Chapter 5: Serial Port, Host, Device, and User Configuration
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This syntax enables
Users
to set up SSH tunnels to all serial ports with only opening a single IP port 22 in their firewall/gateway.
TCP: RAW TCP allows connections directly to a TCP socket. Communications programs like
PuTTY
also support RAW TCP. You would usually
access this protocol via a custom application.
For RAW TCP, the default port address is IP Address _ Port (4000 + serial port #)
for example,
4001–4002.
RAW TCP also enables the serial port to be tunneled to a remote
console server
, so two serial port devices can transparently interconnect
over a network (see
Chapter 5.1.6—Serial Bridging
).
RFC2217 Selecting
RFC2217
enables serial port redirection on that port. For RFC2217, the default port address is IP Address _ Port (5000 +
serial port #), that is
,
5001– 5002.
Special client software is available for Windows UNIX and Linux that supports RFC2217 virtual com ports, so a remote host can monitor and
manage remote serially attached devices, as though they were connected to the local serial port (see
Chapter 5.6—Serial Port Redirection
for details).
RFC2217 also enables the serial port to be tunneled to a remote
console server
, so two serial port devices can transparently interconnect
over a network (see
Chapter 5.1.6—Serial Bridging
).
Unauthenticated Telnet: Selecting
Unauthenticated Telnet
enables telnet access to the serial port without requiring the user to provide
credentials. When a user accesses the
console server
to telnet to a serial port, he normally is given a login prompt. With unauthenticated
telnet, the user connects directly through to a port with any
console server
login. This mode is mainly used when you have an external
system (such as
conserver
) managing user authentication and access privileges at the serial device level.
For Unauthenticated Telnet, the default port address is IP Address _ Port (6000 + serial port #) i.e. 6001 – 6002.
Accumulation Period: By default, once a connection is established for a particular serial port (such as a RFC2217 redirection or Telnet
connection to a remote computer) then any incoming characters on that port are forwarded over the network on a character by character
basis. The accumulation period changes this by specifying a period of time that incoming characters will be collected before then being sent
as a packet over the network.
Escape Character: This enables you to change the character used for sending escape characters. The default is ~.
Power Menu: This setting enables the shell power command. A user can control the power connection to a Managed Device from command
line when he is connected to the device via telnet or ssh. To operate, the Managed Device must be set up with both its Serial port
connection and Power connection configured. The command to bring up the power menu is ~p
Figure 5-8. PuTTY screen.
Single Connection: This setting limits the port to a single connection> If multiple users have access privileges for a particular port, only one
user at a time can access that port (that is, port “snooping” is not permitted).
5.1.3 SDT Mode
This setting allows port forwarding of RDP, VNC, HTPP, HTTPS, SSH, Telnet, and other LAN protocols through to computers that are locally
connected to the
console server
by their serial COM port. Port forwarding requires that you set up a PPP link over this serial port.