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ifconfig(8)

NAME

ifconfig - Configures or displays network interface parameters

SYNOPSIS

For the AF_INET address family, use the following syntax: /usr/sbin/ifconfig interface_id [address_family] [address[/bitmask] [dest_address]] [parameters] For the AF_INET6 address family, use the following syntax: /usr/sbin/ifconfig interface_id address_family [[ip6prefix] address[/bitmask] [dest_address]] [parameters] For displaying interface information, use the following syntaxes: /usr/sbin/ifconfig -a [-d] [-u] [-v] [address_family] /usr/sbin/ifconfig -l [-d] [-u] [-v] [address_family] /usr/sbin/ifconfig [-v] interface-id [address_family] The ifconfig command assigns and displays an address to a network interface, and configures network interface parameters.

OPTIONS

-a Displays information about all interfaces that are configured on a system. -d Displays information about interfaces that are down only. -l Displays interface names only that are configured on a system. -u Displays information about interfaces that are up only. -v Displays verbose information about interfaces, such as hardware addresses and IPv6 timers.

DESCRIPTION

You use the ifconfig command at boot time to define the network address of each interface. You can also use the ifconfig command at other times to display all interfaces that are configured on a system, to redefine the address of an interface, or to set other operating parameters. Note If you want to redefine the address or the netmask of an interface, use the SysMan Menu utility. Otherwise, any daemons currently running will use the old address and netmask, and will fail. The SysMan Menu utility makes the necessary changes and restarts the network services. The ifconfig command can modify most of the operating parameters associated with network interfaces, including some low-level parameters, such as the speed (10, 100, or 1000 Mb/s) and mode (half-duplex or full-duplex) parameters. However, to set other low-level parameters, such as the media type (AUI, BNC, UTP, or Fiber) or IEEE 802.3u autonegotiation, you must use the lan_config command or possibly a console firmware command. See lan_config(8) for more information about changing these low-level parameters, and viewing their current values. Any user can query the status of a network interface; only the superuser can modify the configuration of network interfaces. You specify an interface with the ifconfig interface_id syntax. (See your hardware documentation for information on obtaining an interface ID.) If you specify only an interface_id, the ifconfig command displays the current configuration for the specified network interface only. If a protocol family is specified by the address_family parameter, ifconfig reports only the configuration details specific to that protocol family. The following table lists valid values for address_family: Address Family Value AF_INET inet AF_INET6 inet6 When changing an interface configuration, if the address family is not AF_INET, you must specify an address family, which may alter the interpretation of any parameters that follow. You must specify an address family because an interface can receive transmissions in different protocols, each of which may require a separate naming scheme. The address argument is the network address of the interface being configured. For the AF_INET address family, the address argument is either a hostname or an Internet address in the standard dotted-decimal notation with or without the optional Classless Inter-Domain Routing (CIDR) bitmask (/bitmask). If using the bitmask argument, do not use the netmask parameter. For the AF_INET6 address family, the address argument is either a hostname or the 128-bit Internet Protocol Version 6 (IPv6) address, as follows: x:x:x:x:x:x:x:x In this format, each x is the hexadecimal value of a 16-bit piece of the address. An IPv6 address typically consists of a 64-bit prefix followed by a 64-bit interface identifier. See the Network Administration: Connections manual for more information on IPv6 addresses. The ip6prefix argument, when configuring an address on the interface, specifies that the address argument is an IPv6 prefix and that the interface identifier is to be appended to it to create a 128-bit IPv6 address. The interface identifier uniquely identifies an interface on a subnet, and is typically the interface's link-layer address. According to RFC 2373, most prefixes are required to have 64-bit interface identifiers. For 48- bit MAC addresses, the interface identifier is created by inserting the