IFCONFIG(8c,C) AIX TCP/IP User s Guide IFCONFIG(8c,C) ------------------------------------------------------------------------------- ifconfig PURPOSE Configures network interface parameters. SYNTAX +----------------+ +---------+ +------------+ ifconfig -- interface --| |--| |--| |--| + address_family + + address + + parameters + DESCRIPTION The ifconfig command is used to assign an address to a network interface or configure network interface parameters. The ifconfig command must be used at boot time to define the network address of each interface present on a machine. This is done by placing the ifconfig command in the /etc/ rc.tcpip or /rc.tcpip.local files. 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, such as tk0. To configure a point-to-point interface (e.g., vctc), use the following format, where interface# is the point-to-point interface name followed by a unit number, such as vctc0: ifconfig interface# address dest_addr For the DARPA Internet family, the address and dest_addr are either a host name data base, /etc/hosts or a DARPA Internet address expressed in the Internet standard dot notation. The ifconfig command serves a similar purpose to the netconfig command. The address family default is DARPA Internet. Currently, AIX does not support other address families. PARAMETERS The following parameters may be set with ifconfig: up Marks 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 is present when previously marked down, the hardware is re-initialized. Processed May 9, 1991 IFCONFIG(8c,C) 1 IFCONFIG(8c,C) AIX TCP/IP User s Guide IFCONFIG(8c,C) down Marks an interface down. When an interface is marked down, the system does not attempt to transmit messages through that interface. If possible, the interface is reset to disable reception as well. This action does not automatically disable routes using the interface. arp token arp ether Enables the use of the Address Resolution Protocol in mapping between network level addresses and link level addresses. arp token selects the Token-Ring address handling scheme. arp ether selects the Ethernet address handling scheme. When using ifconfig to configure a network interface, you must choose either arp ether, arp token, or -arp. There is no default. Note: The syntax for arp has changed since the last version of AIX (1.2). If you have used the arp option of ifconfig, you probably need to change the ifconfig command in either the /etc/rc.tcpip file or the /rc.tcpip.local file . -arp Disables the use of the Address Resolution Protocol. metric 0 ifconfig does not support the metric parameter. However, in some instances, you may be required to give a value n for the metric. In this case, give a value of 0. Any nonzero value you give for n will be converted to 0. debug Enables driver dependent debugging code. Usually, this turns on extra console error logging. -debug Disables driver dependent debugging code. netmask mask (net only) Specifies 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." 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 address (In net only) Specifies 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. Processed May 9, 1991 IFCONFIG(8c,C) 2 IFCONFIG(8c,C) AIX TCP/IP User s Guide IFCONFIG(8c,C) ieee Enables the IEEE 802 protocol on an Ethernet device. -ieee Disables the IEEE 802 protocol on an Ethernet device. 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 receiver. On networks that support the Address Resolution Protocol ("arp"; currently, only 10M bytes Ethernet), this flag indicates that the system should request that only systems use trailers when sending to this host. Similarly, trailer encapsulations will be sent to other hosts that have made such requests currently used by Internet protocols only. -trailers Disables the use of a trailer link level encapsulation. The ifconfig command displays the current configuration for a network interface when no optional parameters are supplied. If a protocol family is specified, ifconfig reports only the details specific to that protocol family. Only the superuser may modify the configuration of a network interface. Note: ifconfig interface address sets the interface up. EXAMPLES Configure the interface "net0" on the host called "host2". # /etc/ifconfig net0 host2 # MESSAGES Messages are provided 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. RELATED INFORMATION In this book: "netstat" "rc.tcpip, rc.tcpip.local" "netconfig" Processed May 9, 1991 IFCONFIG(8c,C) 3