ifconfig(1M) (man pages section 1M: System Administration Commands)

man pages section 1M: System Administration Commands

ifconfig(1M)

Name

ifconfig– configure network interface parameters

Synopsis

ifconfig interface [address_family] [address [/prefix_length] 
 [dest_address]] [addif address [/prefix_length]]
 [removeif address [/prefix_length]] [arp | -arp]
 [auth_algs authentication algorithm] [encr_algs encryption algorithm]
 [encr_auth_algs authentication algorithm] [auto-revarp]
 [broadcast address] [deprecated | -deprecated]
 [preferred | -preferred] [destination dest_address]
 [ether [address]] [failover | -failover] [group
 [name | ""]] [index if_index] [ipmp] [metric n] [modlist]
 [modinsert mod_name@pos] [modremove mod_name@pos]
 [mtu n] [netmask mask] [plumb] [unplumb] [private
 | -private] [nud | -nud] [set [address] [/netmask]]
 [standby | -standby] [subnet subnet_address] [tdst 
 tunnel_dest_address] [token address/prefix_length]
 [tsrc tunnel_src_address] [trailers | -trailers]
 [up] [down] [usesrc [name | none]] [xmit | -xmit]
 [encaplimit n | -encaplimit] [thoplimit n] [router
 | -router] [zone zonename | -zone | -all-zones]

ifconfig [address_family] interface {auto-dhcp | dhcp} [primary]
 [wait seconds] drop | extend | inform | ping
 | release | start | status

Description

The command ifconfig is used to assign an address to a network interface and to 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; it may also be used at a later time to redefine an interface's address or other operating parameters. If no option is specified, ifconfig displays the current configuration for a network interface. If an address family is specified, ifconfig reports only the details specific to that address family. Only privileged users may modify the configuration of a network interface. Options appearing within braces ({ }) indicate that one of the options must be specified.

DHCP Configuration

The forms of ifconfig that use the auto-dhcp or dhcp arguments are used to control the Dynamic Host Configuration Protocol (“DHCP”) configuration of the interface. In this mode, ifconfig is used to control operation of dhcpagent(1M), the DHCP client daemon. Once an interface is placed under DHCP control by using the start operand, ifconfig should not, in normal operation, be used to modify the address or characteristics of the interface. If the address of an interface under DHCP is changed, dhcpagent will remove the interface from its control.

Options

The following options are supported:

addif address

Create the next unused logical interface on the specified physical interface.

all-zones

Make the interface available to every shared-IP zone on the system. The appropriate zone to which to deliver data is determined using the tnzonecfg database. This option is available only if the system is configured with the Solaris Trusted Extensions feature.

The tnzonecfg database is described in the tnzonecfg(4) man page, which is part of the Solaris Trusted Extensions Reference Manual.

anycast

Marks the logical interface as an anycast address by setting the ANYCAST flag. See “INTERFACE FLAGS,” below, for more information on anycast.

-anycast

Marks the logical interface as not an anycast address by clearing the ANYCAST flag.

arp

Enable the use of the Address Resolution Protocol (“ARP”) in mapping between network level addresses and link level addresses (default). This is currently implemented for mapping between IPv4 addresses and MAC addresses.

-arp

Disable the use of the ARP on a physical interface. ARP cannot be disabled on an IPMP IP interface.

auth_algs authentication algorithm

For a tunnel, enable IPsec AH with the authentication algorithm specified. The algorithm can be either a number or an algorithm name, including any to express no preference in algorithm. All IPsec tunnel properties must be specified on the same command line. To disable tunnel security, specify an auth_alg of none.

It is now preferable to use the ipsecconf(1M) command when configuring a tunnel's security properties. If ipsecconf was used to set a tunnel's security properties, this keyword will not affect the tunnel.

auto-dhcp

Use DHCP to automatically acquire an address for this interface. This option has a completely equivalent alias called dhcp.

For IPv6, the interface specified must be the zeroth logical interface (the physical interface name), which has the link-local address.

primary: Defines the interface as the primary. The interface is defined as the preferred one for the delivery of client-wide configuration data. Only one interface can be the primary at any given time. If another interface is subsequently selected as the primary, it replaces the previous one. Nominating an interface as the primary one will not have much significance once the client work station has booted, as many applications will already have started and been configured with data read from the previous primary interface.
wait seconds: The ifconfig command will wait until the operation either completes or for the interval specified, whichever is the sooner. If no wait interval is given, and the operation is one that cannot complete immediately, ifconfig will wait 30 seconds for the requested operation to complete. The symbolic value forever may be used as well, with obvious meaning.
drop: Remove the specified interface from DHCP control without notifying the DHCP server, and record the current lease for later use. Additionally, for IPv4, set the IP address to zero. For IPv6, unplumb all logical interfaces plumbed by dhcpagent.
extend: Attempt to extend the lease on the interface's IP address. This is not required, as the agent will automatically extend the lease well before it expires.
inform: Obtain network configuration parameters from DHCP without obtaining a lease on IP addresses. This is useful in situations where an IP address is obtained through mechanisms other than DHCP.
ping: Check whether the interface given is under DHCP control, which means that the interface is managed by the DHCP agent and is working properly. An exit status of 0 means success.
release: Relinquish the IP addresses on the interface by notifying the server and discard the current lease. For IPv4, set the IP address to zero. For IPv6, all logical interfaces plumbed by dhcpagent are unplumbed.
start: Start DHCP on the interface.
status: Display the DHCP configuration status of the interface.

