Lantronix ETS Reference Manual - page 89
Ports
Security
5-17
If the Dialback call should fail for any other reason before the 80-second timeout (for example, if the number
dialed is busy), a second caller may be able to log into the ETS. This possibility can be virtually eliminated
by two steps:
1
In the Dialback string itself, issue a command to ignore incoming calls. An example of this command
is ats0=0dt555-1234.
2
Re-enable incoming call answering after the DTR signal is dropped (that is, after the dialback session
has ended). To accomplish this, the modem should be configured to reload its normal configuration
each time DTR is dropped.
When dialback is used, the ETS will verify the identity of incoming users by logging the port out and dialing
the user back at a specified number. Dialback may be configured to
1
Permit connections without dialback,
2
Log out a port and call the user back,
3
Terminate the connection when unauthorized users attempt to connect,
4
Any combination of the first three.
To use dialback for character logins, you must configure a list of authorized users. First enable Modem
Control using the Define Port Modem Control Enabled command. Then enable dialback using the Set/
Define Port Dialback Enabled command.
Figure 5-33: Define Dialback Enabled
Local>> DEFINE PORT 3 DIALBACK ENABLED