Bandwidth Hugers how to find them

So it really depends what equipment you are working with.  Some firewalls will provide this information as far as who is consuming your internet bandwidth, cisco routers will do this - this would be useful for internet as well as private metro-e or mpls connections.  Typically netflow is involved.  The firewall and router can show you this, but there are 3rd party netflow collectors as well.  In this case you have to have equipment that will support netflow.  Scrutinizer make a nice netflow collector as well as solar winds.

If you don't have equipment that supports netflow, then you can use something like NTOPng - which basically spans a port or ports and reports on basically the same type of information.

we got a fortigate 100D
firmware ver: v5.2.10,build742

Ok I am not familiar with fortigate - I'm a cisco guy ;)  However, you can google whether or not it supports some type of netflow functionality and if it does it might be able to show you the information you want or at least be able to forward netflow data to a netflow collector which will let you look at exactly who is using how much bandwidth at any given time.

You may also be able to check on the switch level if you have managed switches?

We Have Dell PowerConnect 6248 mnage switches

Install PRTG, free license is unlimited for 30 days, and you can just monitor the ports, assuming we are not talking 1000's.  You can just track down high traffic ports and ID the user.

Not as elegant as netflow, but works in a pinch.  It is a great product to have handy for monitoring or occassional troubleshooting.

The 6248 is layer 3 and supports sflow

A quick google implies that the fortigate can provide the info too, never used one.

quick worthwhile read too, towards the end custom reports in the fortigate:

http://networkengineering.stackexchange.com/questions/18947/how-do-i-pinpoint-bandwidth-consumers-on-my-fortigate

i would first clarify what the author mean by "bandwidth hungers", hungers used most data in a period of past, or hungers requiring high download or upload speed at the moment? they are different apps.

if you are using Windows 10, good news for you is most of the required features are built-in now. if you are looking which apps consumed more data in the past, please check below cNET article.

https://www.cnet.com/au/how-to/monitor-your-data-usage-in-windows-10/

if you concern more about network performance against each app, please check his how-to article

https://askleo.com/how_do_i_monitor_network_activity_on_my_windows_machine/comment-page-1/