Table of Contents
Advertisement
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 (subset of a network) is
necessary in order to understand the interaction of the Matrix 12800 system
components (consisting of the Matrix 12800 and the FPC 5000) and the system's
interaction with the mail server gateway. To understand subnetting at the level
required to install and operate the Matrix 12800 system, you must understand the
concepts of a local device, a remote device, and a gateway, as well as IP address
fields and subnet mask fields and subfields.
In order for the FPC 5000 and the Matrix 12800 BME to communicate using TCP/IP
protocol, these devices must be on the same subnet and communicate directly,
without going through a gateway.
The e-mail server that the switcher uses for e-mail notification can communicate
with the e-mail server directly (on the same subnet) or be routed via a gateway.
The local and remote devices are defined from the point of view of the function
being described. In this manual there are two areas in which subnetting is described:
•
Logging the FPC 5000 onto the Matrix 12800 (see Starting Up the Controller and
Logging In and Out), in which the FPC 5000 is the local device and the
Matrix 12800 BME 0 is the remote device.
•
Using the FPC 5000 to set TCP/IP and e-mail values in the Matrix 12800
BME 0 (see TCP/IP Screen), in which case the Matrix 12800 is the local device
and the e-mail server is the remote device.
Valid IP addresses consist of four 1-, 2-, or 3-digit numeric subfields separated by
dots (periods). Each subfield can be numbered from 000 through 255. Leading
zeroes, up to 3 digits total per subfield, are optional. Values of 256 and above are
invalid.
The subnet mask field 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 subfields separated by dots. Each subfield can be numbered from 000
through 255. Leading zeroes, up to 3 digits total per subfield, are optional. Each
subfield typically contains either 255 or 0.
To determine the subnet, the local device's IP address is compared to the remote
device's IP address (figure 3-24). Each address's subfields are compared or not
compared, depending on the value in the related subnet mask subfield.
•
If a subnet mask subfield contains the value 255, the related subfields of the
local device's address and the remote device's IP address are unmasked.
Unmasked subfields are compared (indicated by ? in figure 3-24).
•
If the subnet mask subfield contains the value 0, the related subfields of the
local device's and remote device's IP addresses are masked. Masked
subfields are not compared (indicated by X in figure 3-24).
If the unmasked subfields of the two IP addresses match (indicated by = in
figure 3-24) (example 1), the two addresses are on the same subnet. If the two
unmasked fields do not match (indicated by ≠ ) (example 2 and example 3), the
addresses are not on the same subnet.
Local IP Address:
Remote IP Address:
Figure 3-24 — Comparing the IP addresses
Example 1
192.168.254.254
Subnet Mask:
255.255.0.0 ( ? . ? . X . X)
192.168.2.25
Match?:
=.=. X . X — Match
(Same subnet)
FPC 5000 Front Panel Controller • Matrix 12800 Operation
Example 2
Example 3
192.168.254.254
192.168.254.254
255.255.0.0 ( ? . ? . X . X)
255.255.0.0 ( ? . ? . X . X)
190.190.2.25
192.190.2.25
≠.≠. X . X — No match
=.≠. X . X — No match
(Different subnet)
(Different subnet)
3-37
Advertisement
Table of Contents
