How to make such realtime traffic monitoring?

Question

Computer networks

ASUS routers have the ability to view the current traffic
graph event.asus.com/2012/nw/dummy_ui/en/Main_TrafficMon...
Tell me , what tool can I use to get the current channel load? I mean not visually, but dry numbers of the current load. I heard about net flow, but it seems to me that it would be unprofitable to use it on weak routers.
In general, my main task is to monitor the channel load on a web server with division by domains. Maybe there will be advice on measurement algorithms?

Answer 1

This is all done through the SNMP protocol - once in a while the value of transmitted packets is collected, subtracted from the previous value, and a graph is drawn. There are already a lot of tools for this, but if you want, you can make your own. The most popular is MRTG.
And Netflow for these purposes - that from a gun on sparrows.

Answer 2

In general, my main task is to monitor the channel load on a web server with division by domains. Maybe there will be advice on measurement algorithms?

I understand correctly that your web server serves several domain names and you want to know the statistics of requests for domain names? In this case, I think both SNMP and netflow are unlikely to help you. The matter is that generally, these requests differ in heading "Host:" HTTP messages. I doubt your router's SNMP agent will provide this information. In netflow, these parameters are also not taken into account. If I understand your task correctly, it's more logical to parse access logs. The resulting data can be sent to collectd/graphite, for example.