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IFCONFIG(8) OpenBSD System Manager's Manual IFCONFIG(8) NAME ifconfig - configure network interface parameters SYNOPSIS ifconfig interface address_family [address [dest_address]] [parameters] ifconfig tunnel-interface tunnel src_address dest_address ifconfig tunnel-interface deletetunnel ifconfig vlan-interface vlan vlan-tag vlandev parent-interface ifconfig interface [address_family] ifconfig -m interface [address_family] ifconfig [-a | -am] [address_family] ifconfig [-A | -Am] [address_family] DESCRIPTION The ifconfig utility is used to assign an address to a network interface and/or configure network interface parameters. ifconfig must be used at boot-time to define the network address of each interface present on a machine; it may also be used at a later time to redefine an interface's address or other operating parameters. To configure a bridge interface, use the brconfig(8) program instead. The operands are as follows: address For the DARPA-Internet family, the address is either a host name present in the host name data base, hosts(5), or a DARPA Internet address expressed in the Internet standard ``dot notation''. For the Xerox Network Systems(tm) and Internetwork Packet Exchange families, addresses are net:a.b.c.d.e.f, where net is the as- signed network number (in decimal), and each of the six bytes of the host number, a through f, are specified in hexadecimal. The host number may be omitted on Ethernet interfaces, which use the hardware physical address, and on interfaces other than the first. For the ISO family, addresses are specified as a long hexadecimal string, as in the Xerox family. However, two consec- utive dots imply a zero byte, and the dots are optional, if the user wishes to (carefully) count out long strings of digits in network byte order. AppleTalk (LLAP) addresses are specified as nn.na (Network Number.Node Address). Node addresses are divided into 2 classes: User Node IDs and Server Node IDs. 1-127($01-$7F) are for User Node IDs while 128-254($80-$FE) are used for Server Node IDs. Node 0($00) is not allowed (unknown) while Node 255($FF) is reserved for the AppleTalk broadcast Hardware address (broadcast ID). address_family Specifies the address family which affects interpretation of the remaining parameters. Since an interface can receive transmis- sions in differing protocols with different naming schemes, spec- ifying the address family is recommended. The address or proto- col families currently supported are ``inet'', ``inet6'', ``atalk'', ``iso'', ``ipx'', and ``ns''. interface The interface parameter is a string of the form ``name unit'', for example, ``en0''. The following parameters may be set with ifconfig: alias Establish an additional network address for this inter- face. This is sometimes useful when changing network numbers, and one wishes to accept packets addressed to the old interface. -alias Remove the specified network address alias. arp Enable the use of the Address Resolution Protocol in map- ping between network level addresses and link level ad- dresses (default). This is currently implemented for mapping between DARPA Internet addresses and Ethernet ad- dresses. -arp Disable the use of the Address Resolution Protocol. anycast (inet6 only) Set the IPv6 anycast address bit. -anycast (inet6 only) Clear the IPv6 anycast address bit. broadcast addr (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. delete 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. dest_address Specify the address of the correspondent on the other end of a point to point link. down Mark an interface ``down''. When an interface is marked ``down'', the system will not attempt to transmit mes- sages through that interface. If possible, the interface will be reset to disable reception as well. This action automatically disables routes using the interface. tunnel src_address dest_address Set the source and destination tunnel addresses on a tun- nel interface, including gif(4). Packets routed to this interface will be encapsulated in IPv4 or IPv6, depending on the source and destination address families. Both ad- dresses must be of the same family. deletetunnel Removes the source and destination tunnel addresses, con- figured onto a tunnel interface. ipdst This is used to specify an Internet host who is willing to receive ip packets encapsulating NS packets bound for a remote network. An apparent point to point link is constructed, and the address specified will be taken as the NS address and network of the destination. IP encap- sulation of CLNP packets is done differently. link[0-2] Enable special processing of the link level of the inter- face. These three options are interface specific in ac- tual effect; however, they are in general used to select special modes of operation. An example of this is to en- able 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. media type Set the