hexadecimal values of 0xFF and 0xFE in the middle of the address and inverting the universal/local bit (bit 7) in the resulting 64-bit address. For example, the 48-bit MAC address 0:0:f8:23:10:f3 becomes the 64-bit interface identifier 2:0:f8:ff:fe:23:10:f3. The destination address (dest_address) argument specifies the address of the correspondent on the remote end of a point-to-point link. Parameters abort Closes all TCP connections associated with a network address. Use this parameter when removing aliases or deleting network addresses. This prevents users from experiencing a hanging connection when the network address is deleted. add interface-id [,interface-id] Creates or modifies a set of redundant adapters (NetRAIN). The ifconfig interface-id parameter must be a NetRAIN virtual interface name of the form nrx, where x is the unit number (Valid unit numbers are 0 to nr_maxdev-1. See sys_attrs_netrain(5) for a description of nr_maxdev and other netrain subsystem attributes. You can adjust this limit by using dxkerneltuner or the sysconfig command). If the NetRAIN virtual interface does not exist, it is created. You can also specify multiple interface-id parameters when creating a NetRAIN set. The interface-id specified must represent adapters of the same type connected to the same LAN segment. You can also modify an existing NetRAIN set by adding one interface-id at a time. The interface-id specified must represent an adapter of the same type and connected to the same LAN segment as other adapters in the NetRAIN set. See the Network Administration: Connections manual for complete information on configuring a NetRAIN interface. alias alias_address[/bitmask] [AF_INET only] Establishes an additional network address for this interface. This can be useful when changing network numbers and you want to continue to accept packets addressed to the old interface. This alias is in effect only until the system is rebooted. To establish this alias automatically each time the system is booted, edit the inet.local file and add the ifconfig alias entries to it. If you do not specify a bitmask or netmask with an alias address, the default netmask is based on the alias address's network class. If you are using the optional bitmask argument, do not use the netmask argument. This parameter has the following restrictions: · You can specify only one alias alias_address parameter for each ifconfig command line. · You cannot specify an alias and a primary address on the same command line. -alias alias_address [AF_INET only] Removes the network address specified. This can be used either if you incorrectly specified an alias or if an alias is no longer needed. The -alias parameter functions in the same manner as the delete parameter. aliaslist address_list[/bitmask] [AF_INET only] Establishes a range of additional network addresses for this interface. The range can be either a comma-separated list or a hyphenated list, and is inclusive. You can also specify the optional CIDR bitmask (/bitmask) argument at the end of the list. Do not use a comma-separated list and a hyphenated list for a range. See the "Examples" section for valid examples of the aliaslist parameter. If you do not specify a netmask with the alias list, the default netmask is based on the alias address's network class. -aliaslist [AF_INET only] Removes a range of network addresses for this interface. This can be useful when deleting network numbers and you want to keep the primary interface address. The alias list rules are the same as for the aliaslist parameter. allmulti Enables the reception of all multicast packets. allmulti Disables the reception of all multicast packets. arp Enables the use of the Address Resolution Protocol (ARP) in mapping between network-level IPv4 addresses and link-level addresses. This parameter is on by default. -arp Disables the use of the ARP. Use of this parameter is not recommended. See arp(8) for more information. broadcast broad_address Specifies the address to use to represent broadcasts to the network. The default broadcast address is the address with a host part consisting of all 1s (ones). Note that the computation of the host part is dependent on netmask (see the description of the netmask parameter). debug Enables driver-dependent debug code. This might turn on extra console error logging. (See your hardware documentation for further information.) -debug Disables driver-dependent debug code. delete [net_address] Removes the network address specified. This would be used if you incorrectly specified an alias, or if 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. Note