3.1 PPP Architecture
3.1.3 Configuring Cisco access servers
You can configure a Cisco access server to allow a PPP, SLIP, or AppleTalk Remote Access Protocol (ARAP) session to start automatically or to provide the router user prompt to your callers, as shown in Figure .

This autosensing feature can be accomplished by using the autoselect command issued in the line configuration mode:

Router(config)#line line-number
Router(config-line)#autoselect {arap | ppp | slip | during-login}

The autoselect command permits the access server to allow an appropriate process to start automatically when a starting character is received. The access server detects either a return character, which is the start character for an EXEC session, or the start character for one of the three protocols specified (ARAP, PPP, or SLIP). For example, PPP frames always start with a flag character having the value 7E in hexadecimal (or 01111110 in binary) format.

The during-login option of the autoselect command causes the username or password prompt to display without the need to press the Return key. This option is configured in the remote Windows 95 PC modem configuration by enabling a terminal window to be brought up after dialing. Autoselect starts when the line is active, but the system provides a username and password prompt. Figure shows a caller's session on an access server configured with the autoselect during-login command.

no exec Command

If you don’t want users to be presented with a user prompt, type no exec  at the line configuration mode. This command determines whether or not the terminal server starts an EXEC process on the line. By default, the terminal server starts EXECs on all lines. When a user tries to Telnet to a line with the no exec  command configured, the user gets no response when pressing the Return key at the login screen.