NAME

ifconfig - 配置網絡接口  

總覽

ifconfig [接口]
ifconfig 接口 [aftype] options | address ...  

描述

ifconfig 用于配置常駐內核的網絡接口。它用于在引導成功時設定網絡接口。此后，只在需要調試及系統調整時才使用。

如沒有給出參數， ifconfig 顯示當前有效接口的狀態。如給定單個 接口 作為參數，它只顯示給出的那個接口的狀態；如果給出一個 -a 參數，它會顯示所有接口的狀態，包括那些停用的接口。否則就對一個接口進行配置。

地址族

如果跟在接口名稱后的第一個參數是它支持地址族的名稱，那么這個地址族被用于翻譯和顯示所有的協議地址。當前支持的地址族包括 inet ( TCP/IP ，缺省)， inet6 ( IPv6 ) ， ax25 ( AMPR 無線分組 )， ddp ( Appletalk 2 代)， ipx ( Novell IPX ) 和 netrom ( AMPR 無線分組)。  

選項

接口 接口名稱。通常是一個后跟單元號的驅動設備名，例如第一個以太接口 eth0 。

up

此選項激活接口。如果給接口聲明了地址，等于隱含聲明了這個選項。

down

此選項使接口驅動設備關閉。

[-]arp

允許或禁止在接口上使用 ARP 協議。

[-]promisc

允許或禁止接口置于混雜模式。如果選用，則接口可以接收網絡上的所有分組。

[-]allmulti

允許或禁止 組播模式（all-multicast） 。 如果選用，則接口可以接收網絡上的所有組播分組。

metric N

將接口度量值設置為整數 N。 (譯注：度量值表示在這個路徑上發送一個分組的成本,就是通過多少個路由）

mtu N

此選項設定接口的最大傳輸單元 MTU。

dstaddr addr

為點到點鏈路(如 PPP )設定一個遠程 IP 地址。此選項現已廢棄；用 pointopoint 選項替換。

netmask addr

為接口設定 IP 網絡掩碼。缺省值通常是 A，B 或 C 類的網絡掩碼 (由接口的 IP 地址推出)，但也可設為其它值。

add addr/prefixlen

為接口加入一個 IPv6 地址。

del addr/prefixlen

為接口刪除一個 IPv6 地址。

tunnel aa.bb.cc.dd

建立一個新的 SIT (在 IPv4 中的 IPv6 )設備，為給定的目的地址建立通道。

irq addr

為接口設定所用的中斷值。并不是所有的設備都能動態更改自己的中斷值。

io_addr addr

為接口設定起始輸入/輸出地址。

mem_start addr

設定接口所用的共享內存起始地址。只有少數設備需要。

media type

設定接口所用的物理端口或介質類型。并不是所有設備都會更改這項值，而且它們支持的類型可能并相同。典型的 type 是 10base2 (細纜以太網)， 10baseT (雙絞線 10Mbps 以太網)， AUI (外部收發單元接口)等等。介質類型為 auto 則用于讓設備自動判斷介質。同樣，并非所有設備都可以這樣工作。

[-]broadcast [addr]

如果給出了地址參數，則可以為接口設定該協議的廣播地址。否則，為接口設置(或清除) IFF_BROADCAST 標志。

[-]pointopoint [addr]

此選項允許接口置為 點到點 模式，這種模式在兩臺主機間建立一條無人可以監聽的直接鏈路。
如果還給出了地址參數，則設定鏈路另一方的協議地址，正如廢棄的 dstaddr 選項的功能。否則，為接口設置(或清除) IFF_POINTOPOINT 標志。

hw class address

如接口驅動程序支持，則設定接口的硬件地址。此選項必須后跟硬件的類型名稱和硬件地址等價的可打印 ASCII 字符。當前支持的硬件類型包括 ether (以太網)， ax25 (AMPR AX.25)， ARCnet 和 netrom (AMPR NET/ROM)。

multicast

為接口設定組播標志。通常無須用此選項因為接口本身會正確設定此標志。

address

為接口分配的 IP 地址。

txqueuelen length

為接口設定傳輸隊列的長度?？梢詾榫哂懈邥r延的低速接口設定較小值以避免在象 telnet 這樣煩人的交互通信時大量高速的傳輸。

注意

從內核版本 2.2 起不再有別名接口的顯式接口統計信息了。打印出的源地址統計信息被同一接口的所有別名地址共享。打印出的源地址統計信息被同一接口的所有別名地址共享。如果你需要每個地址的統計信息，就應該用 ipchains(8) 命令為地址加入顯式的記帳規則。  

相關文件

/proc/net/socket
/proc/net/dev
/proc/net/if_inet6  

BUGS

當顯示 appletalk DDP 和 IPX 地址時不能用此命令進行更改，但可以用這條命令顯示。  

又見

route(8), netstat(8), arp(8), rarp(8), ipchains(8)  

#p#

NAME

ifconfig - configure a network interface  

SYNOPSIS

ifconfig [interface]
ifconfig interface [aftype] options | address ...  

