* 다운로드
wget http://downloads.laffeycomputer.com/current_builds/whatmask/whatmask-1.2.tar.gz
* 사용법
[root@zenoss whatmask-1.2]# whatmask 211.192.139.0/255.255.255.192
------------------------------------------------
TCP/IP NETWORK INFORMATION
------------------------------------------------
IP Entered = ..................: 211.192.139.0
CIDR = ........................: /26
Netmask = .....................: 255.255.255.192
Netmask (hex) = ...............: 0xffffffc0
Wildcard Bits = ...............: 0.0.0.63
------------------------------------------------
Network Address = .............: 211.192.139.0
Broadcast Address = ...........: 211.192.139.63
Usable IP Addresses = .........: 62
First Usable IP Address = .....: 211.192.139.1
Last Usable IP Address = ......: 211.192.139.62