auto-revarp

Use the Reverse Address Resolution Protocol (RARP) to automatically acquire an address for this interface. This will fail if the interface does not support RARP; for example, IPoIB (IP over InfiniBand), and on IPv6 interfaces.

broadcast address

For IPv4 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. A “+” (plus sign) given for the broadcast value causes the broadcast address to be reset to a default appropriate for the (possibly new) address and netmask. The arguments of ifconfig are interpreted left to right. Therefore

example% ifconfig -a netmask + broadcast +

and

example% ifconfig -a broadcast + netmask +

may result in different values being assigned for the broadcast addresses of the interfaces.

deprecated

Marks the logical interface as deprecated. An address associated with a deprecated interface will not be used as source address for outbound packets unless either there are no other addresses available on the interface or the application has bound to this address explicitly. The status display shows DEPRECATED as part of flags. See INTERFACE FLAGS for information on the flags supported by ifconfig.

-deprecated

Marks a logical interface as not deprecated. An address associated with such an interface could be used as a source address for outbound packets.

preferred

Marks the logical interface as preferred. This option is only valid for IPv6 addresses. Addresses assigned to preferred logical interfaces are preferred as source addresses over all other addresses configured on the system, unless the address is of an inappropriate scope relative to the destination address. Preferred addresses are used as source addresses regardless of which physical interface they are assigned to. For example, you can configure a preferred source address on the loopback interface and advertise reachability of this address by using a routing protocol.

-preferred

Marks the logical interface as not preferred.

destination dest_address

Set the destination address for a point-to point interface.

dhcp

This option is an alias for option auto-dhcp

down

Mark a logical interface as “down”. (That is, turn off the IFF_UP bit.) When a logical interface is marked “down,” the system does not attempt to use the address assigned to that interface as a source address for outbound packets and will not recognize inbound packets destined to that address as being addressed to this host. Additionally, when all logical interfaces on a given physical interface are “down,” the physical interface itself is disabled.

When a logical interface is down, all routes that specify that interface as the output (using the -ifp option in the route(1M) command or RTA_IFP in a route(7P) socket) are removed from the forwarding table. Routes marked with RTF_STATIC are returned to the table if the interface is brought back up, while routes not marked with RTF_STATIC are simply deleted.

When all logical interfaces that could possibly be used to reach a particular gateway address are brought down (specified without the interface option as in the previous paragraph), the affected gateway routes are treated as though they had the RTF_BLACKHOLE flag set. All matching packets are discarded because the gateway is unreachable.

encaplimit n

Set the tunnel encapsulation limit for the interface to n. This option applies to IPv4–in-IPv6 and IPv6–in-IPv6 tunnels only, and it simply modifies the encaplimit link property of the underlying IPv6 tunnel link (see dladm(1M)). The tunnel encapsulation limit controls how many more tunnels a packet can enter before it leaves any tunnel, that is, the tunnel nesting level.

This option is obsolete, superseded by the dladm(1M) encaplimit link property.

-encaplimit

Disable generation of the tunnel encapsulation limit. This option applies only to IPv4–in-IPv6 and IPv6–in-IPv6 tunnels. This simply sets the encaplimit link property of the underlying IPv6 tunnel link to 0 (see dladm(1M) encaplimit).

This option is obsolete, superseded by the dladm(1M) encaplimit link property.

encr_auth_algs authentication algorithm

For a tunnel, enable IPsec ESP with the authentication algorithm specified. It can be either a number or an algorithm name, including any or none, to indicate no algorithm preference. If an ESP encryption algorithm is specified but the authentication algorithm is not, the default value for the ESP authentication algorithm will be any.

encr_algs encryption algorithm

For a tunnel, enable IPsec ESP with the encryption algorithm specified. It can be either a number or an algorithm name. Note that all IPsec tunnel properties must be specified on the same command line. To disable tunnel security, specify the value of encr_alg as none. If an ESP authentication algorithm is specified, but the encryption algorithm is not, the default value for the ESP encryption will be null.

ether [ address ]

If no address is given and the user is root or has sufficient privileges to open the underlying datalink, then display the current Ethernet address information.

Otherwise, if the user is root or has sufficient privileges, set the Ethernet address of the interfaces to address. The address is an Ethernet address represented as x:x:x:x:x:x where x is a hexadecimal number between 0 and FF. Similarly, for the IPoIB (IP over InfiniBand) interfaces, the address will be 20 bytes of colon-separated hex numbers between 0 and FF.

Some, though not all, Ethernet interface cards have their own addresses. To use cards that do not have their own addresses, refer to section 3.2.3(4) of the IEEE 802.3 specification for a definition of the locally administered address space. Note that all IP interfaces in an IPMP group must have unique hardware addresses; see in.mpathd(1M).

-failover

Set NOFAILOVER on the logical interface. This makes the associated address available for use by in.mpathd to perform probe-based failure detection for the associated physical IP interface. As a side effect, DEPRECATED will also be set on the logical interface. This operation is not permitted on an IPMP IP interface.

failover

Clear NOFAILOVER on the logical interface. This is the default. These logical interfaces are subject to migration when brought up (see IP MULTIPATHING GROUPS).

group [ name |""]

When applied to a physical interface, it places the interface into the named group. If the group does not exist, it will be created, along with one or more IPMP IP interfaces (for IPv4, IPv6, or both). Any UP addresses that are not also marked NOFAILOVER are subject to migration to the IPMP IP interface (see IP MULTIPATHING GROUPS). Specifying a group name of "" removes the physical IP interface from the group.