Be careful when you use this parameter. If you either specify the network address before the delete parameter or specify no network address after the delete parameter, all IPv4 and IPv6 network addresses for the interface and IPv6 routes are deleted. IPv4 routes are not deleted. down Marks an interface as not working (down), which keeps the system from trying to transmit messages through that interface. If possible, the ifconfig command also resets the interface to disable reception of messages. Routes that use the interface, however, are not automatically disabled. filter Enables access filtering on the interface. Reads the /etc/ifaccess.conf file and constructs an interface access filter based on entries in the file. Interface access filtering provides a mechanism for detecting and preventing IP spoofing attacks. (See CERT Advisory CA-95:01). The source addresses of IP input packets are checked against access filter entries; packets receive the action associated with the first matching entry. The following actions are valid: permit, deny, or denylog; the final filter entry is a default permit all. See ifaccess.conf(4) for more information. Use the netstat(1) command to display the current access filters for the interface. -filter Disables access filtering on the interface. ip6dadtries value [AF_INET6 only] Specifies the number of consecutive Neighbor Solicitation messages that your system transmits while it performs Duplicate Address Detection on a tentative address. ip6hoplimit hops [AF_INET6 only] Sets the default number of hops to be included in transmitted unicast IP packets. ip6interfaceid id [AF_INET6 only] Overrides that default interface ID, which depends on the underlying link type (for example, Ethernet, FDDI, and Token Ring), and specifies id as the interface ID. For example, if your system has the Ethernet hardware address 08-00-2b-2a-1e-d3, the following command generates the inet6 link-local address fe80::a00:2bff:fe2a:1ed3 for the interface: ifconfig ln0 ipv6 On the same system, the following command generates the inet6 interface ID abcd:1234 for the interface: ifconfig ln0 ip6interfaceid ::abcd:1234 ipv6 ip6mtu mtu_value [AF_INET6 only] Alters the maximum transfer unit (MTU) for messages that your system transmits on the link. ip6nonud [AF_INET6 only] Disables Neighbor Unreachability Detection (NUD) on the interface. ip6reachabletime time [AF_INET6 only] Sets the time, in milliseconds, that your system considers a neighbor is reachable after your system receives a reachability confirmation message. ip6retranstimer value [AF_INET6 only] Sets the time interval, in milliseconds, between Neighbor Solicitation messages to a neighbor. ipdst Specifies an Internet host willing to receive IP packets encapsulating packets bound for a remote network. ipmtu mtu_value [AF_INET only] Alters the size of the maximum transfer unit (MTU) for messages that your system transmits. It might be necessary to reduce the MTU size so that bridges connecting token rings can transfer frames without error. ipv6 [AF_INET6 only] Initializes IPv6-related data structures and assigns an IPv6 link-local address to the interface. -ipv6 [AF_INET6 only] Removes any IPv6 configuration associated with the interface, including all IPv6 addresses and IPv6 routes through the interface. This command is equivalent to the ifconfig interface inet6 delete command. metric number Sets the routing metric, or number of hops, for the interface to the value of number. The default value is 0 (zero) if number is not specified, indicating that both hosts are on the same network. The routing metric is used by the routed and gated daemons, with higher metrics indicating that the route is less favorable. multinet [AF_INET only] Enables the use of multiple subnets on the interface. This is required when an IP alias address is configured on an interface and it is in a different subnet than the primary IP address of the interface. -multinet [AF_INET only] Disables the use of multiple subnets on the interface. netmask mask [AF_INET only] Specifies how much of the address to reserve for subdividing networks into sub-networks. This parameter can only be used with an address family of inet. Do not use this parameter if you are specifying the CIDR mask (/bitmask) with the address argument, alias parameter, or aliaslist parameter. The mask variable includes both 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 beginning with 0x, in the standard Internet dotted-decimal notation, or beginning with a name. The mask contains 1s (ones) for the bit positions in the 32-bit