User Manual

Ports Port Modes
8-3
8.4 Port Modes
An SCS port can be used in one of three modes: character mode, PPP mode, or SLIP mode. The default port
mode is character mode.To configure a port to run PPP or SLIP, see the corresponding sections below.
Note: Enabling PPP or SLIP on the serial console port is not recommended.
8.4.1 Character Mode
By default, the SCS ports will start character mode when the Return or Line Feed key is pressed at startup.
Users logging into the SCS will see a Username> prompt followed by a Local> prompt. SCS commands
can be entered at this prompt to configure the unit, control logins, Telnet or Rlogin to remote hosts, start
PPP or SLIP, or display information.
Note: If the Altprompt characteristic is enabled, users will see a Login: prompt instead
of the Username> prompt. See Set/Define Server Altprompt on page 12-118 for
more details.
8.4.2 PPP Mode
A port in PPP mode runs the Point-to-Point Protocol. A port can be configured to run PPP in a number of
ways; for example, users can be authenticated, headers can be compressed, and negotiation can take place.
Because PPP isn’t designed for user interaction, the Local> prompt will not be displayed.
Both PPP and PPPDetect are enabled for all serial ports by default. PPP will automatically run once a port’s
has started up and a PPP packet is received. Because running PPP in this manner bypasses a port’s usual
authentication (using a login password or username/password combination), you should configure CHAP
or PAP authentication.
To enable a port to run PPP, use the Define Ports PPP command.
Figure 8-4: Enabling PPP
Note: For more information on PPP, refer to Chapter 7, PPP.
8.4.3 SLIP Mode
When SLIP (Serial Line Internet Protocol) and SLIPdetect (see Automatic Protocol Detection on page 8-4)
are enabled on a port, SLIP will run once that port’s start-up procedure is complete and a SLIP packet is
received.
Running SLIP in this manner bypasses a port’s usual authentication process (login password, etc.). As SLIP
doesn’t support authentication, no authentication will occur in this situation. To use authentication with
SLIP, see Chapter 11, Security.
Local>> DEFINE PORT 2 PPP ENABLED