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# 28.3 Using Kernel PPP

Parts originally contributed by Gennady B. Sorokopud and Robert Huff.

> Warning: This section applies and is valid only for FreeBSD 7.X.

## 28.3.1 Setting Up Kernel PPP

Before you start setting up PPP on your machine, make sure that `pppd` is located in `/usr/sbin` and the directory `/etc/ppp` exists.

`pppd` can work in two modes:

1. As a “client” — you want to connect your machine to the outside world via a PPP serial connection or modem line.

2. As a “server” — your machine is located on the network, and is used to connect other computers using PPP.

In both cases you will need to set up an options file (`/etc/ppp/options` or `~/.ppprc` if you have more than one user on your machine that uses PPP).

You will also need some modem/serial software (preferably `comms/kermit`), so you can dial and establish a connection with the remote host.

## 28.3.2 Using `pppd` as a Client

Based on information provided by Trev Roydhouse.

The following `/etc/ppp/options` might be used to connect to a Cisco terminal server PPP line.

    crtscts         # enable hardware flow control
    modem           # modem control line
    noipdefault     # remote PPP server must supply your IP address
                    # if the remote host does not send your IP during IPCP
                    # negotiation, remove this option
    passive         # wait for LCP packets
    domain ppp.foo.com      # put your domain name here

    :remote_ip    # put the IP of remote PPP host here
                    # it will be used to route packets via PPP link
                    # if you didn't specified the noipdefault option
                    # change this line to local_ip:remote_ip

    defaultroute    # put this if you want that PPP server will be your
                    # default router

To connect:

1. Dial to the remote host using Kermit (or some other modem program), and enter your user name and password (or whatever is needed to enable PPP on the remote host).

2. Exit Kermit (without hanging up the line).

3. Enter the following:

       # /usr/sbin/pppd /dev/tty01 19200

   Be sure to use the appropriate speed and device name.

Now your computer is connected with PPP. If the connection fails, you can add the `debug` option to the `/etc/ppp/options` file, and check console messages to track the problem.

Following `/etc/ppp/pppup` script will make all 3 stages automatic:

    #!/bin/sh
    pgrep -l pppd
    pid=`pgrep pppd`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill ${pid}
    fi
    pgrep -l kermit
    pid=`pgrep kermit`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing kermit, PID=' ${pid}
            kill -9 ${pid}
    fi

    ifconfig ppp0 down
    ifconfig ppp0 delete

    kermit -y /etc/ppp/kermit.dial
    pppd /dev/tty01 19200

`/etc/ppp/kermit.dial` is a Kermit script that dials and makes all necessary authorization on the remote host (an example of such a script is attached to the end of this document).

Use the following `/etc/ppp/pppdown` script to disconnect the PPP line:

    #!/bin/sh
    pid=`pgrep pppd`
    if [ X${pid} != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill -TERM ${pid}
    fi

    pgrep -l kermit
    pid=`pgrep kermit`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing kermit, PID=' ${pid}
            kill -9 ${pid}
    fi

    /sbin/ifconfig ppp0 down
    /sbin/ifconfig ppp0 delete
    kermit -y /etc/ppp/kermit.hup
    /etc/ppp/ppptest

Check to see if `pppd` is still running by executing `/usr/etc/ppp/ppptest`, which should look like this:

    #!/bin/sh
    pid=`pgrep pppd`
    if [ X${pid} != "X" ] ; then
            echo 'pppd running: PID=' ${pid-NONE}
    else
            echo 'No pppd running.'
    fi
    set -x
    netstat -n -I ppp0
    ifconfig ppp0

To hang up the modem, execute `/etc/ppp/kermit.hup`, which should contain:

    set line /dev/tty01	; put your modem device here
    set speed 19200
    set file type binary
    set file names literal
    set win 8
    set rec pack 1024
    set send pack 1024
    set block 3
    set term bytesize 8
    set command bytesize 8
    set flow none

    pau 1
    out +++
    inp 5 OK
    out ATH0\13
    echo \13
    exit

Here is an alternate method using `chat` instead of `kermit`:

The following two files are sufficient to accomplish a `pppd` connection.

`/etc/ppp/options`:

    /dev/cuad1 115200

    crtscts		# enable hardware flow control
    modem		# modem control line
    connect "/usr/bin/chat -f /etc/ppp/login.chat.script"
    noipdefault	# remote PPP serve must supply your IP address
    	        # if the remote host doesn't send your IP during
                    # IPCP negotiation, remove this option
    passive         # wait for LCP packets
    domain your.domain	# put your domain name here

    :		# put the IP of remote PPP host here
    	        # it will be used to route packets via PPP link
                    # if you didn't specified the noipdefault option
                    # change this line to local_ip:remote_ip

    defaultroute	# put this if you want that PPP server will be
    	        # your default router

`/etc/ppp/login.chat.script`:

> Note: The following should go on a single line.

