pppd(ADMN)                                                        pppd(ADMN)


 Name

    pppd - Point-to-Point protocol daemon

 Syntax

    /etc/pppd [-d debuglevel] [-w wait]

 Description

    The pppd daemon manages the Point-to-Point physical connection between
    the local and remote PPP host.  pppd uses the login-password technique to
    establish PPP connections to remote hosts.  pppd uses the configuration
    files associated with the ``Basic Network Utilities'' (BNU).  The method
    for configuring the serial IP link is similar to that used for uucp(C) or
    cu(C).  The serial lines may be used interchangeably for standard user
    logins, uucp logins, and PPP logins, and the standard uucp lock file
    techniques are used to share these resources.

    Upon startup, pppd opens a control channel to the PPP Streams kernel
    driver through /dev/ppcid and then listens for:

    +  PPP status requests

    +  incoming PPP connection requests

    +  outgoing PPP connection requests

    pppd listens at the port indicated in the ``pppmsg'' service specifica-
    tion (see services(SFF)).

    PPP status requests come from pppstat(ADMN), which sends requests to pppd
    through a socket. pppd gets PPP status from the PPP Streams kernel driver
    and sends that to pppstat.

    Incoming PPP connection requests come from the PPP user shell, ppp(ADMN),
    which sends requests to pppd through a socket.  pppd extracts connection
    parameters from /etc/ppphosts, passes the parameters to the PPP Streams
    kernel driver, and links the tty, through which the requester logged onto
    the local host, beneath the PPP Streams kernel driver.

    Outgoing PPP connection requests come from the PPP Streams kernel driver.
    The PPP Streams kernel driver will send a request over the control chan-
    nel to pppd with the desired IP address.  pppd searches /etc/ppphosts
    (see ppphosts(SFF)) for an entry with a host name corresponding to this
    IP address.  This entry, in conjunction with the /usr/lib/uucp/Systems
    file, is used to dial the modem (if necessary) and perform a login into
    the remote host. When the remote login process completes, pppd links the
    connected tty beneath the PPP Streams kernel driver and informs PPP that
    the link is established.

    If password authentication is required for either incoming or outgoing
    connection establishment, pppd consults the pppauth(SFF) file to acquire
    authentication information.

    Options are:

    -d debuglevel
              The value of debuglevel specifies whether debug info is logged
              to the file /usr/adm/syslog.  A value of zero logs no debug in-
              formation.  A ``non-zero'' value logs all debug information.
              The default value for debuglevel is zero.

    -w wait   The value of wait specifies the maximum number of PPP connec-
              tion requests which the system can queue while waiting for pppd
              to execute the accept system call.  Any connection requests
              that arrive when the number of queued calls equals wait are
              discarded by the system.  The default value of wait is ``5.''
              pppd passes wait as the second parameter when calling the
              listen system call.

 Files

    /dev/ppcid
    /etc/ppphosts
    /usr/lib/uucp/Systems
    /usr/lib/uucp/Devices
    /etc/ppphosts
    /etc/pppauth

 See also

    asyhdlc(ADMP), cu(C), ppp(ADMN), syslogd(ADMN), uucp(C), pppauth(SFF),
    ppphosts(SFF), ppp(ADMP), pppstat(ADMN)