address that are reserved for the network and subnet parts, and 0s (zeros) for the bit positions that specify the host. The mask should contain at least the standard network portion. The default netmask is based on the address parameter's network class. nrtimers t1, t2 Sets two NetRAIN interface timing parameters. The t1 parameter specifies the time period, in seconds, that the traffic monitor thread delays between reads of the interface counters when the network is running normally. If there is no change in the received byte count for t1 seconds, the traffic monitor thread issues a yellow alert. The recommended t1 value is 4. The t2 parameter specifies the traffic-free time period, in seconds, that must pass before the traffic monitor thread declares the interface dead. The recommended t2 value is 10 for Ethernet interfaces and 16 for Asynchronous Transfer Mode (ATM) LAN Emulation (LANE) interfaces. You can specify decimal values for both the t1 and t2 parameters (for example, 1.5 or 0.8). If you do this, the values are validated similarly to the nr_timeout_t and nr_timeout_o kernel attributes. See sys_attrs_netrain(5) for more information on minimum and maximum NetRAIN timer values. NetRAIN uses Network Interface Failure Finder (NIFF) to monitor the NetRAIN interfaces. See nifftmt(7) for more information. physaddr mac-address Associates a virtual Media Access Control (MAC) address (mac-address) with an IP network address. You must specify an alias address with this command. The system sends an ARP "whohas" request containing the physical address followed by an ARP "whohas" request containing the virtual MAC address. This association is in effect only until the system is rebooted. To establish this association automatically each time the system is booted, edit the inet.local file and add the ifconfig physaddr entries to it. -physaddr mac-address Disassociates the virtual MAC address (mac-address) from an IP network address. promisc Sets the interface into promiscuous mode. This directs the network interface to receive all packets off the network, rather than just those packets directed to the host. -promisc Disables the promiscuous mode of the interface. This is the default. remove [interface-id] Removes one or all interfaces attached to a NetRAIN interface. If you do not specify an interface-id, all interfaces are removed from the NetRAIN set, their default hardware addresses are restored, and the UP option is cleared. The hardware address of the NetRAIN virtual interface is set to 00:00:00:00:00:00 and its UP option is cleared. If you specify only one interface-id and it is a member of the NetRAIN interface (nrx), the interface is removed from the NetRAIN set. If interface-id is also the active interface and there are other interfaces in the set, the active interface is switched to another interface in the set. If there is only one interface in the NetRAIN set, the following two commands are equivalent: ifconfig nrx remove ifconfig nrx remove interface-id You can also reconfigure the NetRAIN virtual interface by using the add command. speed value Sets the speed at which the token ring adapter transmits and receives on the token ring network to value. The value can be either 4 for a ring speed of 4Mbs or 16 for 16Mbs. The adapter speed must match the signal speed of the token ring. This parameter also determines the speed (regular, fast, or gigabit Ethernet) and half- or full-duplex mode operation on the interface when that interface is using the twisted-pair port as follows: Value Configuration 10 10 Mbps Ethernet half-duplex 20 10 Mbps Ethernet full-duplex 100 100 Mbps Ethernet half-duplex 200 100 Mbps Ethernet full-duplex 1000 1000 Mbps Ethernet half-duplex 2000 1000 Mbps Ethernet full-duplex After the interface is online, you can use the ifconfig up and down options to change the speed value dynamically. Stop adapter transmission with down and set the speed in the same command line. Then specify up without a speed value to restart the adapter. switch Force a NetRAIN interface to failover to another interface in the NetRAIN set. If the ifconfig interface-id specified is the NetRAIN virtual interface, the next available interface in the set becomes active. If the ifconfig interface-id is a member of the NetRAIN set, the interface-id specified becomes the active member. If the interface-id specified is not operational, the switch command has no effect. trailers Requests the use of a trailer link-level encapsulation when sending messages. If a network interface supports trailers, the system will, when possible, encapsulate outgoing messages