- Setting up a PPP link.
-
-Setting up a PPP link between two machines involves several steps:
-
-1. Prepare both of the machines which are to be connected:
- 1A. Make and install the pppd, pppstats and chat programs.
- 1B. Install the ppp driver in the kernel.
-The README.* files give details on this step.
-
-2. Decide on the IP addresses to be used and the level of
-authentication required by each machine, and set up the /etc/ppp
-directories accordingly.
-
-3. Set up the serial link between the two machines and run pppd on
-each machine. The two pppd's then negotiate and set up the link.
-
-Step 1 is described in the system-specific README.* files. The
-remaining steps are described below. Steps 1 and 2 need only be done
-once; step 3 is done each time the link is to be established.
-
-
-Choosing IP addresses.
-
-If a host is already connected to the Internet via a LAN such as
-Ethernet, then it will already have at least one IP address assigned,
-which will usually be the IP address of the LAN interface. In such
-cases, it is usually most convenient to use that address as the local
-IP address of the PPP interface(s) on that host. This is OK because
-the PPP interface(s) are point-to-point interfaces.
-
-If a host is not connected to the Internet, then an IP address needs
-to be assigned for it. If PPP is to be used to link it to another
-host which is connected to the Internet, is is usually most convenient
-to assign it an address on the same subnet as the remote host. If the
-other host is not connected to the Internet either, then the choice of
-IP addresses is quite arbitrary.
-
-Authentication.
-
-The level of authentication required depends on the situation, but
-generally hosts which are connected to the Internet via a LAN should
-be set up to (a) require the remote host to authenticate itself, and
-(b) restrict the remote host's choice of IP address, based on its
-identity. Otherwise the possibility exists for a remote host to
-impersonate another host on the local subnet. (However, when you are
-first installing PPP, it is probably easier to leave authentication
-disabled until you get to the point where you can successfully
-establish a link.)
-
-Setting up /etc/ppp.
-
-The /etc/ppp directory contains various files used by pppd; it should
-be created by the system administrator when installing PPP. It would
-typically contain the following files:
-
- chap-secrets Secrets used for authenticating with CHAP
- pap-secrets Secrets used for authenticating with PAP
- options Options that the system administrator wants to
- apply whenever pppd is run
-
-Since this directory contains files of secrets used for
-authentication, it should not be in a partition which is accessible
-from other hosts (e.g., exported by NFS).
-
-The `options' file contains any options which the system administrator
-wants pppd to use whenever it is run. If authentication is to be
-required, this should contain the `auth' and `usehostname' options.
-If the /etc/ppp/options file does not exist, or is not readable by
-pppd, it will refuse to run.
-
-Secrets for PAP (Password Authentication Protocol) authentication are
-stored in /etc/ppp/pap-secrets; secrets for CHAP (Cryptographic
-Authentication Protocol) are stored in /etc/ppp/chap-secrets. These
-files have the same format, and store secrets both for authenticating
-other hosts, and for authenticating this host to others. The format
-is that there are 3 or more words per line, which are:
-
- client - name of the machine to be authenticated
- server - name of the machine requiring the authentication
- secret - password or CHAP secret known by both client and server
- IP addresses - zero or more IP addresses which the client may
- use (this field is only used on the server).
-
-For example, if a LAN-connected host called "worksun" is to require
-authentication, and a host "bsdbox" is to connect to it and
-authenticate itself using CHAP, then both machines should have a
-/etc/ppp/chap-secrets file, which should contain a line something
-like:
-
- bsdbox worksun "an unguessable secret" bsdbox.my.domain
-
-Setting up syslog.
-
-pppd issues messages using syslog facility daemon (or local2 if it has
-been compiled with debugging enabled); chat uses facility local2. It
-is useful to see messages of priority notice or higher on the console.
-To see these, find the line in /etc/syslog.conf which has /dev/console
-on the right-hand side, and add `daemon.notice' on the left. This
-line should end up something like this:
+ Configuring a PPP link.
+
+After you have compiled and installed this package, there are some
+configuration files which will generally need to be set up. The
+pppd(8) man page is the best reference for the full details; this file
+outlines the configuration process for the most common case, where
+this package is being used to enable a machine to dial an ISP and
+connect to the internet. The FAQ and README.linux files also provide
+useful information about setting up PPP.
+
+Dialling an ISP.
+****************
+
+Usually, an ISP will assign an IP address to your machine, and will
+refuse to authenticate itself to you. Some ISPs require a username
+and password to be entered before PPP service commences, while others
+use PPP authentication (using either the PAP or CHAP protocols).
+
+The recommended way to set up to dial an ISP is for the system
+administrator to create a file under /etc/ppp/peers, named for the ISP
+that you will be dialling. For example, suppose the file is called
+/etc/ppp/peers/isp. This file would contain something like this:
+
+cua0 # modem is connected to /dev/cua0
+38400 # run the serial port at 38400 baud
+crtscts # use hardware flow control
+noauth # don't require the ISP to authenticate itself
+defaultroute # use the ISP as our default route
+connect '/usr/sbin/chat -v -f /etc/ppp/chat-isp'
+
+If there are any other pppd options that should apply when calling
+this ISP, they can also be placed in this file.
+
+The /etc/ppp/chat-isp file named in the last line contains the script
+for chat(8) to use to dial the ISP and go through any username/
+password authentication required before PPP service starts. Here is
+an example (for dialling an Annex terminal server):
+
+ABORT "NO CARRIER"
+ABORT "NO DIALTONE"
+ABORT "ERROR"
+ABORT "NO ANSWER"
+ABORT "BUSY"
+ABORT "Username/Password Incorrect"
+"" "at"
+OK "at&d2&c1"
+OK "atdt2479381"
+"name:" "^Uusername"
+"word:" "\qpassword"
+"annex" "ppp"
+"Switching to PPP-ppp-Switching to PPP"
+
+See the chat(8) man page for details of the script. If you are not
+sure how the initial dialog with your ISP will go, you could use
+a terminal emulator such as kermit or minicom to go through the
+process manually.
+
+If your ISP requires PAP or CHAP authentication, you will have to
+create a line in /etc/ppp/pap-secrets or /etc/ppp/chap-secrets like
+this:
+
+myhostname * "password"
+
+(Replace myhostname with the hostname of your machine.)
+
+At this point, you can initiate the link with the command:
+
+/usr/sbin/pppd call isp
+
+(N.B.: pppd might be installed in a different directory on some
+systems).
+
+This will return to the shell prompt immediately, as pppd will detach
+itself from its controlling terminal. (If you don't want it to do
+this, use the "nodetach" option.)
+
+Pppd will log messages describing the progress of the connection and
+any errors using the syslog facility (see the syslogd(8) and
+syslog.conf(5) man pages). Pppd issues messages using syslog facility
+daemon (or local2 if it has been compiled with debugging enabled);
+chat uses facility local2. It is often useful to see messages of
+priority notice or higher on the console. To see these, find the line
+in /etc/syslog.conf which has /dev/console on the right-hand side, and
+add `daemon.notice' on the left. This line should end up something
+like this: