USRobotics NETServer/8 - Manual (Page 238)

B-10 Addressing Schemes
Since supernet 4 can fit entirely in a single Class C address
space, it can use supernet 3’s surplus space. It is therefore given
the last Class C address space in Supernet 3’s territory, effec-
tively reducing supernet 3 to only the 7 class C networks it
needs.
Supernetting and the NETServer
In order to define a supernet on the NETServer, you must add
the network and its netmask to the netmasks table. For ex-
ample:
add netmask 234.170.168.0 255.255.248.0