Technical data

7. In case you plan to use the PAP authentication protocol, create the file /etc/ppp/pap-secrets:

# Secrets for authentication using PAP

# client server secret IP addresses

test1 * pwdtest1 *

test2 * pwdtest2 *

In case you plan to use the CHAP authentication protocol, create the file /etc/ppp/chap-secrets:

# Secrets for authentication using CHAP

# client server secret IP addresses

test1 * pwdtest1 *

test2 * pwdtest2 *

8. Create for every ttydsxx interface that you use for dial-in server (i.e. where mgetty was started) one

/etc/ppp/options.ttydsxx file that contains the IP addresses for local and remote ends of the PPP link. In this

example, the configuration file /etc/ppp/options.ttyds01 contains:

# Options that differ for every TTY interface (i.e. IP address)

# LOCAL IP:REMOTE_IP 192.168.212.240:192.168.212.241

9. Optionally, you can use dynamic IP address assignment. Please refer to "pppd" documentation for details.

10. If you plan to allow access from the router to your network, it is necessary to allow IP forwarding: echo 1 >

/proc/sys/net/ipv4/ip_forward.

11. Execute "kill -HUP 1" to start mgetty processes (this command will inform "init" process about changes in

the /etc/inittab file).

Now, the dial-in server is running. You can use name/password pairs "test1/pwdtest1" and "test2/pwdtest2" and

CHAP/MS- CHAP protocol to gain access to the system.

A dial-in callback server allows you to gain access to your system using the callback procedure.

The callback procedure allows you to establish the connection, invoke the authentication procedure and provide

phone number where the dial-in server will call you back.

The description for setting up a dial-in callback server is based on How to set up a dial-in server on page 64

and provides only changes.

General Description

The mgetty utility is responsible for the initialization of the TTY interface and for the answering of the incoming

calls. Once the call establishment is complete, mgetty will start the modified pppd utility pppd.callback. The

pppd.callback will establish the PPP link, invoke the authentication procedure and obtain callback parameters.

Finally, pppd.callback will disconnect the link and execute the user-provided application (script) that will issue

the call back.

Setting up a dial-in callback server

1. Set up the dial-in server using How to set up a dial-in server on page 64. Finally, follow the described

procedure below to configure a dial-in callback server.

How to set up a dial-in callback server