From a text editor such as vi or emacs, open the /etc/inittab file.
Add one line for each modem you plan to use.
For example, enter S0:2345:respawn:/sbin/mgetty -D ttyS0 where -D is the parameter for a data modem and ttySO is the device identifier.
The device identifier value varies according to your hardware. For example, ttyS0 is associated with COM1 and ttyS1 is associated with COM2.
Note:
ttyS0 identifies a serial modem. Modify these instructions as required if you are using a different type of modem.
Save your changes.
Open the /etc/mgetty+sendfax/login.config file.
Remove the # sign from the AutoPPP line to uncomment it.
Edit the line to include a reference to the options file by specifying file /etc/ppp/options. For example: /AutoPPP/ - a_ppp /usr/sbin/pppd file /etc/ppp/options.
Save your changes.
Open the /etc/ppp/pap-secrets file to set up Password Authentication Protocol (PAP) authentication:
Edit the file so it consists of one line containing the following characters: * * * For example:
# Secrets for authentication using PAP
# client server secret IP address
* * "" *
These settings enable any registered user to log in. Alternatively, you could specify user names, passwords, and IP addresses.
Save your changes.
Open the appropriate options file for your modem.
For example, if your modem is connected to ttys0, open the /etc/ppp/options.ttyS0 file. Include a <serverIP>:<clientIP> entry for each tty. You must separate the server IP address and the client IP address with a colon.
The default <serverIP>:<clientIP> entry for each tty is 192.168.25.10:192.168.25.20 where 192.168.25.10 is the server IP and 192.168.25.20 is the client IP.
Save your changes.
Open the /etc/ppp/options file. Verify that the client PPP supports the options listed in the following table. Edit the file, if necessary, and save your changes.
lock
Creates a lock file that has exclusive access to a specific device.
-detach
Prohibits the pppd process from forking and becoming a background process. This happens when a serial device is specified.
modem
Sets up the server to use modem control lines. The client waits for a signal from the modem before opening a serial device (default behavior). You can change this handshake if necessary.
crtscts
Specifies hardware flow control.
proxyarp
Let the client appear as if it is on the same LAN as its peers.
asyncmap 0
Prohibits the pppd process from setting up and using escape control sequences.
