如何使用linux ifconfig命令配置网卡

如何使用linux ifconfig命令配置网卡

来源： 作者：Crystal

About ifconfig

The "ifconfig" command allows the operating system to setup
network interfaces and allow the user to view information about the
configured network interfaces.

Syntax

ifconfig [-L] [-m] interface [create] [address_family] [address[/prefixlength] [dest_address]] [parameters]

ifconfig interface destroy

ifconfig -a [-L] [-d] [-m] [-u] [address_family]

ifconfig -l [-d] [-u] [address_family]

ifconfig [-L] [-d] [-m] [-u] [-C]

address For the DARPA-Internet family, the address is either a
host name present in the host name data base, or a DARPA Internet
address expressed in the Internet standard ``dot notation''.

It is also possible to use the CIDR notation (also known as the
slash notation) to include the netmask. That is, one can specify an
address like 192.168.0.1/16.

addres_family Specify the address family which affects
interpretation of the remaining parameters. Since an interface can
receive transmissions in differing protocols with different naming
schemes, specifying the address family is recommended. The address or
protocol families currently supported are ``inet'', ``inet6'',

dest_address Specify the address of the correspondent on the other end of a point to point link.

interface This parameter is a string of the form ``name unit'', for example, ``en0''.

add Another name for the alias parameter. Introduced for compatibility with BSD/OS.

alias Establish an additional network address for this
interface. This is sometimes useful when changing network numbers, and
one wishes to accept packets addressed to the old interface. If the
address is on the same subnet as the first network address for this
interface, a netmask of 0xffffffff has to be specified.

-alias Remove the network address specified. This would be used
if you incorrectly specified an alias, or it was no longer needed. If
you have incorrectly set an NS address having the side effect of
specifying the host portion, removing all NS addresses will allow you
to respecify the host portion.

anycast (Inet6 only.) Specify that the address configured is an
anycast address. Based on the current specification, only routers may
configure anycast addresses. Anycast address will not be used as source
address of any of outgoing IPv6 packets.

arp Enable the use of the Address Resolution Protocol in mapping
between network level addresses and link level addresses (default).
This is currently implemented for mapping between DARPA Internet
addresses and IEEE 802 48-bit MAC addresses (Ethernet, FDDI, and Token
Ring addresses).

-arp Disable the use of the Address Resolution Protocol

broadcast (Inet only.) Specify the address to use to represent
broadcasts to the network. The default broadcast address is the address
with a host part of all 1's.

debug Enable driver dependent debugging code; usually, this turns on extra console error logging.

-debug Disable driver dependent debugging code.

　　Linux下网卡命名规律：eth0，eth1.第一块以太网卡，第二块。lo为环回接口，它的IP地址固定为127.0.0.1，掩码8位。它代表你的机器本身。
　
　　1、ifconfig是查看网卡的信息。
　
　　ifconfig [Interface]
　
　　Interface是可选项，如果不加此项，则显示系统中所有网卡的信息。如果添加此选项则显示所指定的网卡信息
　
　　例如：ifconfig eth0
　

eth0 Link encap:Ethernet HWaddr 00:0C:29:F3:3B:F2 inet addr:192.168.0.10 Bcast:192.168.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:78 errors:0 dropped:0 overruns:0 frame:0 TX packets:104 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:11679 (11.4 Kb) TX bytes:14077 (13.7 Kb) Interrupt:10 Base address:0x1080

　
　　我们可以看到
　
　　第一行：连接类型：Ethernet（以太网）HWaddr（硬件mac地址）
　
　　第二行：网卡的IP地址、子网、掩码
　
　　第三行：UP（代表网卡开启状态）RUNNING（代表网卡的网线被接上）MULTICAST（支持组播）MTU：1500（最大传输单元）：1500字节
　
　　第四、五行：接收、发送数据包情况统计
　
　　第七行：接收、发送数据字节数统计信息。
　
　　2、ifconfig 配置网卡
　
　　配置网卡的IP地址
　
　　ifconfig eth0 192.168.0.1 netmask 255.255.255.0
　
　　在eth0上配置上192.168.0.1 的IP地址及24位掩码。若想再在eth0上在配置一个192.168.1.1/24 的IP地址怎么办？用下面的命令
　
　　ifconfig eth0：0 192.168.1.1 netmask 255.255.255.0
　
　　这时再用ifconifg命令查看，就可以看到两个网卡的信息了，分别为：eth0和eth0：0.若还想再增加IP，那网卡的命名就接着是：eth0：1、eth0：2……想要几个就填几个。ok！
　