    ABORT BUSY ABORT 'NO CARRIER' "" AT OK ATDTphone.number
      CONNECT "" TIMEOUT 10 ogin:-\\r-ogin: login-id
      TIMEOUT 5 sword: password

Once these are installed and modified correctly, all you need to do is run `pppd`, like so:

    # pppd

## 28.3.3 Using `pppd` as a Server

`/etc/ppp/options` should contain something similar to the following:

    crtscts                         # Hardware flow control
    netmask 255.255.255.0           # netmask (not required)
    192.114.208.20:192.114.208.165  # IP's of local and remote hosts
                                    # local ip must be different from one
                                    # you assigned to the Ethernet (or other)
                                    # interface on your machine.
                                    # remote IP is IP address that will be
                                    # assigned to the remote machine
    domain ppp.foo.com              # your domain
    passive                         # wait for LCP
    modem                           # modem line

The following `/etc/ppp/pppserv` script will tell pppd to behave as a server:

    #!/bin/sh
    pgrep -l pppd
    pid=`pgrep pppd`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill ${pid}
    fi
    pgrep -l kermit
    pid=`pgrep kermit`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing kermit, PID=' ${pid}
            kill -9 ${pid}
    fi

    # reset ppp interface
    ifconfig ppp0 down
    ifconfig ppp0 delete

    # enable autoanswer mode
    kermit -y /etc/ppp/kermit.ans

    # run ppp
    pppd /dev/tty01 19200

Use this `/etc/ppp/pppservdown` script to stop the server:

    #!/bin/sh
    pgrep -l pppd
    pid=`pgrep pppd`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill ${pid}
    fi
    pgrep -l kermit
    pid=`pgrep kermit`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing kermit, PID=' ${pid}
            kill -9 ${pid}
    fi
    ifconfig ppp0 down
    ifconfig ppp0 delete

    kermit -y /etc/ppp/kermit.noans

The following Kermit script (`/etc/ppp/kermit.ans`) will enable/disable autoanswer mode on your modem. It should look like this:

    set line /dev/tty01
    set speed 19200
    set file type binary
    set file names literal
    set win 8
    set rec pack 1024
    set send pack 1024
    set block 3
    set term bytesize 8
    set command bytesize 8
    set flow none

    pau 1
    out +++
    inp 5 OK
    out ATH0\13
    inp 5 OK
    echo \13
    out ATS0=1\13   ; change this to out ATS0=0\13 if you want to disable
                    ; autoanswer mode
    inp 5 OK
    echo \13
    exit

A script named `/etc/ppp/kermit.dial` is used for dialing and authenticating on the remote host. You will need to customize it for your needs. Put your login and password in this script; you will also need to change the input statement depending on responses from your modem and remote host.

    ;
    ; put the com line attached to the modem here:
    ;
    set line /dev/tty01
    ;
    ; put the modem speed here:
    ;
    set speed 19200
    set file type binary            ; full 8 bit file xfer
    set file names literal
    set win 8
    set rec pack 1024
    set send pack 1024
    set block 3
    set term bytesize 8
    set command bytesize 8
    set flow none
    set modem hayes
    set dial hangup off
    set carrier auto                ; Then SET CARRIER if necessary,
    set dial display on             ; Then SET DIAL if necessary,
    set input echo on
    set input timeout proceed
    set input case ignore
    def \%x 0                       ; login prompt counter
    goto slhup

    :slcmd                          ; put the modem in command mode
    echo Put the modem in command mode.
    clear                           ; Clear unread characters from input buffer
    pause 1
    output +++                      ; hayes escape sequence
    input 1 OK\13\10                ; wait for OK
    if success goto slhup
    output \13
    pause 1
    output at\13
    input 1 OK\13\10
    if fail goto slcmd              ; if modem doesn't answer OK, try again

    :slhup                          ; hang up the phone
    clear                           ; Clear unread characters from input buffer
    pause 1
    echo Hanging up the phone.
    output ath0\13                  ; hayes command for on hook
    input 2 OK\13\10
    if fail goto slcmd              ; if no OK answer, put modem in command mode

    :sldial                         ; dial the number
    pause 1
    echo Dialing.
    output atdt9,550311\13\10               ; put phone number here
    assign \%x 0                    ; zero the time counter

    :look
    clear                           ; Clear unread characters from input buffer
    increment \%x                   ; Count the seconds
    input 1 {CONNECT }
    if success goto sllogin
    reinput 1 {NO CARRIER\13\10}
    if success goto sldial
    reinput 1 {NO DIALTONE\13\10}
    if success goto slnodial
    reinput 1 {\255}
    if success goto slhup
    reinput 1 {\127}
    if success goto slhup
    if < \%x 60 goto look
    else goto slhup

    :sllogin                        ; login
    assign \%x 0                    ; zero the time counter
    pause 1
    echo Looking for login prompt.

    :slloop
    increment \%x                   ; Count the seconds
    clear                           ; Clear unread characters from input buffer
    output \13
    ;
    ; put your expected login prompt here:
    ;
    input 1 {Username: }
    if success goto sluid
    reinput 1 {\255}
    if success goto slhup
    reinput 1 {\127}
    if success goto slhup
    if < \%x 10 goto slloop         ; try 10 times to get a login prompt
    else goto slhup                 ; hang up and start again if 10 failures

    :sluid
    ;
    ; put your userid here:
    ;
    output ppp-login\13
    input 1 {Password: }
    ;
    ; put your password here:
    ;
    output ppp-password\13
    input 1 {Entering SLIP mode.}
    echo
    quit

    :slnodial
    echo \7No dialtone.  Check the telephone line!\7
    exit 1

    ; local variables:
    ; mode: csh
    ; comment-start: "; "
    ; comment-start-skip: "; "
    ; end:

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