When applied to a physical IPMP IP interface, it renames the IPMP group to have the new name. If the name already exists, or a name of "" is specified, it fails. Renaming IPMP groups is discouraged. Instead, the IPMP IP interface should be given a meaningful name when it is created by means of the ipmp subcommand, which the system will also use as the IPMP group name.

index n

Change the interface index for the interface. The value of n must be an interface index (if_index) that is not used on another interface. if_index will be a non-zero positive number that uniquely identifies the network interface on the system.

ipmp

Create an IPMP IP interface with the specified name. An interface must be separately created for use by IPv4 and IPv6. The address_family parameter controls whether the command applies to IPv4 or IPv6 (IPv4 if unspecified). All IPMP IP interfaces have the IPMP flag set.

metric n

Set the routing metric of the interface to n; if no value is specified, the default is 0. The routing metric is used by the routing protocol. Higher metrics have the effect of making a route less favorable. Metrics are counted as addition hops to the destination network or host.

modinsert mod_name@pos

Insert a module with name mod_name to the stream of the device at position pos. The position is relative to the stream head. Position 0 means directly under stream head.

Based upon the example in the modlist option, use the following command to insert a module with name ipqos under the ip module and above the firewall module:

example% ifconfig eri0 modinsert ipqos@2

A subsequent listing of all the modules in the stream of the device follows:

example% ifconfig eri0 modlist
0 arp
1 ip
2 ipqos
3 firewall 
4 eri

modlist

List all the modules in the stream of the device.

The following example lists all the modules in the stream of the device:

example% ifconfig eri0 modlist
0 arp
1 ip
2 firewall
4 eri

modremove mod_name@pos

Remove a module with name mod_name from the stream of the device at position pos. The position is relative to the stream head.

Based upon the example in the modinsert option, use the following command to remove the firewall module from the stream after inserting the ipqos module:

example% ifconfig eri0 modremove firewall@3

A subsequent listing of all the modules in the stream of the device follows:

example% ifconfig eri0 modlist
0 arp
1 ip
2 ipqos
3 eri

Note that the core IP stack modules, for example, ip and tun modules, cannot be removed.

mtu n

Set the maximum transmission unit of the interface to n. For many types of networks, the mtu has an upper limit, for example, 1500 for Ethernet. This option sets the FIXEDMTU flag on the affected interface.

netmask mask

For IPv4 only. Specify how much of the address to reserve for subdividing networks into subnetworks. 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 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. The mask can be specified in one of four ways:

with a single hexadecimal number with a leading 0x,
with a dot-notation address,
with a “+” (plus sign) address, or
with a pseudo host name/pseudo network name found in the network database networks(4).

If a “+” (plus sign) is given for the netmask value, the mask is looked up in the netmasks(4) database. This lookup finds the longest matching netmask in the database by starting with the interface's IPv4 address as the key and iteratively masking off more and more low order bits of the address. This iterative lookup ensures that the netmasks(4) database can be used to specify the netmasks when variable length subnetmasks are used within a network number.

If a pseudo host name/pseudo network name is supplied as the netmask value, netmask data may be located in the hosts or networks database. Names are looked up by first using gethostbyname(3NSL). If not found there, the names are looked up in getnetbyname(3SOCKET). These interfaces may in turn use nsswitch.conf(4) to determine what data store(s) to use to fetch the actual value.

For both inet and inet6, the same information conveyed by mask can be specified as a prefix_length attached to the address parameter.

nud

Enables the neighbor unreachability detection mechanism on a point-to-point physical interface.

-nud

Disables the neighbor unreachability detection mechanism on a point-to-point physical interface.

plumb

For a physical IP interface, open the datalink associated with the physical interface name and set up the plumbing needed for IP to use the datalink. When used with a logical interface name, this command is used to create a specific named logical interface on an existing physical IP interface.

An interface must be separately plumbed for IPv4 and IPv6 according to the address_family parameter (IPv4 if unspecified). Before an interface has been plumbed, it will not be shown by ifconfig -a.

Note that IPMP IP interfaces are not tied to a specific datalink and are instead created with the ipmp subcommand.

private

Tells the in.routed routing daemon that a specified logical interface should not be advertised.

-private

Specify unadvertised interfaces.

removeif address

Remove the logical interface on the physical interface specified that matches the address specified.

router

Enable IP forwarding on the interface. When enabled, the interface is marked ROUTER, and IP packets can be forwarded to and from the interface. Enabling ROUTER on any IP interface in an IPMP group enables it on all IP interfaces in that IPMP group.

-router

Disable IP forwarding on the interface. IP packets are not forwarded to and from the interface. Disabling ROUTER on any IP interface in an IPMP group disables it on all IP interfaces in that IPMP group.

set

Set the address, prefix_length or both, for a logical interface.

standby

Mark the physical IP interface as a STANDBY interface. If an interface is marked STANDBY and is part of an IPMP group, the interface will not be used for data traffic unless another interface in the IPMP group becomes unusable. When a STANDBY interface is functional but not being used for data traffic, it will also be marked INACTIVE. This operation is not permitted on an IPMP IP interface.