media type of the interface to type. Some inter- faces support the mutually exclusive use of one of sever- al 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'' or ``AUI'' would change the currently ac- tive connector to the AUI port. Setting it to ``10baseT'' or ``UTP'' would activate twisted pair. Re- fer to the interfaces' driver specific man page for a complete list of the available types, or use # ifconfig -m interface for a listing of choices. mediaopt opts Set the specified media options on the interface. opts is a comma delimited list of options to apply to the in- terface. Refer to the interfaces' driver specific man page for a complete list of available options, or use ifconfig -m interface for a listing of choices. -mediaopt opts Disable the specified media options on the interface. mtu value Set the MTU for this device to the given value. Cloned routes will inherit this value as a default. instance minst Set the media instance to minst. This is useful for de- vices which have multiple physical layer interfaces (PHYs). Setting the instance on such devices may not be strictly required by the network interface driver as the driver may take care of this automatically; see the driv- er's manual page for more information. vlan vlan_tag If the interface is a vlan pseudo interface, set the vlan tag value to vlan_tag. This value is a 12-bit number which is used to create an 802.1Q vlan header for packets sent from the vlan interface. Note that vlan and vlandev must both be set at the same time. vlandev iface If the interface is a vlan pseudo device, associate phys- ical interface iface with it. Packets transmitted through the vlan interface will be diverted to the specified physical interface iface with 802.1Q vlan encapsulation. Packets with 802.1Q encapsulation received by the parent interface with the correct vlan tag will be diverted to the associated vlan pseudo-interface. The vlan interface is assigned a copy of the parent interface's flags and the parent's ethernet address. The vlandev and vlan must both be set at the same time. If the vlan interface al- ready has a physical interface associated with it, this command will fail. To change the association to another physical interface, the existing association must be cleared first. Note: if the link0 flag is set on the vlan interface, the vlan pseudo interface's behavior changes: the link0 tells the vlan interface that the parent interface supports in- sertion and extraction of vlan tags on its own (usually in firmware) and that it should pass packets to and from the parent unaltered. -vlandev If the driver is a vlan pseudo device, disassociate the physical interface from it. This breaks the link between the vlan interface and its parent, clears its vlan tag, flags and its link address and shuts the interface down. metric n Set the routing metric of the interface to n, default 0. The routing metric is used by the routing protocol (routed(8)). Higher metrics have the effect of making a route less favorable; metrics are counted as addition hops to the destination network or host. netmask mask (inet, inet6 and iso) Specify how much of the address to reserve for subdividing networks into sub-networks. 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 hex- adecimal number with a leading 0x, with a dot-notation Internet address, or with a pseudo-network name listed in the network table networks(5). 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 contigu- ous with the network portion. nsellength n (ISO only) This specifies a trailing number of bytes for a received NSAP used for local identification, the re- maining leading part of which is taken to be the NET (Network Entity Title). The default value is 1, which is conformant to US GOSIP. When an ISO address is set in an ifconfig command, it is really the NSAP which is being specified. For example, in US GOSIP, 20 hex digits should be specified in the ISO NSAP to be assigned to the interface. There is some evidence that a number differ- ent from 1 may be useful for AFI 37 type addresses. nwid id (IEEE 802.11 devices only) Configure network ID for IEEE 802.11-based wireless network interfaces. The id can ei- ther be any text string up to 32 characters in length, or a series of hexadecimal digits up to 64 digits. The emp- ty string allows the interface to connect to any avail- able access points. nwkey key (IEEE 802.11 devices only) Enable WEP encryption for IEEE 802.11-based wireless network interfaces using the speci- fied key. The key can either be a string, a series of hexadecimal digits (preceded by `0x'), or a set of keys of the form n:k1,k2,k3,k4, where n specifies which of the keys will be used for transmitted packets, and the four keys, k1 through k4, are configured as WEP keys. If a set of keys is specified, a comma (`,') within the key must be escaped with a backslash. Note that if multiple keys are used, their order must be the same