## 18.3 Using Kernel PPP 

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

### 18.3.1 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.
  1. 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`](http://pkgsrc.se/comms/kermit)), so you can dial and establish a connection with the remote host.

### 18.3.2 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).
  1. Exit  **kermit**  (without hanging up the line).
  1. Enter the following:
      
      # /usr/src/usr.sbin/pppd.new/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
    ps ax |grep pppd |grep -v grep
    pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill ${pid}
    fi
    ps ax |grep kermit |grep -v grep
    pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'`
    if [ "X${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=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'`
    if [ X${pid} != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill -TERM ${pid}
    fi
    
    ps ax |grep kermit |grep -v grep
    pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'`
    if [ "X${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=`ps ax| grep pppd |grep -v grep|awk '{print $1;}'`
    if [ X${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/cuaa1 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 ATDT<phone.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


### 18.3.3 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
    ps ax |grep pppd |grep -v grep
    pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill ${pid}
    fi
    ps ax |grep kermit |grep -v grep
    pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'`
    if [ "X${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
    ps ax |grep pppd |grep -v grep
    pid=`ps ax |grep pppd |grep -v grep|awk '{print $1;}'`
    if [ "X${pid}" != "X" ] ; then
            echo 'killing pppd, PID=' ${pid}
            kill ${pid}
    fi
    ps ax |grep kermit |grep -v grep
    pid=`ps ax |grep kermit |grep -v grep|awk '{print $1;}'`
    if [ "X${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 ATS00\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:




CategoryHandbook
CategoryHandbook-pppandslip