03-11-2017
Hi,
To put it as simply as possible, in any given network range the very first address and the very last address are not usable for hosts. The first address is the network address, and the last address is the broadcast address.
So for 192.168.1.0/24 you'd have:
192.168.1.0 - Network address (NOT usable for hosts)
192.168.1.1 through 192.168.1.254 - Free IPs (Usable for hosts)
192.168.1.255 - Broadcast address (NOT usable for hosts)
And for /25 sub-nets (and all others besides) it'd be the same: the first address in the range and the last address in the range are not usable for hosts.
These 2 Users Gave Thanks to drysdalk For This Post:
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LEARN ABOUT DEBIAN
cwhois
CWHOIS(3) whois client CWHOIS(3)
NAME
CWHOIS - whois client
SYNOPSIS
cwhois [-a|-F|-L|-m|-M|-r|-S|-R] [-h hostname] [-s source[[,source]...]] [-T type[[,type]...]] [-i attr[[,attr]...]] keys
cwhois [-t type]
cwhois [-v type]
DESCRIPTION
cwhois Simple whois client that gives you back output, compatiable with RIPE DB v2, if you'll ask it to.
OPTIONS
-a search all databases
-F fast raw output
-L find all Less specific matches
-m find first level more specific matches
-M find all More specific matches
-r turn off recursive lookups
-S tell server to leave out 'syntactic sugar'
-R force to show local copy of the domain object even if it contains referral
-h hostname
search alternate server
-s source[[,source]...]
search databases with source 'source'
-T type[[,type]...]
only look for objects of type 'type'
-i attr[[,attr]...]
do an inverse lookup for specified attributes
-t type
requests template for object of type 'type'
-v type
requests verbose template for object of type 'type'
HINT
Please note that most of these flags are NOT understood by non RIPE whois servers!
SEE ALSO
Website <http://www.ripe.net/tools/>
AUTHOR
CWHOIS was written by Timur Bakeyev <timur@ripe.net>.
This manual page was written by Jan Wagner <waja@cyconet.org>, for the Debian project (but may be used by others).
1.10 2006-11-03 CWHOIS(3)