-standby

Clear STANDBY on the interface. This is the default.

subnet

Set the subnet address for an interface.

tdst tunnel_dest_address

Set the destination address of a tunnel. The address should not be the same as the dest_address of the tunnel, because no packets leave the system over such a tunnel.

This option is obsolete, superseded by the dladm(1M) create-iptun and modify-iptun subcommands.

thoplimit n

Set the hop limit for a tunnel interface. The hop limit value is used as the TTL in the IPv4 header for the IPv6–in-IPv4 and IPv4–in-IPv4 tunnels. For IPv6–in-IPv6 and IPv4–in-IPv6 tunnels, the hop limit value is used as the hop limit in the IPv6 header. This option simply modifies the hoplimit link property of the underlying IP tunnel link (see dladm(1M)).

This option is obsolete, superseded by the dladm(1M) hoplimit link property.

token address/prefix_length

Set the IPv6 token of an interface to be used for address autoconfiguration.

example% ifconfig eri0 inet6 token ::1/64

trailers

This flag previously caused a nonstandard encapsulation of IPv4 packets on certain link levels. Drivers supplied with this release no longer use this flag. It is provided for compatibility, but is ignored.

-trailers

Disable the use of a “trailer” link level encapsulation.

tsrc tunnel_src_address

Set the source address of a tunnel. This is the source address on an outer encapsulating IP header. It must be an address of another interface already configured using ifconfig.

This option is obsolete, superseded by the dladm(1M) create-iptun and modify-iptun subcommands.

unplumb

For a physical or IPMP interface, remove all associated logical IP interfaces and tear down any plumbing needed for IP to use the interface. For an IPMP IP interface, this command will fail if the group is not empty. For a logical interface, the logical interface is removed.

An interface must be separately unplumbed for IPv4 and IPv6 according to the address_family parameter (IPv4 if unspecified). Upon success, the interface name will no longer appear in the output of ifconfig -a.

up

Mark a logical interface UP. As a result, the IP module will accept packets destined to the associated address (unless the address is zero), along with any associated multicast and broadcast IP addresses. Similarly, the IP module will allow packets to be sent with the associated address as a source address. At least one logical interface must be UP for the associated physical interface to send or receive packets

usesrc [ name | none ]

Specify a physical interface to be used for source address selection. If the keyword none is used, then any previous selection is cleared.

When an application does not choose a non-zero source address using bind(3SOCKET), the system will select an appropriate source address based on the outbound interface and the address selection rules (see ipaddrsel(1M)).

When usesrc is specified and the specified interface is selected in the forwarding table for output, the system looks first to the specified physical interface and its associated logical interfaces when selecting a source address. If no usable address is listed in the forwarding table, the ordinary selection rules apply. For example, if you enter:

# ifconfig eri0 usesrc vni0

...and vni0 has address 10.0.0.1 assigned to it, the system will prefer 10.0.0.1 as the source address for any packets originated by local connections that are sent through eri0. Further examples are provided in the EXAMPLES section.

While you can specify any physical interface (or even loopback), be aware that you can also specify the virtual IP interface (see vni(7d)). The virtual IP interface is not associated with any physical hardware and is thus immune to hardware failures. You can specify any number of physical interfaces to use the source address hosted on a single virtual interface. This simplifies the configuration of routing-based multipathing. If one of the physical interfaces were to fail, communication would continue through one of the remaining, functioning physical interfaces. This scenario assumes that the reachability of the address hosted on the virtual interface is advertised in some manner, for example, through a routing protocol.

Because the ifconfig preferred option is applied to all interfaces, it is coarser-grained than the usesrc option. It will be overridden by usesrc and setsrc (route subcommand), in that order.

IPMP and the usesrc option are mutually exclusive. That is, if an interface is part of an IPMP group or marked STANDBY, then it cannot be specified by means of usesrc, and vice-versa.

xmit

Enable a logical interface to transmit packets. This is the default behavior when the logical interface is up.

-xmit

Disable transmission of packets on an interface. The interface will continue to receive packets.

zone zonename

Place the logical interface in zone zonename. The named zone must be active in the kernel in the ready or running state. The interface is unplumbed when the zone is halted or rebooted. The zone must be configure to be an shared-IP zone. zonecfg(1M) is used to assign network interface names to exclusive-IP zones.

-zone

Place IP interface in the global zone. This is the default.

Operands

The interface operand, as well as address parameters that affect it, are described below.

interface

A string of one of the following forms:

name physical-unit, for example, eri0 or ce1
name physical-unit:logical-unit, for example, eri0:1
ip.tunN, ip6.tunN, or ip6to4.tunN for implicit IP tunnel links

If the interface name starts with a dash (-), it is interpreted as a set of options which specify a set of interfaces. In such a case, -a must be part of the options and any of the additional options below can be added in any order. If one of these interface names is given, the commands following it are applied to all of the interfaces that match.

-a: Apply the command to all interfaces of the specified address family. If no address family is supplied, either on the command line or by means of /etc/default/inet_type, then all address families will be selected.
-d: Apply the commands to all “down” interfaces in the system.
-D: Apply the commands to all interfaces not under DHCP (Dynamic Host Configuration Protocol) control.
-u: Apply the commands to all “up” interfaces in the system.
-Z: Apply the commands to all interfaces in the user's zone.
-4: Apply the commands to all IPv4 interfaces.
-6: Apply the commands to all IPv6 interfaces.

address_family

The address family is specified by the address_family parameter. The ifconfig command currently supports the following families: inet and inet6. If no address family is specified, the default is inet.

ifconfig honors the DEFAULT_IP setting in the /etc/default/inet_type file when it displays interface information . If DEFAULT_IP is set to IP_VERSION4, then ifconfig will omit information that relates to IPv6 interfaces. However, when you explicitly specify an address family (inet or inet6) on the ifconfig command line, the command line overrides the DEFAULT_IP settings.

address

For the IPv4 family (inet), the address is either a host name present in the host name data base (see hosts(4)) or in the Network Information Service (NIS) map hosts, or an IPv4 address expressed in the Internet standard “dot notation”.

