Visualise IP hits from IP range

I want to visualise the amount of client IPs access our applications by capturing the IP from the ClientIP field and then applying this to the visualisations module in kibana for example.

10.10.10.0 to 10.10.10.254 Dept 1 - record how many IPs accesses from this range
10.10.11.0 to 10.10.11.254 Dept 2 - record how many IPs accesses from this range
10.10.12.0 to 10.10.12.254 Dept 3 - record how many IPs accesses from this range
10.10.13.0 to 10.10.13.254 Dept 4 - record how many IPs accesses from this range

I have tried data tables, pie charts etc but I cannot see that they add the IP hits together because it only looks like an aggregation between all the ranges.

Can someone enlighten me on this?

It sounds like you want to split your series using the "IP Range" aggregation and visualize the unique count of the same field:

This will give you the number of different IPs from each of the ranges that accessed your application at least once.