delete Another name for the -alias parameter.
down Mark an interface ``down''. When
an interface is marked ``down'', the system will not attempt to
transmit messages through that interface. If possible, the interface
will be reset to disable reception as well. This action does not
automatically disable routes using the interface.
ether Another name for the lladdr parameter.
lladdr addr Set the link-level address
on an interface. This can be used to e.g. set a new MAC address on an
ethernet interface, though the mechanism used is not ethernet-specific.
The address addr is specified as a series of colon-separated hex
digits. If the interface is already up when this option is used, it
will be briefly brought down and then brought backup again in order to
ensure that the receive filter in the underlying ethernet hardware is
properly reprogrammed.
media type If the driver supports the
media selection system, set the media type of the interface to type.
Some interfaces support the mutually exclusive use of one of several
different physical media connectors. For example, a 10Mb/s Ethernet
interface might support the use of either AUI or twisted pair
connectors. Setting the media type to ``10base5/AUI'' would change the
currently active connector to the AUI port. Setting it to
``10baseT/UTP'' would activate twisted pair. Refer to the interfaces'
driver specific documentation or man page for a complete list of the
available types.
-mediaopt opts If the driver supports
the media selection system, set the specified media options on the
interface. The opts argument is a comma delimited list of options to
apply to the interface. Refer to the interfaces' driver specific man
page for a complete list of available options.
tunnel src_addr dest_addr (IP tunnel
devices only.) Configure the physical source and destination address
for IP tunnel interfaces. The arguments src_addr and dest_addr are
interpreted as the outer source/destination for the encapsulating
IPv4/IPv6 header.
deletetunnel Unconfigure the physical
source and destination address for IP tunnel interfaces previously
configured with tunnel.
create Create the specified network
pseudo-device. If the interface is given without a unit number, try to
create a new device with an arbitrary unit number. If creation of an
arbitrary device is successful, the new device name is printed to
standard output.
destroy Destroy the specified network pseudo-device.

　　配置网卡的硬件地址
　
　　ifconfig eth0 hw ether xx：xx：xx：xx：xx：xx
　
　　就将网卡的硬件地址更改了，此时你就可以骗过局域网内的IP地址邦定了。
　
　　将网卡禁用
　
　　ifconfig eth0 down
　
　　将网卡启用
　
　　ifconfig eth0 up
　
　　ifconfig 命令的功能很强大，还可以设置网卡的MTU，混杂模式等。就不一一介绍了，用时间可以自己研究一下。
　
　　注意：用ifconfig命令配置的网卡信息，在网卡重启后机器重启后，配置就不存在。要想将上述的配置信息永远的存的电脑里，那就要修改网卡的配置文件了。
　

plumb Another name for the create parameter. Included for Solaris compatibility.
unplumb Another name for the destroy parameter. Included for Solaris compatibility.
metric n Set the routing metric of the
interface to n, default 0. The routing metric is used by the routing
protocol. Higher metrics have the effect of making a route less
favorable; metrics are counted as addition hops to the destination
network or host.
mtu n Set the maximum transmission
unit of the interface to n, default is interface specific. The MTU is
used to limit the size of packets that are transmitted on an interface.
Not all interfaces support setting the MTU, and some interfaces have
range restrictions.
netmask mask (Inet only.) Specify how
much of the address to reserve for subdividing networks into
subnetworks. The mask includes the network part of the local address
and the subnet part, which is taken from the host field of the address.
The mask can be specified as a single hexadecimal number with a leading
`0x', with a dot-notation Internet address, or with a pseudo-network
name listed in the network table. The mask contains 1's for the bit
positions in the 32-bit address which are to be used for the network
and subnet parts, and 0's for the host part. The mask should contain at
least the standard network portion, and the subnet field should be
contiguous with the network portion. The netmask can also be specified
in CIDR notation after the address. See the address option above for
more information.
prefixlen len (Inet6 only.) Specify
that len bits are reserved for subdividing networks into sub-networks.
The len must be integer, and for syntactical reason it must be between
0 to 128. It is almost always 64 under the current IPv6 assignment
rule. If the parameter is omitted, 64 is used.
remove Another name for the -alias parameter. Introduced for compatibility with BSD/OS.
link[0-2] Enable special processing of
the link level of the interface. These three options are interface
specific in actual effect, how- ever, they are in general used to
select special modes of operation. An example of this is to enable SLIP
compression, or to select the connector type for some Ethernet cards.
Refer to the man page for the specific driver for more information.
-link[0-2] Disable special processing at the link level with the specified interface.
up Mark an interface ``up''. This may
be used to enable an interface after an ``ifconfig down''. It happens
automatically when setting the first address on an interface. If the
interface was reset when previously marked down, the hardware will be
re-initialized.
Examples
ifconfig eth0
View the network settings on the first Ethernet adapter installed in the computer.
ifconfig -a
Display into on all network interfaces on server, active or inactive.
ifconfig eth0 down
If eth0 exists would take it down causing it cannot send or receive any information.
ifconfig eth0 up
If eth0 exists and in the down state would return it back to the up state allowing to to send and receive information.
ifconfig eth0 192.168.1.102 netmask 255.255.255.0 broadcast 192.168.1.255
Assign eth0 with the above values for IP, netmask and broadcast address.