this would work..

$IPTABLES -A INPUT -i $INSIDE -d -p tcp --dport 3000 -j

Thanks for any help!