For the IPv6 family (inet6), the address is either a host name present in the host name data base (see hosts(4)) or in the Network Information Service (NIS) map ipnode, or an IPv6 address expressed in the Internet standard colon-separated hexadecimal format represented as x:x:x:x:x:x:x:x where x is a hexadecimal number between 0 and FFFF.

prefix_length

For the IPv4 and IPv6 families (inet and inet6), the prefix_length is a number between 0 and the number of bits in the address. For inet, the number of bits in the address is 32; for inet6, the number of bits in the address is 128. The prefix_length denotes the number of leading set bits in the netmask.

dest_address

If the dest_address parameter is supplied in addition to the address parameter, it specifies the address of the correspondent on the other end of a point-to-point link.

tunnel_dest_address

An address that is or will be reachable through an interface other than the tunnel being configured. This tells the tunnel where to send the tunneled packets. This address must not be the same as the interface destination address being configured.

tunnel_src_address

An address that is attached to an already configured interface that has been configured “up” with ifconfig.

INTERFACE FLAGS

The ifconfig command supports the following interface flags. The term “address” in this context refers to a logical interface, for example, eri0:0, while “interface” refers to the physical interface, for example, eri0.

ADDRCONF

The address is from stateless addrconf. The stateless mechanism allows a host to generate its own address using a combination of information advertised by routers and locally available information. Routers advertise prefixes that identify the subnet associated with the link, while the host generates an “interface identifier” that uniquely identifies an interface in a subnet. In the absence of information from routers, a host can generate link-local addresses. This flag is specific to IPv6.

ANYCAST

Indicates an anycast address. An anycast address identifies the nearest member of a group of systems that provides a particular type of service. An anycast address is assigned to a group of systems. Packets are delivered to the nearest group member identified by the anycast address instead of being delivered to all members of the group.

BROADCAST

This broadcast address is valid. This flag and POINTTOPOINT are mutually exclusive

CoS

This interface supports some form of Class of Service (CoS) marking. An example is the 802.1D user priority marking supported on VLAN interfaces. For IPMP IP interfaces, this will only be set if all interfaces in the group have CoS set.

Note that this flag is only set on interfaces over VLAN links and over Ethernet links that have their dladm(1M) tagmode link property set to normal.

DEPRECATED

This address is deprecated. This address will not be used as a source address for outbound packets unless there are no other addresses on this interface or an application has explicitly bound to this address. An IPv6 deprecated address is part of the standard mechanism for renumbering in IPv6 and will eventually be deleted when not used. For both IPv4 and IPv6, DEPRECATED is also set on all NOFAILOVER addresses, though this may change in a future release.

DHCPRUNNING

The logical interface's address is managed by dhcpagent(1M). For IPv6, this will also be set on the zeroth logical interface if DHCPv6 has been started on the interface; see in.ndpd(1M).

DUPLICATE

The logical interface has been disabled because the IP address configured on the interface is a duplicate. Some other node on the network is using this address. If the address was configured by DHCP or is temporary, the system will choose another automatically, if possible. Otherwise, the system will attempt to recover this address periodically and the interface will recover when the conflict has been removed from the network. Changing the address or netmask, or setting the logical interface to up will restart duplicate detection. Setting the interface to down terminates recovery and removes the DUPLICATE flag.

FAILED

The in.mpathd daemon has determined that the interface has failed. FAILED interfaces will not be used to send or receive IP data traffic. If this is set on a physical IP interface in an IPMP group, IP data traffic will continue to flow over other usable IP interfaces in the IPMP group. If this is set on an IPMP IP interface, the entire group has failed and no data traffic can be sent or received over any interfaces in that group.

FIXEDMTU

The MTU has been set using the -mtu option. This flag is read-only. Interfaces that have this flag set have a fixed MTU value that is unaffected by dynamic MTU changes that can occur when drivers notify IP of link MTU changes.

INACTIVE

The physical interface is functioning but is not used to send or receive data traffic according to administrative policy. This flag is initially set by the standby subcommand and is subsequently controlled by in.mpathd. It also set when FAILBACK=no mode is enabled (see in.mpathd(1M)) to indicate that the IP interface has repaired but is not being used.

IPMP

Indicates that this is an IPMP IP interface.

LOOPBACK

Indicates that this is the loopback interface.

MULTI_BCAST

Indicates that the broadcast address is used for multicast on this interface.

MULTICAST

The interface supports multicast. IP assumes that any interface that supports hardware broadcast, or that is a point-to-point link, will support multicast.

NOARP

There is no address resolution protocol (ARP) for this interface that corresponds to all interfaces for a device without a broadcast address. This flag is specific to IPv4.

NOFAILOVER

The address associated with this logical interface is available to in.mpathd for probe-based failure detection of the associated physical IP interface.

NOLOCAL

The interface has no address , just an on-link subnet.

