Basic Chat Script Enhanced for a UNIX-Style Login (System Administration Guide: Resource Management and Network Services)

System Administration Guide: Resource Management and Network Services

Basic Chat Script Enhanced for a UNIX-Style Login

The next chat script is a basic script that is enhanced for calling a remote Solaris peer or other UNIX-type peer. This chat script is used in How to Create the Instructions for Calling a Peer.

        SAY "Calling the peer\n"
        TIMEOUT 10
        ABORT BUSY
        ABORT 'NO CARRIER'
        ABORT ERROR
        REPORT CONNECT
        "" AT&F1&M5S2=255
        TIMEOUT 60
        OK ATDT1-123-555-1234
        CONNECT \c
        SAY "Connected; logging in.\n"
        TIMEOUT 5
        ogin:--ogin: pppuser
        TIMEOUT 20
        ABORT 'ogin incorrect'
        ssword: \qmypassword
        "% " \c
        SAY "Logged in.  Starting PPP on peer system.\n" 
        ABORT 'not found'
        "" "exec pppd"
        ~ \c

The following table explains the parameters of the chat script.

Script Contents	Explanation
`TIMEOUT 10`	Set initial timeout to 10 seconds. The modem's response should be immediate.
`ABORT BUSY`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT 'NO CARRIER'`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT ERROR`	Abort transmission if the modem receives this message from the opposite peer.
`REPORT CONNECT`	Gather the `CONNECT` string from the modem. Print the string.
`"" AT&F1&M5S2=255`	`&M5` – Make the modem require error control. S2=255 – Disable the TIES “+++” break sequence.
`TIMEOUT 60`	Reset the timeout to 60 seconds to allow more time for link negotiation.
`OK ATDT1-123-555-1234`	Call the remote peer by using the phone number 123-555-1212.
`CONNECT \c`	Wait for the `CONNECT` message from the opposite peer's modem.
`SAY "Connected; logging in.\n"`	Display the informative message “Connected; logging in,” to give the user status.
`TIMEOUT 5`	Change the timeout to enable quick display of the login prompt.
`ogin:--ogin: pppuser`	Wait for the login prompt. If the prompt is not received, send a RETURN and wait. Then, send the user name `pppuser` to the peer. The sequence that follows is referred to by most ISPs as the PAP login. However, the PAP login is not related in any way to PAP authentication.
`TIMEOUT 20`	Change the timeout to 20 seconds to allow for slow password verification.
`ssword: \qmysecrethere`	Wait for the password prompt from the peer. When the prompt is received, send the password `\qmysecrethere`. The `\q` prevents the password from being written to the system log files.
`"% " \c`	Wait for a shell prompt from the peer. The chat script uses the C shell. Change this value if the user prefers to log in with a different shell.
`SAY "Logged in. Starting PPP on peer system.\n"`	Display the informative message “Logged in. Starting PPP on peer system” to give the user status.
`ABORT 'not found'`	Abort the transmission if the shell encounters errors.
`"" "exec pppd"`	Start `pppd` on the peer.
`~ \c`	Wait for PPP to start on the peer.

Starting PPP right after the CONNECT \c is often called a PAP login by ISPs, though the PAP login is actually not part of PAP authentication.

The phrase ogin:--ogin: pppuser instructs the modem to send the user name pppuser in response to the login prompt from the dial-in server. pppuser is a special PPP user account name that was created for remote user1 on the dial-in server. For instructions on creating PPP user accounts on a dial-in server, refer to How to Configure Users of the Dial-in Server.