From Deep Thought

From the good 'ol Lance Cleveland archives, a PPP (point-to-point-protocol) cheat sheet for linux modem connections, circa 1996.

Connecting PPP Through Modem

login to server

# su - 
to become superuser 
# route del default gw <host.domain.com> dev eth1
This removes the DSL gateway. 
# pppd call mindspring
Runs pppd using the call functionality.
Call functionality uses the settings in /etc/ppp/peers/mindspring to 
set the options for pppd.
The peers file sets the tty to be used for the modem (ttyS3 in our case).
The peers file then calls the chat program to run the connect script with the modem.
Chat is the program that manages the logon session with the ISP.
The chat login script is in /etc/ppp/chat-isp 
# ifconfig
Look for ppp0 listed in the network interfaces (inet addr: XXX.XXX.XXX.XXX).
If ppp0 is listed the connection has been made.
Check for the IP address assigned to our ppp connection. 
# route
Look for the ppp0 IP address as the default gateway (option set from the peers file).
If the ppp0 IP address is not the default gateway it can be set manually using route 
commands. 
<pre>
 
=Disconnecting Modem After PPP Established=
<pre>
# route add default gw <host.domain.com> dev eth1
This makes the DSL connection the default route to the Internet. 
# ps -ef f
Look for the call mindspring pppd session and make note of the process ID. 
# kill <pppd-process-id>
Killing the session should release the modem. 
# minicom
Minicom is a terminal emulator that allows you to connect to the modem directly. 
Type AT
You should get an OK response.
If you do not get the OK response: 
Type +++ 
Type ATH
This command hangs up the modem. 
Type CTRL-A 
Type X
This will exit minicom 
# route
Check to make sure the router.proactivewm.com entry is listed.
Make sure no ppp0 device entries exist