NONUD

NUD is disabled on this interface. NUD (neighbor unreachability detection) is used by a node to track the reachability state of its neighbors, to which the node actively sends packets, and to perform any recovery if a neighbor is detected to be unreachable. This flag is specific to IPv6.

NORTEXCH

The interface does not exchange routing information. For RIP-2, routing packets are not sent over this interface. Additionally, messages that appear to come over this interface receive no response. The subnet or address of this interface is not included in advertisements over other interfaces to other routers.

NOXMIT

Indicates that the address does not transmit packets. RIP-2 also does not advertise this address.

OFFLINE

The interface is offline and thus cannot send or receive IP data traffic. This is only set on IP interfaces in an IPMP group. See if_mpadm(1M) and cfgadm(1M).

POINTOPOINT

Indicates that the address is a point-to-point link. This flag and BROADCAST are mutually exclusive

PREFERRED

This address is a preferred IPv6 source address. This address will be used as a source address for IPv6 communication with all IPv6 destinations, unless another address on the system is of more appropriate scope. The DEPRECATED flag takes precedence over the PREFERRED flag.

PRIVATE

Indicates that this address is not advertised. For RIP-2, this interface is used to send advertisements. However, neither the subnet nor this address are included in advertisements to other routers.

PROMISC

A read-only flag indicating that an interface is in promiscuous mode. All addresses associated with an interface in promiscuous mode will display (in response to ifconfig -a, for example) the PROMISC flag.

ROUTER

Indicates that IP packets can be forwarded to and from the interface.

RUNNING

Indicates that the required resources for an interface are allocated. For some interfaces this also indicates that the link is up. For IPMP IP interfaces, RUNNING is set as long as one IP interface in the group is active.

STANDBY

Indicates that this physical interface will not be used for data traffic unless another interface in the IPMP group becomes unusable. The INACTIVE and FAILED flags indicate whether it is actively being used.

TEMPORARY

Indicates that this is a temporary IPv6 address as defined in RFC 3041.

UNNUMBERED

This flag is set when the local IP address on the link matches the local address of some other link in the system

UP

Indicates that the logical interface (and the associated physical interface) is up. The IP module will accept packets destined to UP addresses (unless the address is zero), along with any associated multicast and broadcast IP addresses. Similarly, the IP module will allow packets to be sent with an UP address as a source address.

VIRTUAL

Indicates that the physical interface has no underlying hardware. It is not possible to transmit or receive packets through a virtual interface. These interfaces are useful for configuring local addresses that can be used on multiple interfaces. (See also the usesrc option.)

LOGICAL INTERFACES

Solaris TCP/IP allows multiple logical interfaces to be associated with a physical network interface. This allows a single machine to be assigned multiple IP addresses, even though it may have only one network interface. Physical network interfaces have names of the form driver-name physical-unit-number, while logical interfaces have names of the form driver-name physical-unit-number:logical-unit-number. A physical interface is configured into the system using the plumb command. For example:

example% ifconfig eri0 plumb

Once a physical interface has been “plumbed”, logical interfaces associated with the physical interface can be configured by separate -plumb or -addif options to the ifconfig command.

example% ifconfig eri0:1 plumb

allocates a specific logical interface associated with the physical interface eri0. The command

example% ifconfig eri0 addif 192.168.200.1/24 up

allocates the next available logical unit number on the eri0 physical interface and assigns an address and prefix_length.

A logical interface can be configured with parameters ( address,prefix_length, and so on) different from the physical interface with which it is associated. Logical interfaces that are associated with the same physical interface can be given different parameters as well. Each logical interface must be associated with an existing and “up” physical interface. So, for example, the logical interface eri0:1 can only be configured after the physical interface eri0 has been plumbed.

To delete a logical interface, use the unplumb or removeif options. For example,

example% ifconfig eri0:1 down unplumb

will delete the logical interface eri0:1.

IP MULTIPATHING GROUPS

Physical interfaces that share the same link–layer broadcast domain must be collected into a single IP Multipathing (IPMP) group using the group subcommand. Each IPMP group has an associated IPMP IP interface, which can either be explicitly created (the preferred method) by using the ipmp subcommand or implicitly created by ifconfig in response to placing an IP interface into a new IPMP group. Implicitly-created IPMP interfaces will be named ipmpN where N is the lowest integer that does not conflict with an existing IP interface name or IPMP group name.

Each IPMP IP interface is created with a matching IPMP group name, though it can be changed using the group subcommand. Each IPMP IP interface hosts a set of highly-available IP addresses. These addresses will remain reachable so long as at least one interface in the group is active, where “active” is defined as having at least one UP address and having INACTIVE, FAILED, and OFFLINE clear. IP addresses hosted on the IPMP IP interface may either be configured statically or configured through DHCP by means of the dhcp subcommand.

Interfaces assigned to the same IPMP group are treated as equivalent and monitored for failure by in.mpathd. Provided that active interfaces in the group remain, IP interface failures (and any subsequent repairs) are handled transparently to sockets-based applications. IPMP is also integrated with the Dynamic Reconfiguration framework (see cfgadm(1M)), which enables network adapters to be replaced in a way that is invisible to sockets-based applications.

The IP module automatically load-spreads all outbound traffic across all active interfaces in an IPMP group. Similarly, all UP addresses hosted on the IPMP IP interface will be distributed across the active interfaces to promote inbound load-spreading. The ipmpstat(1M) utility allows many aspects of the IPMP subsystem to be observed, including the current binding of IP data addresses to IP interfaces.