within the network. For IEEE 802.11 wireless networks, the length of each key is restricted to 40 bits, i.e. a 5-character string or 10 hexadecimal digits. WaveLAN/IEEE Gold and newer Prism cards will also accept a 104 bit (13 charac- ter) key. nwkey persist (IEEE 802.11 devices only) Enable WEP encryption for IEEE 802.11-based wireless network interfaces with the persis- tent key stored in the network card. nwkey persist:key (IEEE 802.11 devices only) Write key to the persistent memory of the network card, and enable WEP encryption for IEEE 802.11-based wireless network interfaces using that key. -nwkey (IEEE 802.11 devices only) Disable WEP encryption for IEEE 802.11-based wireless network interfaces. phase The argument following this specifies the version (phase) of the AppleTalk network attached to the interface. Val- ues of 1 or 2 are permitted. pltime n (inet6 only) Set preferred lifetime for the address. powersave (IEEE 802.11 devices only) Enable 802.11 power saving mode. -powersave (IEEE 802.11 devices only) Disable 802.11 power saving mode. powersavesleep duration (IEEE 802.11 devices only) Set the receiver sleep dura- tion (in milliseconds) for 802.11 power saving mode. prefixlen n (inet and inet6 only) Effect is similar to netmask, but you can specify prefix length by digits. range Under AppleTalk, set the interface to respond to a netrange of the form startnet-endnet. AppleTalk uses this scheme instead of netmasks though OpenBSD implements it internally as a set of netmasks. tentative (inet6 only) Set the IPv6 tentative address bit. -tentative (inet6 only) Clear the IPv6 tentative address bit. eui64 (inet6 only) Fill interface index (lowermost 64bit of an IPv6 address) automatically. trailers Request the use of a ``trailer'' link level encapsulation when sending (default). If a network interface supports trailers, the system will, when possible, encapsulate outgoing messages in a manner which minimizes the number of memory to memory copy operations performed by the re- ceiver. On networks that support the Address Resolution Protocol (see arp(4); currently, only Ethernet), this flag indicates that the system should request that other systems use trailers when sending to this host. Similar- ly, trailer encapsulations will be sent to other hosts that have made such requests. Currently used by Internet protocols only. -trailers Disable the use of a ``trailer'' link level encapsula- tion. up Mark an interface ``up''. This may be used to enable an interface after an ``ifconfig down''. It happens auto- matically when setting the first address on an interface. If the interface was reset when previously marked down, the hardware will be re-initialized. vltime n (inet6 only) Set valid lifetime for the address. 802.2 802.2tr 802.3 snap EtherII Set the ipx(3) frame type to be either 802.2, 802.2tr, 802.3, snap or Ethernet II. ifconfig displays the current configuration for a network interface when no optional parameters are supplied. If a protocol family is specified, ifconfig will report only the details specific to that protocol family. Using -a causes ifconfig to print information on all interfaces. The protocol family may be specified as well. Additionally, if -am is used, interface media information is printed. If -A is used, it causes full interface alias information for each inter- face to be displayed. If -Am is used, interface media information is printed for all interfaces as well. If -m followed by an interface name is specified, then the media informa- tion for that interface will be printed. Only the superuser may modify the configuration of a network interface. EXAMPLES # ifconfig fxp0 inet 192.168.1.10 netmask 255.255.255.0 Assign the inet(4) address of 192.168.1.10 with a network mask of 255.255.255.0 to interface fxp0. # ifconfig fxp0 ipx 12625920 Assign the ipx(3) address of 12625920 specified in decimal to interface fxp0. # ifconfig fxp0 atalk 39108.128 range 39107-39109 phase Cm0 Assign the AppleTalk network 39108 and server node 128 with a network range of 39107-39109 to interface fxp0 on a phase 2 Ap- pleTalk network. # ifconfig xl0 media 10baseT Configure the xl0 interface to use 10baseT. # ifconfig xl0 media 100baseTX mediaopt full-duplex Configure the xl0 interface to use 100baseTX, full duplex. # ifconfig vlan0 192.168.254.1 vlan 4 vlandev fxp0 Configure the vlan0 interface for IP address 192.168.254.1, vlan tag 4, and vlan parent device fxp0. DIAGNOSTICS Messages indicating the specified interface does not exist, the requested address is unknown, or the user is not privileged and tried to alter an interface's configuration. SEE ALSO netstat(1), ifmedia(4), netintro(4), hostname.if(5), brconfig(8), rc(8), routed(8) HISTORY The ifconfig command appeared in 4.2BSD. OpenBSD 3.4 September 3, 1998 6
NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | DIAGNOSTICS | SEE ALSO | HISTORY
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