Enhanced Traffic monitoring

Global traffic monitoring

Under Tools -> Other Settings are options that will allow you to save your traffic history to disk, preserving it between router reboots (by default it is currently kept in RAM, so it will disappear when you reboot).

You can save it to a custom location (for example, "/jffs/", or /mnt/sda1/ if you have a USB disk plugged in (which is the recommended location). Save frequency is also configurable - it is recommended to keep that frequency lower (for example, once a day) if you are saving to jffs, to reduce wearing out your flash memory. Make sure not to forget the trailing slash (/) at the end of the path.

Note that the first time you use that option, you must tell the router to create the data file. Make sure you set "Create or reset data files" to "Yes".

Also note that you will generally need to disable NAT acceleration to get accurate measurements. This isn't done automatically in the case of the global traffic monitoring, unlike with IPTraffic (more information below).

IPTraffic (monitoring per device)

Asuswrt-Merlin can track the traffic generated by each individual IP on your network. This option is called IPTraffic. This feature is only available on older models, as it's not compatible with the kernel used by the RT-AC86U and newer models.

To enable this, you must first set a custom location to store your traffic database (see above). Once again, you must also tell it to create the new data file, by enabling "Create or reset IPTraffic data files". Once done, enable the IPTraffic Monitoring option. This will add three new entries to the Traffic Monitor page selector (on the Traffic Monitoring page).

You can optionally specify which IP to monitor, or exclude some IPs from monitoring. Each IP must be separated by a comma.

It's strongly recommended that you assign a static IP to devices you wish to monitor to ensure they don't get a different IP over time, which would make the collected data somewhat unreliable. The monitoring is done per IP, NOT per MAC.

Note that IPTraffic is not compatible with NAT Acceleration (AKA CTF). When you enable it, it will automatically disable NAT acceleration.