I have a limited ADSL connection in my house. I want to monitor how much traffic each device connected to my router is using. I use a D-Link DSL-2730U as router. As far as I know there is no custom firmware available for my router.
Is there a way to monitor traffic based on MAC addresses?
Without using additional hardware or software on a dedicated computer it is most likely impossible to do exactly wnat you want, and you have not specified exactly how far you are willing to go (in terms of spending money/time) to accomplish your goal.
Note that MAC address can be changed on most platforms so someone could still evade your monitoring by spoofing and using another user's MAC address while their devices are not connected to the network.
Based on the hardware you have at your disposal the best you could do is create static DHCP leases on your router so that all devices always get the same IP address. Then you could use traffic shaping / QoS to limit bandwidth usage for some of the IP addresses.
If your router can be put in bridge mode, you could consider purchasing Ubiquiti EdgeRouter Lite. For a price of 100 USD with the current firmware (1.7.0) you will also get DPI monitoring which will allow you to see the traffic breakdown per protocol for each IP address. DPI filtering is scheduled to appear in future firmware updates. You can use NetFlow with this router and an external NetFlow collector.
An alternative to this, assuming that your current router supports SNMP would be to use something like Observium. However, you might need to purchase the professional version to get all the features you need.