When an interface is placed into an IPMP group, any UP logical interfaces are “migrated” to the IPMP IP interface for use by the group, unless:

the logical interface is marked NOFAILOVER;
the logical interface hosts an IPv6 link-local address;
the logical interface hosts an IPv4 0.0.0.0 address.

Likewise, once an interface is in a group, if changes are made to a logical interface such that it is UP and not exempted by one of the conditions above, it will also migrate to the associated IPMP IP interface. Logical interfaces never migrate back, even if the physical interface that contributed the address is removed from the group.

Each interface placed into an IPMP group may be optionally configured with a “test” address that in.mpathd will use for probe-based failure detection; see in.mpathd(1M). These addresses must be marked NOFAILOVER (using the -failover subcommand) prior to being marked UP. Test addresses may also be acquired through DHCP by means of the dhcp subcommand.

For more background on IPMP, please see the IPMP–related chapters of the System Administration Guide: Network Interfaces and Network Virtualization.

CONFIGURING IPv6 INTERFACES

When an IPv6 physical interface is plumbed and configured “up” with ifconfig, it is automatically assigned an IPv6 link-local address for which the last 64 bits are calculated from the MAC address of the interface.

example% ifconfig eri0 inet6 plumb up

The following example shows that the link-local address has a prefix of fe80::/10.

example% ifconfig eri0 inet6
ce0: flags=2000841<UP,RUNNING,MULTICAST,IPv6>
           mtu 1500 index 2  
        inet6 fe80::a00:20ff:fe8e:f3ad/10

Link-local addresses are only used for communication on the local subnet and are not visible to other subnets.

If an advertising IPv6 router exists on the link advertising prefixes, then the newly plumbed IPv6 interface will autoconfigure logical interface(s) depending on the prefix advertisements. For example, for the prefix advertisement 2001:0db8:3c4d:0:55::/64, the autoconfigured interface will look like:

eri0:2: flags=2080841<UP,RUNNING,MULTICAST,ADDRCONF,IPv6>
          mtu 1500 index 2
        inet6 2001:0db8:3c4d:55:a00:20ff:fe8e:f3ad/64

Even if there are no prefix advertisements on the link, you can still assign global addresses manually, for example:

example% ifconfig eri0 inet6 addif \
2001:0db8:3c4d:55:a00:20ff:fe8e:f3ad/64 up

To configure boot-time defaults for the interface eri0, place the following entry in the /etc/hostname6.eri0 file:

addif 2001:0db8:3c4d:55:a00:20ff:fe8e:f3ad/64 up

Configuring IP-over-IP Tunnel Interfaces

An IP tunnel is conceptually comprised of two parts: a virtual link between two or more IP nodes, and an IP interface above this link which allows the system to transmit and receive IP packets encapsulated by the underlying link.

The dladm(1M) command is used to configure tunnel links, and ifconfig is used to configure IP interfaces over those tunnel links. An IPv4-over-IPv4 tunnel is created by plumbing an IPv4 interface over an IPv4 tunnel link. An IPv6-over-IPv4 tunnel is created by plumbing an IPv6 interface over an IPv6 tunnel link, and so forth.

When IPv6 interfaces are plumbed over IP tunnel links, their IPv6 addresses are automatically set. For IPv4 and IPv6 tunnels, source and destination link-local addresses of the form fe80::interface-id are configured. For IPv4 tunnels, the interface-id is the IPv4 tunnel source or destination address. For IPv6 tunnels, the interface-id is the last 64 bits of the IPv6 tunnel source or destination address. For example, for an IPv4 tunnel between 10.1.2.3 and 10.4.5.6, the IPv6 link-local source and destination addresses of the IPv6 interface would be fe80::a01:203 and fe80::a04:506. For an IPv6 tunnel between 2000::1234:abcd and 3000::5678:abcd, the IPv6 link-local source and destination addresses of the interface would be fe80::1234:abcd and fe80::5678:abcd. These default link-local addresses can be overridden by specifying the addresses explicitly, as with any other point-to-point interface.

For 6to4 tunnels, a 6to4 global address of the form 2002:tsrc::1/16 is configured. The tsrc portion is the tunnel source IPv4 address. The prefix length of the 6to4 interface is automatically set to 16, as all 6to4 packets (destinations in the 2002::/16 range) are forwarded to the 6to4 tunnel interface. For example, for a 6to4 link with a tunnel source of 75.1.2.3, the IPv6 interface would have an address of 2002:4b01:203::1/16.

Additional IPv6 addresses can be added using the addif option or by plumbing additional logical interfaces.

For backward compatibility, the plumbing of tunnel IP interfaces with special names will implicitly result in the creation of tunnel links without invoking dladm create-iptun. These tunnel names are:

ip.tunN: An IPv4 tunnel
ip6.tunN: An IPv6 tunnel
ip.6to4tunN: A 6to4 tunnel

These tunnels are “implicit tunnels”, denoted with the i flag in dladm show-iptun output. The tunnel links over which these special IP interfaces are plumbed are automatically created, and they are automatically deleted when the last reference is released (that is, when the last IP interface is unplumbed).

The tsrc, tdst, encaplim, and hoplimit options to ifconfig are obsolete and maintained only for backward compatibility. They are equivalent to their dladm(1M) counterparts.

