Aggregate function for inet values in Postgres?

Question

I have data such as:

addr
10.0.0.0/32
10.0.0.1/32
10.0.0.2/32
10.0.0.3/32
10.0.0.4/32
10.0.0.5/32
10.0.0.6/32
10.0.0.7/32

I\'d like to do som