12.4.3 Start the PPP Control Daemon

12.5 AIX PPP Client

Now that the server (mickey) is up and operational, you will configure a client (goofy) and test the connection between mickey and goofy.

12.5.1 Configuring an AIX PPP Client

You will configuring the PPP client through SMIT with the following procedure:

1. On Goofy, enter the command, smitty ppp.

2. Select the option Link Control Configuration.

3. Select the option Add a Link Configuration.

4. Fill in the fields as follows:

   PPP Subsystem Name

   goofy

   Max Server Connections

   0

   Max Client Connections

   1

   Max IP Interfaces

   1

   Max Async HDLC Attachments

   1

   You are configuring a client, therefore, you do not need more than one client connection, no server connections, and only one IP interface and async HDLC Attachments. You will only be dialing out to one server.

   Take the defaults for everything else.

5. Press Enter to add the link.

6. The file /etc/ppp/lcp_config was created. A look at this file shows the following configuration for the client.

   #cat /etc/ppp/lcp_config
   server_name goofy
   lcp_server 0
   lcp_client 1
   lcp_demand 0
   num_if 1
   num_hdlc 1
   

7. Add a TTY as shown in section 12.4.1 Adding the TTY Port. Ensure that Enable LOGIN=disable is set when configuring the TTY.

8. Configure the dial-out modem using the method in section 12.4.2 Configure the Dial-In Modem.

12.5.1.1 Start the PPP Control Daemon

Once the link is configured, you can start the control daemon pppcontrold. It is recommended that you do this from SMIT by following the same procedure as in section 12.4.3 Start the PPP Control Daemon.

Verify that the PPP interface is working by using the following command:

#ifconfig pp0
pp0: flags=6000030<POINTOPOINT,NOTRAILERS,GROUPRT,64BIT>
        inet 0.0.0.0 --> 0.0.0.0 netmask 0xff000000

The interface should display with Addresses of 0.0.0.0 set.

12.5.2 Create the Chat Dialog

A chat script is a file containing expect-send pairs separated by spaces or newline. These expect-send sequences instruct pppdial in how to dial-up and log into a remote PPP server. An example of a simple chat script follows:

' '
AT
OK
ATDT4444444
CONNECT
' '
ogin:
pppuser
ssword:
pppuser

Line by line, this script can be translated to mean:

• Expect nothing

• Send the command AT to the modem

• Expect OK to come back

• Send the modem ATDT4444444 (to make the modem dial this number)

• Expect the CONNECT response from the modem

• Send a null string.

• Expect the string ogin: from the remote system

• Send the ppp ID goofy

• Expect a prompt (ssword:) for the password.

• Send the ppp ID password that is goofy.

This is only an example and, as such, before you establish a PPP connection, dial out to the remote system and see what is required to log in and start PPP.

You should now be able to use the command: /usr/sbin/pppattachd tty0 client connect "/usr/sbin/pppdial -v -f chat_script_file" to connect to the remote server.

A sample chat script (dial_out.example) can be found in the /etc/ppp directory. You can edit this script to reflect your requirements and use it to invoke the ppp connection.

If there are any problems with the connection, see the /tmp/ppp file created in section 12.4.2.1 Capturing Diagnostic Output for diagnostic information to assist in troubleshooting the problem.

12.6 References