How to Connect to BigNet with Linux PPP

First and foremost, if you haven't already, please read the Linux PPP HOWTO document, available from most Linux FTP sites (including,, and I will assume you have read this document and have PPP already installed on your Linux system.

To connect to MICHUSA.COM with PPP from Linux, you need to set up a couple of files in your PPP configuration directory (usually /etc/ppp). These files are the files options and pap-secrets. Please note that you'll need to be logged in as root to modify these files and/or start or stop the PPP daemon.

First we'll set up your options file. It should contain the following:

connect '/usr/sbin/chat -v "" ATZ OK ATDTxxx-xxxx CONNECT' defaultroute noipdefault lock modem crtscts persist asyncmap 00000000 user youriD

(Be sure to insert your local MICHUSA.COM phone number and your user ID in the appropriate places!)

You'll notice that we've put almost everything in the options file (including the chat script); this minimizes the command line you need to enter to actually start PPP.

Our connect script is very simple; it resets the modem (ATZ), then dials the telephone number and waits for a CONNECT message. Once it sees that message, the script ends, and the PPP daemon tries to start up a PPP connection. This method will work on any MICHUSA.COM telephone number.

Next, we need to set up your pap-secrets file. It should look like this:

[email protected] * yourpassword

Be sure to insert your MICHUSA.COM user ID and password where noted.

Since these files contain sensitive data, you'll probably want to make them readable only by root. Type "chmod 600 /etc/ppp/*" to do this.

You are now ready to invoke PPP. Assuming your PPP daemon is installed as /usr/sbin/pppd you would enter something like this:

/usr/sbin/pppd /dev/modem 115200

This tells the PPP daemon to start up, using the modem on /dev/modem (on most systems, this will be a symlink to the actual serial port where your modem is located), and to talk to the modem at 115,200 bps. If your modem is on another device, or if you want to work at at a slower baud rate, modify the command line appropriately.

When you want to hang up, simply kill the PPP daemon process.

Once you have PPP working, you will probably want to make things a bit easier on yourself and set up a set of shell scripts to start and stop PPP with single commands. The default PPP distribution (currently pppd-2.2.0f) contains a set of scripts you can customize to do this for you.

Please direct any questions or problems with this FAQ to [email protected].