NAME

       ng_gif — generic tunnel interface netgraph node type

SYNOPSIS

       #include <netgraph/ng_gif.h>

DESCRIPTION

       The  ng_gif  netgraph  node  type  allows  gif(4)  interfaces to interact with the netgraph(4) networking
       subsystem.  Once the ng_gif module is loaded in the kernel, a node  is  automatically  created  for  each
       gif(4)  interface  in  the  system.   Each  node  will  attempt  to name itself with the same name as the
       associated interface.  All ng_gif nodes are persistent for as long as the interface itself exists.

       Two hooks are supported: lower and orphans.  The hook name divert may be used as an alias for lower,  and
       is provided for compatibility with ng_ether(4).  In reality the two names represent the same hook.

       The  lower  hook  is  a  connection  to  the raw gif(4) device.  When connected, all incoming packets are
       diverted out this hook.  Writing to this hook results in a raw encapsulated packet being  transmitted  by
       the device.  Normal outgoing packets are not affected by lower being connected.

       The  orphans  hook is equivalent to lower, except that only unrecognized packets (that would otherwise be
       discarded) are written to the hook, and normal incoming traffic is unaffected.  At most  one  of  orphans
       and lower may be connected at any time.

       In all cases, frames are raw packets with the address family of the packet attached to the front.

       When no hooks are connected, packets flow normally upwards and downwards.

HOOKS

       This node type supports the following hooks:

       lower    Connection to the lower device link layer.

       orphans  Like lower, but only receives unrecognized packets.

CONTROL MESSAGES

       This node type supports only the generic control messages.

EXAMPLES

       This  command dumps all unrecognized packets received by the gif0 interface to standard output decoded in
       hex and ASCII:

             nghook -a gif0: orphans

SEE ALSO

       gif(4), netgraph(4), netintro(4), ifconfig(8), ngctl(8), nghook(8)

AUTHORS

       Brooks Davis <brooks@FreeBSD.org>

Debian                                         September 18, 2001                                      NG_GIF(4)