DESCRIPTION

Ifconfig is used to configure the kernel-resident network interfaces. It is used at boot time to set up interfaces as necessary. After that, it is usually only needed when debugging or when system tuning is needed.

If no arguments are given, ifconfig displays the status of the currently active interfaces. If a single interface argument is given, it displays the status of the given interface only; if a single -a argument is given, it displays the status of all interfaces, even those that are down. Otherwise, it configures an interface.

Address Families

If the first argument after the interface name is recognized as the name of a supported address family, that address family is used for decoding and displaying all protocol addresses. Currently supported address families include inet (TCP/IP, default), inet6 (IPv6), ax25 (AMPR Packet Radio), ddp (Appletalk Phase 2), ipx (Novell IPX) and netrom (AMPR Packet radio).  

OPTIONS

interface

The name of the interface. This is usually a driver name followed by a unit number, for example eth0 for the first Ethernet interface.

up

This flag causes the interface to be activated. It is implicitly specified if an address is assigned to the interface.

down

This flag causes the driver for this interface to be shut down.

[-]arp

Enable or disable the use of the ARP protocol on this interface.

[-]promisc

Enable or disable the promiscuous mode of the interface. If selected, all packets on the network will be received by the interface.

[-]allmulti

Enable or disable all-multicast mode. If selected, all multicast packets on the network will be received by the interface.

metric N

This parameter sets the interface metric.

mtu N

This parameter sets the Maximum Transfer Unit (MTU) of an interface.

dstaddr addr

Set the remote IP address for a point-to-point link (such as PPP). This keyword is now obsolete; use the pointopoint keyword instead.

netmask addr

Set the IP network mask for this interface. This value defaults to the usual class A, B or C network mask (as derived from the interface IP address), but it can be set to any value.

add addr/prefixlen

Add an IPv6 address to an interface.

del addr/prefixlen

Remove an IPv6 address from an interface.

tunnel aa.bb.cc.dd

Create a new SIT (IPv6-in-IPv4) device, tunnelling to the given destination.

irq addr

Set the interrupt line used by this device. Not all devices can dynamically change their IRQ setting.

io_addr addr

Set the start address in I/O space for this device.

mem_start addr

Set the start address for shared memory used by this device. Only a few devices need this.

media type

Set the physical port or medium type to be used by the device. Not all devices can change this setting, and those that can vary in what values they support. Typical values for type are 10base2 (thin Ethernet), 10baseT (twisted-pair 10Mbps Ethernet), AUI (external transceiver) and so on. The special medium type of auto can be used to tell the driver to auto-sense the media. Again, not all drivers can do this.

[-]broadcast [addr]

If the address argument is given, set the protocol broadcast address for this interface. Otherwise, set (or clear) the IFF_BROADCAST flag for the interface.

[-]pointopoint [addr]

This keyword enables the point-to-point mode of an interface, meaning that it is a direct link between two machines with nobody else listening on it.
If the address argument is also given, set the protocol address of the other side of the link, just like the obsolete dstaddr keyword does. Otherwise, set or clear the IFF_POINTOPOINT flag for the interface.

hw class address

Set the hardware address of this interface, if the device driver supports this operation. The keyword must be followed by the name of the hardware class and the printable ASCII equivalent of the hardware address. Hardware classes currently supported include ether (Ethernet), ax25 (AMPR AX.25), ARCnet and netrom (AMPR NET/ROM).

multicast

Set the multicast flag on the interface. This should not normally be needed as the drivers set the flag correctly themselves.

address

The IP address to be assigned to this interface.

txqueuelen length

Set the length of the transmit queue of the device. It is useful to set this to small values for slower devices with a high latency (modem links, ISDN) to prevent fast bulk transfers from disturbing interactive traffic like telnet too much.

NOTES

Since kernel release 2.2 there are no explicit interface statistics for alias interfaces anymore. The statistics printed for the original address are shared with all alias addresses on the same device. If you want per-address statistics you should add explicit accounting rules for the address using the ipchains(8) command.

Interrupt problems with Ethernet device drivers fail with EAGAIN. See http://www.scyld.com/expert/irq-conflict.html for more information.  

FILES

/proc/net/socket
/proc/net/dev
/proc/net/if_inet6  

BUGS

While appletalk DDP and IPX addresses will be displayed they cannot be altered by this command.  

SEE ALSO

route(8), netstat(8), arp(8), rarp(8), ipchains(8)