in a manner that minimizes the number of memory-memory copy operations performed by the receiver. On networks that support the Address Resolution Protocol (see arp), this option indicates that the system should request that other 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. This is the default. trustgrp group Sets the trust group identifier for the interface. Trust group identifiers are passed from the kernel to the screend daemon, and indicate the color of the interface on which a packet was received and the color of the interface to which a packet is intended, as indicated by the kernel routing tables. The group can be one of the primary colors in the visible spectrum (for example, red, orange, yellow, green, blue, indigo, and violet). The screend daemon can optionally use trust group information to make packet screening decisions. By default, the trust group identifier is unknown, meaning any interface. Only application gateways for firewall services use trust group identifiers. up Marks an interface as working (up). This parameter is used automatically when setting the first address for an interface, or can be used to enable an interface after an ifconfig down command. If the interface was reset when previously marked with the parameter down (see the following section for a description of this parameter), the hardware will be reinitialized. vphysaddr mac-address Associates a virtual Media Access Control (MAC) address (mac-address) with an IP network address. You must specify an alias address with this command. The system sends both initial ARP "whohas" requests containing the virtual MAC address. This association is in effect only until the system is rebooted. To establish this association automatically each time the system is booted, edit the inet.local file and add the ifconfig vphysaddr entries to it. Use the -physaddr mac-address option to remove the virtual MAC address association. Display options When you issue the ifconfig command for an interface you might see any of the following options: ALLMULTI The interface will receive all multicast packets. BROADCAST The interface supports broadcast packets. This is a read-only option that is set by the driver. DEBUG Driver-dependent debugging is enabled. LOOPBACK The interface is a loopback mode. Packets transmitted on this interface will be looped back in the driver and not be transmitted out on the network. MULTICAST The interface supports multicast packets. This is a read-only option that is set by the driver, does not mean that a multicast address is configured for the interface. MULTINET Multiple networks are configured on the interface. This means that an IP alias is in a different subnet than the primary IP address. NOARP The interface is not using address resolution protocol (ARP). It will neither transmit nor respond to ARP requests. NOCHECKSUM The interface does not perform checksums on transmitted or received packets. Use this only on very reliable network media. NOTRAILERS Trailer link-level encapsulation for transmitted packets is disabled. OACTIVE The interface is actively transmitting packets. This is a read-only option that is set by the driver. PFCOPYALL All packets transmitted on this interface are copied and passed to the packet filter program. POINTOPOINT The interface is point-to-point link. This is a read-only option that is set by the driver. PROMISC The interface is in promiscuous mode. All packets received are copied and passed to the packet filter program. QUORUMLOSS UP interface marked DOWN due to cluster quorum loss. RESERVED The interface is reserved for use by another virtual interface. Members of a NetRAIN set are reserved by the NetRAIN virtual interface. Members of a link aggregation group are reserved by the LAG virtual interface. Interfaces that are enabled for VLAN are reserved by the VLAN virtual interface. RUNNING The driver has allocated resources for the interface, and is ready to transmit and receive packets. This is a read-only option that is set by the driver. It is not applicable to loopback devices, for example, lo0. SIMPLEX The interface cannot hear its own transmissions. This is a read-only option that is set by the driver. TAGGING The interface is currently in IEEE 802.1q tagging support mode. UP The interface is up. This option is turned on when an address has been configured on the interface. VAR_MTU The interface supports variable Maximum Transmission Unit (MTU) sizes. The is a read-only option that is set by the driver. In addition, you might see NetRAIN, VLAN, and link aggregation virtual interface relationships, if any.

