Originally Posted by r-c-e

It means you have a /28 netblock. Download something like Solarwinds Subnet Calculator and it will tell you how many IP's you have assigned in that netblock.

0.0.0.0/32 means a singular ip
0.0.0.0/24 is a class c
0.0.0.0/16 is a class b
0.0.0.0/8 is a class a

you get the picture.