Интерактивная система просмотра системных руководств (man-ов)
ng_iface (4)
>> ng_iface (4) ( FreeBSD man: Специальные файлы /dev/* )
BSD mandoc
NAME
ng_iface
- interface netgraph node type
SYNOPSIS
#include <netgraph/ng_iface.h>
DESCRIPTION
An
iface
node is both a netgraph node and a system networking interface.
When an
iface
node is created, a new interface appears which is accessible via
ifconfig(8).
Iface
node interfaces are named
ng0ng1
etc.
When a node is shutdown, the corresponding interface is removed
and the interface name becomes available for reuse by future
iface
nodes; new nodes always take the first unused interface.
The node itself is assigned the same name as its interface, unless the name
already exists, in which case the node remains unnamed.
An
iface
node has a single hook corresponding to each supported protocol.
Packets transmitted via the interface flow out the corresponding
protocol-specific hook.
Similarly, packets received on a hook appear on the interface as
packets received into the corresponding protocol stack.
The currently supported protocols are IP, IPv6, AppleTalk, IPX, ATM,
NATM, and NS.
An
iface
node can be configured as a point-to-point interface or a broadcast interface.
The configuration can only be changed when the interface is down.
The default mode is point-to-point.
Iface
nodes support the Berkeley Packet Filter (BPF).
HOOKS
This node type supports the following hooks:
inet
Transmission and reception of IP packets.
inet6
Transmission and reception of IPv6 packets.
atalk
Transmission and reception of AppleTalk packets.
ipx
Transmission and reception of IPX packets.
atm
Transmission and reception of ATM packets.
natm
Transmission and reception of NATM packets.
ns
Transmission and reception of NS packets.
CONTROL MESSAGES
This node type supports the generic control messages, plus the following:
NGM_IFACE_GET_IFNAME
Returns the name of the associated interface as a
NUL -terminatedASCII
string.
Normally this is the same as the name of the node.
NGM_IFACE_GET_IFINDEX
Returns the global index of the associated interface as a 32 bit integer.
NGM_IFACE_POINT2POINT
Set the interface to point-to-point mode.
The interface must not currently be up.
NGM_IFACE_BROADCAST
Set the interface to broadcast mode.
The interface must not currently be up.
NGM_CISCO_GET_IPADDR
This message is defined by the
ng_cisco4
node type; see
ng_cisco4
for a description.
SHUTDOWN
This node shuts down upon receipt of a
NGM_SHUTDOWN
control message.
The associated interface is removed and becomes available
for use by future
iface
nodes.
Unlike most other node types, an
iface
node does
not
go away when all hooks have been disconnected; rather, and explicit
NGM_SHUTDOWN
control message is required.
ALTQ Support
The
interface supports ALTQ bandwidth management feature.
However,
is a special case, since it is not a physical interface with limited bandwidth.
One should not turn ALTQ on
if the latter corresponds to some tunneled connection, e.g. PPPoE or PPTP.
In this case, ALTQ should be configured on the interface that is used to
transmit the encapsulated packets.
In case when your graph ends up with some kind of serial line, either
synchronous or modem, the
is the right place to turn ALTQ on.
