User Manual

Ports Port Restrictions
8-9
8.8.1 Locking a Port
The Lock command may be used to secure a port without disconnecting sessions. When you enter Lock,
you will be prompted to enter a password. The port will then be locked until that same password is used to
unlock it. Figure 8-19 displays an example.
Figure 8-19: Locking and Unlocking a Port
Note: Secure ports (set using the Set/Define Ports Security command) cannot be
locked.
To unlock a port without the Lock password, a privileged user must use the Unlock Port command or log
out the port using the Logout Port command. Logout will disconnect all sessions.
Note: Unlock Port is discussed on page 12-91. Logout Port is discussed on page 12-47.
The Set/Define Server Lock command, which is discussed on page 12-122, controls whether or not local
users are permitted to lock ports.
8.8.2 Enabling Signal Check
The Signal Check characteristic can be used to prevent remote connections to a port unless DSR is asserted.
This is often used to prevent Telnet logins to a port until the device attached to the port (for example, a
terminal) asserts the DSR signal, indicating that it is connected and powered on.
To enable Signal Check, use the following command:
Figure 8-20: Enabling Signal Check
8.8.3 Username/Password Protection
You can configure a port to require either a login password or a username/password pair before a login is
permitted.
Note: For detailed information on authentication, refer to Chapter 11, Security.
Local> LOCK
Password> donut (not echoed)
Verification> donut (not echoed)
Unlock password> donut (not echoed)
Local>
Local>> DEFINE PORT 3 SIGNAL CHECK ENABLED