ifconfig.8c

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)ifconfig.8c	3.1	11/24/87
.TH ifconfig 8c
.SH Name
ifconfig \- configure network interface parameters
.SH Syntax
.B /etc/ifconfig
.I interface
[
.I address
[
.I dest_address
] ] [
.I parameters
]
.SH Description
.NXR "ifconfig command" "description"
.NXR "network interface" "configuring parameters"
The
.PN ifconfig
command assigns an address
to a network interface and/or configures
network interface parameters.
You must use
.PN ifconfig
at boot time to define the network address
of each interface present on a machine. You can also use 
it at a later time to redefine an interface's address.  The
.I interface
parameter is a string of the form: name, unit, for example, en0. 
.NXR "ifconfig command" "interface parameter"
The address is either a host name present in the host name data
base, 
.MS hosts 5 ,
or a DARPA Internet address expressed in the Internet standard
dot notation.
.SH Arguments
You can set the following parameters with 
.PN  ifconfig:
.NXR "ifconfig command" "arguments"
.IP up 10
Marks an interface up.
.IP down 10
Marks an interface down.  When an interface is
marked down, the system does not attempt to
transmit messages through that interface. 
.IP trailers 10
Enables the use of a trailer link level encapsulation when
sending.  If a network interface supports
.IR trailers ,
the system, when possible, encapsulates outgoing
messages in a manner that minimizes the number of
memory-to-memory copy operations performed by the receiver.
.sp .5
Although 
.I trailers
is the default on some network interfaces, the use of trailers is 
not recommended;
failures in trailer negotiation can disrupt
network transmissions.
See 
.IR \-trailers .
.IP \-trailers 10
Disables the use of a trailer link level encapsulation.
This is the recommended setting.
.IP promisc 10
Enables the use of the 
.MS packetfilter 4 
in the promiscuous
mode. The promiscuous mode allows the network interface to receive
all the packets off the wire and pass it onto to the
packet filter. 
./"Protocols normally handled by Data Link Interface (DLI)
./"will fail to receive any traffic while the interface is operating
./"in the promiscuous mode. For example, one cannot run
./"DECnet if operating in the promiscuous mode.
.IP \-promisc 10
Disables the promiscuous mode of the packet filter. This is
the default.
.IP \fB+copyall\fR 1i
Sets the interface into copy-all mode
(receives packets sent/received by the kernel-resident protocol
software [for example, IP, ARP, DECnet, LAT] on this host).
.IP \fB\-copyall\fR 1i
Disables copy-all mode. (See 
.MS pfconfig 8c
for more information aboutut the
.PN copyall
flag.)
.IP arp 10
Enables the use of the Address Resolution Protocol in mapping
between network level addresses and link level addresses.  This
is the default.  This is currently implemented for mapping between
DARPA Internet addresses and 10Mb/s Ethernet addresses.
.IP \-arp 10
Disables the use of the Address Resolution Protocol.
.IP debug 10
Enables driver-dependent debugging code. Usually, this turns on
extra console error logging.
.IP \-debug 10
Disables driver dependent debugging code.
.IP netmask 10
Specifies how many bits of the address you wish to
reserve for subdividing Class A and B networks
into sub-networks.  (Inet only).
.IP dstaddr 10
Specifies the correspondent on the other end of
a point to point link.
.IP broadcast 10
Specifies the address you wish to use to
represent broadcasts to the network.
.PP
The
.PN ifconfig
command displays the current configuration for a network interface
when no optional parameters are supplied.
.PP
Only the superuser can modify the configuration of a network interface.
.SH Diagnostics
.NXR "ifconfig command" "diagnostics"
The 
.PN ifconfig 
command returns messages indicating the specified interface does not
exist, the requested address is unknown, the user 
tried to alter an interface's configuration
but is not privileged.
.SH See Also
netstat(1), intro(4n), packetfilter(4), MAKEDEV(8),
pfconfig(8c), pfstat(8),
rc(8)