EXAMPLES

1. To query the status of serial line interface sl0, enter: $ ifconfig sl0 sl0: options=10<POINTOPOINT> 2. To configure the local loopback interface, enter: # ifconfig lo0 inet 127.0.0.1 up Only a user with superuser authority can modify the configuration of a network interface. 3. To configure a ee0 interface, enter: # ifconfig ee0 212.232.32.1/22 The broadcast address is 212.232.35.255 as the 22-bit mask specifies four Class C networks. 4. To configure the token ring interface for a 4 Mbps token ring with a netmask of 255.255.255.0 in CIDR format, enter: # ifconfig tra0 130.180.4.1/24 speed 4 5. To stop the token ring interface and start it for a 16 Mbps token ring, enter: # ifconfig tra0 down # ifconfig tra0 speed 16 up 6. To configure IPv6 on a ee0 interface, enter: # ifconfig ee0 ipv6 up 7. To create a NetRAIN set nr1 with the Ethernet interfaces ee0 and ee2 as the set members, enter: # ifconfig nr1 add ee0,ee2 To set the IP address of this interface to 18.240.32.40, enter: # ifconfig nr1 inet 18.240.32.40 To view this set, enter: # ifconfig nr1 nr1: options=c63<UP,BROADCAST,NOTRAILERS,RUNNING,MULTICAST,SIMPLEX> NetRAIN Attached Interfaces: ( ee0 ee2 ) Active Interface: ( ee0 ) inet 18.240.32.40 netmask ffffff00 broadcast 18.240.32.255 ipmtu 1500 To add interfaces ee1 and ee3 to this set, enter: # ifconfig nr1 add ee1 # ifconfig nr1 add ee3 To remove the interface ee0 from the NetRAIN set created in the previous example, enter: # ifconfig nr1 remove ee0 To disassemble the entire NetRAIN set created in the previous example, enter: # ifconfig nr1 remove 8. To add alias 132.50.40.35 with a netmask of 255.255.255.0 in CIDR format to interface tu0, enter: # ifconfig tu0 alias 132.50.40.35/24 9. To add network addresses 40 through 50, inclusive, to subnets 18.240.32, 18.240.33, 18.240.34, 18.240.35, and 18.240.36 with a netmask of 255.255.255.0 in CIDR format to the tu0 interface, enter: # ifconfig tu0 aliaslist 132.240.32-36.40-50/24 10. To add network addresses 40 through 50, inclusive, to subnets 18.240.32, 18.240.64, and 18.240.96 with a netmask of 255.255.255.0 in CIDR format to the tu0 interface, enter: # ifconfig tu0 aliaslist 132.240.32,64,96.40-50/24 11. To stop Ethernet interface tu0, delete all addresses associated with the interface, and close all TCP connections, enter: # ifconfig tu0 down delete abort 145.92.16.1: aborting 7 tcp connection(s) 12. To delete the alias address 145.92.16.2 on interface tu0 and close all TCP connections, enter: # ifconfig tu0 -alias 145.92.16.2 abort 145.92.16.2: aborting 2 tcp connection(s) 13. To create an IPv6 address for prefix AB:CD:CE:AB, enter: # ifconfig tu0 inet6 ip6prefix AB:CD:CE:AB::/64 14. To associate MAC address aa:01:81:43:02:11 with the alias address 145.92.16.2, enter: # ifconfig tu0 alias 145.92.16.2 physaddr aa:01:81:43:02:11 15. To disassociate MAC address aa:01:81:43:02:11 from the alias address 145.92.16.2, enter: # ifconfig tu0 -alias 145.92.16.2 -physaddr aa:01:81:43:02:11 16. To display the names of the interfaces on the system only, enter: # ifconfig -l fta0 lo0 tu0 tu1 17. To display the hardware and IP address of interface tu0, enter: # ifconfig -v tu0 tu0: options=c63<UP,BROADCAST,NOTRAILERS,RUNNING,MULTICAST,SIMPLEX> HWaddr 8:0:2b:9e:14:a2 inet 192.140.34.16 netmask ffffff00 broadcast 192.140.34.255 ipmtu 1500

ERRORS

· Broadcast can only be used with address, alias or aliaslist parameters. Explanation The broadcast option was specified without an address parameter. · Cannot set primary and alias addresses, or multiple alias addresses. Explanation You specified more than one alias alias_address parameter on the same ifconfig command line or you specified an alias and an interface-id on the same command line. · Invalid bitmask Explanation The bitmask specified is not in the range of 1 to 32, inclusive. · Netmask cannot be used with bitmask. Explanation The netmask option was specified together with a CIDR bitmask. · Netmask can only be used with address, alias or aliaslist parameters. Explanation The netmask option was specified without an address parameter. · No such device: nrx Explanation You specified the switch option and no other physical interfaces that are part of the NetRAIN set are UP; it is impossible to switch interfaces.

FILES

/usr/sbin/ifconfig Specifies the command path /etc/ifaccess.conf Interface access filtering configuration file /etc/inet.local File to invoke local network commands

RELATED INFORMATION

Commands: lan_config(8), netstat(1), niffconfig(8), pfconfig(8), sysconfig(8) gated(8), routed(8), screend(8) Files: ifaccess.conf(4), inet.local(4) Interfaces: nifftmt(7), nr(7) System Attributes: sys_attrs_netrain(5) Network Administration: Connections

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