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.
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LEARN ABOUT X11R4
whois.conf
WHOIS.CONF(5) Debian GNU/Linux WHOIS.CONF(5)
NAME
whois.conf - alternative WHOIS servers list for whois client
SYNOPSIS
/etc/whois.conf
DESCRIPTION
This file contains a list of WHOIS servers which can augment or override the built-in list of the client.
It's a plain text file in ASCII encoding. Each line consists of two fields: a pattern to match WHOIS object identifier and a corresponding
WHOIS server domain name.
Fields are separated by non-empty sequence of space or a tabular characters. A line starting with a hash character is a free comment and
it's not considered.
The pattern is case-insensitive extended regular expression if whois client has been compiled with POSIX regular expressions support. Oth-
erwise, simple case-insensitive suffix comparison against WHOIS object identifier is used.
Internationalized domain names (IDN) must be specified in ascii-compatible encoding (ACE) format.
EXAMPLE
.nz$ nz.whois-servers.net
# Hangul Korean TLD
.xn--3e0b707e$ whois.kr
# Private ASNs
^as645(1[2-9]|2[0-9]|3[0-4])$ whois.example.net
FILES
/etc/whois.conf
SEE ALSO
whois(1)
AUTHOR
This manual page was written by Petr Pisa <ppisar@redhat.com> and is licensed under the terms of the GNU General Public License, version 2
or higher.
Petr Pisa 9 April 2013 WHOIS.CONF(5)