Extron Electronics Matrix 12800 Series User Guide - Manual (Page 127)

Ethernet Connection, cont’d
Matrix 12800 Switchers • Ethernet Connection A-6
PRELIMINAR
Y
Subnetting — A Primer
It is not the purpose of this manual to describe TCP/IP protocol in detail. However,
some understanding of TCP/IP subnetting (a subnet is a subset of a network — a
set of IP devices that have portions of their IP addresses in common) is necessary in
order to understand the interaction of the switcher and the mail server gateway. To
understand subnetting at the level required to install and operate the switcher, you
must understand the concepts of a gateway, local and remote devices, IP addresses
and octets, and subnet masks and octets.
Gateways
The switcher can communicate with the e-mail server that the switcher uses for
e-mail notification directly (if they are on the same subnet) or the communication
can be routed via a gateway (a computer that provides a link between different
subnets).
Local and remote devices
The local and remote devices are defined from the point of view of the
function being described. In this manual, subnetting is an issue when
you are using the controlling PC to set TCP/IP values in the switcher
(see “ Ethernet protocol settings ” in chapter 3, “Virtualization/Control Software”,
and “ System Configuration page ” in chapter 5, “Web Operations”).
IP addresses and octets
Valid IP addresses consist of four 1-, 2-, or 3-digit numeric subfields, properly called
octets, separated by dots (periods) (figure A-4). Each octet can be numbered from
000 through 255. Leading zeroes, up to three digits total per octet, are optional.
Values of 256 and above are invalid.
192.168.254.254 Typical IP Address:
Octets
Figure A-4 — IP address and octets
Subnet masks and octets
The subnet mask (figure A-5) is used to determine whether the local and remote
devices are on the same subnet or different subnets. The subnet mask consists
of four numeric octets separated by dots. Each octet can be numbered from
000 through 255. Leading zeroes, up to three digits total per octet, are optional.
Each octet typically contains either 255 or 0. The octets determine whether or not
the same octets of two IP addresses are compared when determining if two devices
are on the same subnet.
255.255.0.0 Typical Subnet Mask:
Octets
255 indicates that this octet will be
compared between two IP addresses.
0 indicates that this octet will not be
compared between two IP addresses.
Figure A-5 — Subnet mask and octets