ifconfig(1M)

NAME

ifconfig − configure network interface parameters

SYNOPSIS

/etc/ifconfig interface [ address [ dest_address ] ] [ parameters ]

DESCRIPTION

ifconfig is used to assign an address to a network interface and/or configure network interface parameters. On intelligent networking controllers, ifconfig is also used to download and initialize the controller firmware. 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. The interface parameter is a string of the form “name unit”, e.g. “ex0”. Address is either a host name present in the host name data base, hosts(4C), or a DARPA Internet address expressed in the Internet standard “dot notation”. If dest_addr is present, it specifies the address of the correspondent on the other end of a point-to-point link. Interface must be a point-to-point link interface for this to be valid. Dest_addr is specified in the same manner as address above.

The parameters listed below may be set with ifconfig. Those which are accepted only for selected controller types are noted in the descriptive text.

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 specified for an intelligent networking controller, or if the interface was reset when previously marked down, the hardware will be re-initialized. Intelligent networking controllers are reloaded and reconfigured whenever this parameter is present.

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.

−trailers Disable the use of a “trailer” link level encapsulation. Note that CX/UX does not support “trailer” encapsulations.

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 10Mb/s Ethernet addresses.

−arp Disable the use of the Address Resolution Protocol.

ip802.2 Causes Internet messages to be sent using IEEE 802.2/802.3 formatting. Message formatting corresponds to IEEE standards and RFC 1042. Currently available only on host-based Ethernet controllers. IEEE 802.2 formatting is standard on FDDI networks.

−ip802.2 Disables IEEE 802.2/802.3 formatting for Internet messages. Message formats are returned to standard Ethernet format. Currently available only on host-based Ethernet controllers. Will not disable IEEE 802.2 formatting on FDDI networks.

metric n Set the routing metric of the interface to n, default 0. The routing metric is used by the routing protocol (routed(1M)). Higher metrics have the effect of making a route less favorable; metrics are counted as addition hops to the destination network or host.

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

−debug Disable driver dependent debugging code.

noredirect Disable the effect of ICMP route redirect messages. This can be used to disable route redirect attacks.

−noredirect Allow ICMP route redirect messages. This is the default action for an interface.

netmask mask 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 hexadecimal number with a leading 0x, with a dot-notation Internet address, or with a pseudo-network name listed in the network table networks(4C). 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.

broadcast addr Specify the address to use to represent broadcasts to the network. Addr is expressed in the Internet standard “dot notation”. The default broadcast address is the address with a host part of all ones. In previous versions of CX/UX, the broadcast address was the address with a host part of all zeros. Use this option to change the broadcast address to the address with a host part of all zeros if there are machines on your network that use old-style broadcast addresses. Old-style broadcast addresses are still recognized for compatibility.

firmware file Specifies an alternate firmware boot file name to be used with an intelligent networking controller. The default filename if this parameter is not specified is /usr/lib/fddiwcs for FDDI controllers and /usr/lib/ethwcs for Ethernet controllers.

Ifconfig displays the current configuration for a network interface when no optional parameters are supplied.

Only the super-user may modify the configuration of a network interface.

SECURITY FEATURES

The following security features are available with LAN/SX on host-based networking controllers. Additional parameters may be used to enable Discretionary Access Control (DAC) on a per interface basis. DAC may be applied to both source or destination addresses. These options apply only to the interface specified. The default is for host DAC to be disabled.

hostdac Enable the checking of host DAC.

−hostdac Disable the checking of host DAC.

srcdac Enable checking of all source addresses for host DAC.

−srcdac Disable checking of all source addresses for host DAC.

destdac Enable checking of all destination addresses for host DAC.

−destdac Disable checking of all destination addresses for host DAC.

forwsrcdac Enable checking of all source address from hosts whose packets are to be forwarded through this interface.

−forwsrcdac Disable checking of all source address from hosts whose packets are to be forwarded through this interface.

forwdestdac Enable checking of all destination address that are to be forwarded through this interface.

−forwdestdac Disable checking of all destination address that are to be forwarded through this interface.

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.

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