NMAP CIDR Subnet Scan?

[mgrant1 <mgrant1 () mail uri edu>]

This concerns the NMAP -sP functionality.

The Macintosh (ducks) program WakeOnLan is capable of scanning a subnet and 
returning all addresses: private 10 addresses, 169 autoconfigured machines, 
everything, all in one list.

For example: At the University of Rhode Island, the configuration is 
131.128.subnet.X and WakeOnLan shows 131.128, 169.254, and 10 (private) 
addresses.

With NMAP, if I scan 131.128.subnet.0/24, I can see only 131.128 addresses. If 
I scan 10.1.subnet.0/24, I can see only 10 addresses. If I have to specify 
what I'm scanning, I'm obviously going to miss something I haven't looked for.

On the other hand, if I scan *.*.subnet.* or *.*.subnet.0/24 I get a slew of 
errors. Is there a better way to go about this, to scan a subnet with NMAP and 
return everything on it?

Thanks.