Subnetting, a primer – Extron Electronics HDXP Plus Series User Guide User Manual
Page 123
HDXP Plus Series Switchers • Reference Information
117
117
Setting carriage return-line feed
Unless commanded otherwise, Telnet transmits a line feed character only (no carriage
return) to the connected switcher when you press the <Enter> key. This is the correct
setting for SIS communication with the switcher. The Telnet
set
crlf
command forces
Telnet to transmit carriage return and line feed characters when <Enter> is pressed;
however, if
crlf
is set, the SIS link with the switcher does not function properly.
Closing the link to the switcher
To close the link to the switcher, access the
Telnet
prompt by entering the escape
sequence (<Ctrl +
]>
). At the
Telnet
prompt, enter
close
.
Help
For Telnet command definitions, enter
?
at the Telnet prompt.
Exiting Telnet (Quit command)
Exit the Telnet utility by entering
quit
at the Telnet prompt. If you are connected to the
HDXP switcher, access the Telnet prompt by entering the Escape sequence (<Ctrl +
]
>).
Subnetting, a Primer
A subnet is a
subset of a network — a set of IP devices that have portions of their IP
addresses in common. It is not the purpose of this manual to describe TCP/IP protocol
in detail. However, some understanding of TCP/IP subnetting is necessary in order
to understand the interaction of the HDXP switcher and the mail server gateway. To
understand subnetting at the level required to install and operate the HDXP switcher, you
must understand the concepts of a gateway, local and remote devices, IP addresses and
octets, and subnet masks and octets.
Gateways
The HDXP switcher can communicate with the e-mail server that it 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
computer to set TCP/IP and e-mail values in the HDXP switcher (see
on
page 75 and
on page 103). When you are setting up the variables
for e-mail notification, 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 sub-fields, called “octets,”
which are separated by dots (periods) (see figure 111). Each octet can be numbered from
000 through 255. Leading zeros, 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 111.
IP Address and Octets