Extron Electronics DMS 1600_2000_3200_3600 User Guide - Manual (Page 119)

DMS 1600, DMS 2000, DMS 3200, and DMS 3600 • Ethernet Connection 113
Subnetting — A Primer
It is not the purpose of this guide 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 DMS matrix switcher and the mail server gateway. To understand
subnetting at the level required to install and operate the DMS matrix switcher, you must
understand the concepts of a gateway, local and remote devices, IP addresses and octets,
and subnet masks and octets.
Gateways
The DMS matrix 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 guide, subnetting is an issue when you are using the controlling PC to
set TCP/IP and e-mail values in the matrix switcher (see
IP Settings/Options Window on
page 67 and Email Settings Page on page 93). When you are setting up the variables for
e-mail notification, which may include subnetting, the matrix switcher is the local device and
the e-mail server is the remote device.
IP Addresses and Octets
Valid IP addresses consist of four 1-, 2-, or 3-digit numeric subfields, properly called octets,
separated by dots (periods) (see figure 77). 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 77. Typical IP Address
Subnet Masks and Octets
The subnet mask (see figure 78) 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 will be
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 78. Typical Subnet Mask