IPPP(4)                 NetBSD Kernel Interfaces Manual                IPPP(4)

NAME
     ippp -- ISDN synchronous PPP network driver

SYNOPSIS
     pseudo-device ippp count

DESCRIPTION
     The ippp driver interfaces the IP subsystem of the operating system with
     the ISDN layer so that a transport of IP packets over an ISDN link is
     possible.

     For configuration of the ippp driver, either the ipppctl(8) utility is
     used or it is configured via isdnd(8) and its associated isdnd.rc(5)
     file.

     In case an IP packet for a remote side arrives in the driver and no con-
     nection is established yet, the driver communicates with the isdnd(8)
     daemon to establish a connection.

     The driver has support for interfacing to the bpf(4) subsystem for using
     tcpdump(8) with the ippp interfaces.

     The ipppctl(8) utility is used to configure all aspects of PPP required
     to connect to a remote site.

   LINK0 and LINK1
     The link0 and link1 flags given as parameters to ifconfig(8) have the
     following meaning for the ippp devices:

     link0  Wait passively for connection.  The administrative Open event to
            the Link Control Protocol (LCP) layer will be delayed until after
            the lower layers signal an Up event (rise of ``carrier'').  This
            can be used by lower layers to support a dial-in connection where
            the physical layer isn't available immediately at startup, but
            only after some external event arrives.  Receipt of a Down event
            from the lower layer will not take the interface completely down
            in this case.

     link1  Dial-on-demand mode.  The administrative Open event to the LCP
            layer will be delayed until either an outbound network packet
            arrives, or until the lower layer signals an Up event, indicating
            an inbound connection.  As with passive mode, receipt of a Down
            event (loss of carrier) will not automatically take the interface
            down, thus it remains available for further connections.

     The link0 flag is set to off by default, the link1 flag to on.

SEE ALSO
     bpf(4), isdnd.rc(5), ipppctl(8), isdnd(8), tcpdump(8)

AUTHORS
     The ippp device driver was written by Joerg Wunsch <joerg@freebsd.org>
     and then added to ISDN4BSD by Gary Jennejohn <gary@freebsd.org>.

     This man page was written by Hellmuth Michaelis <hm@kts.org>.

NetBSD 5.0_STABLE               August 31, 2000              NetBSD 5.0_STABLE