Display of Tunnel Security Settings

The ifconfig output for IP tunnel interfaces indicates whether IPsec policy is configured for the underlying IP tunnel link. For example, a line of the following form will be displayed if IPsec policy is present:

tunnel security settings  -->  use 'ipsecconf -ln -i ip.tun1'

If you do net set security policy, using either ifconfig or ipsecconf(1M), there is no tunnel security setting displayed.

Examples

Example 1 Using the `ifconfig` Command

If your workstation is not attached to an Ethernet, the network interface, for example, eri0, should be marked “down” as follows:

example% ifconfig eri0 down

Example 2 Printing Addressing Information

To print out the addressing information for each interface, use the following command:

example% ifconfig -a

Example 3 Resetting the Broadcast Address

To reset each interface's broadcast address after the netmasks have been correctly set, use the next command:

example% ifconfig -a broadcast +

Example 4 Changing the Ethernet Address

To change the Ethernet address for interface ce0, use the following command:

example% ifconfig ce0 ether aa:1:2:3:4:5

Example 5 Configuring an IP-in-IP Tunnel

To configure an IP-in-IP tunnel, first create an IP tunnel link (tunsrc and tundst are hostnames with corresponding IPv4 entries in /etc/hosts):

example% dladm create-iptun -T ipv4 -s tunsrc -d tundst tun0

Then plumb a point-to-point interface, supplying the source and destination addresses (mysrc and thedst are hostnames with corresponding IPv4 entries in /etc/hosts):

example% ifconfig tun0 plumb mysrc thedst up

Use ipsecconf(1M), as described above, to configure tunnel security properties.

Configuring IPv6 tunnels is done by using a tunnel type of ipv6 with create-iptun. IPv6 interfaces can also be plumbed over either type of tunnel.

Example 6 Configuring 6to4 Tunnels

To configure 6to4 tunnels, first create a 6to4 tunnel link (myv4addr is a hostname with a corresponding IPv4 entry in /etc/hosts):

example% dladm create-iptun -T 6to4 -s myv4addr my6to4tun0

Then an IPv6 interface is plumbed over this link:

example% ifconfig my6to4tun0 inet6 plumb up

The IPv6 address of the interface is automatically set as described above.

Example 7 Configuring IP Forwarding on an Interface

To enable IP forwarding on a single interface, use the following command:

example% ifconfig eri0 router

To disable IP forwarding on a single interface, use the following command:

example% ifconfig eri0 -router

Example 8 Configuring Source Address Selection Using a Virtual Interface

The following command configures source address selection such that every packet that is locally generated with no bound source address and going out on qfe2 prefers a source address hosted on vni0.

example% ifconfig qfe2 usesrc vni0

The ifconfig -a output for the qfe2 and vni0 interfaces displays as follows:

qfe2: flags=1100843<UP,BROADCAST,RUNNING,MULTICAST,ROUTER,IPv4> mtu
  1500 index 4
  usesrc vni0
  inet 1.2.3.4 netmask ffffff00 broadcast 1.2.3.255
  ether 0:3:ba:17:4b:e1
vni0: flags=20011100c1<UP,RUNNING,NOARP,NOXMIT,ROUTER,IPv4,VIRTUAL>
  mtu 0 index 5
  srcof qfe2
  inet 3.4.5.6 netmask ffffffff

Observe, above, the usesrc and srcof keywords in the ifconfig output. These keywords also appear on the logical instances of the physical interface, even though this is a per-physical interface parameter. There is no srcof keyword in ifconfig for configuring interfaces. This information is determined automatically from the set of interfaces that have usesrc set on them.

The following command, using the none keyword, undoes the effect of the preceding ifconfig usesrc command.

example% ifconfig qfe2 usesrc none

Following this command, ifconfig -a output displays as follows:

qfe2: flags=1100843<UP,BROADCAST,RUNNING,MULTICAST,ROUTER,IPv4> mtu
  1500 index 4
  inet 1.2.3.4 netmask ffffff00 broadcast 1.2.3.255
  ether 0:3:ba:17:4b:e1
vni0: flags=20011100c1<UP,RUNNING,NOARP,NOXMIT,ROUTER,IPv4,VIRTUAL>
  mtu 0 index 5
  inet 3.4.5.6 netmask ffffffff

Note the absence of the usesrc and srcof keywords in the output above.

Example 9 Configuring Source Address Selection for an IPv6 Address

The following command configures source address selection for an IPv6 address, selecting a source address hosted on vni0.

example% ifconfig qfe1 inet6 usesrc vni0

Following this command, ifconfig -a output displays as follows:

qfe1: flags=2000841<UP,RUNNING,MULTICAST,IPv6> mtu 1500 index 3
  usesrc vni0
  inet6 fe80::203:baff:fe17:4be0/10
  ether 0:3:ba:17:4b:e0
vni0: flags=2002210041<UP,RUNNING,NOXMIT,NONUD,IPv6,VIRTUAL> mtu 0
  index 5
  srcof qfe1
  inet6 fe80::203:baff:fe17:4444/128
vni0:1: flags=2002210040<RUNNING,NOXMIT,NONUD,IPv6,VIRTUAL> mtu 0
  index 5
  srcof qfe1
  inet6 fec0::203:baff:fe17:4444/128
vni0:2: flags=2002210040<RUNNING,NOXMIT,NONUD,IPv6,VIRTUAL> mtu 0
  index 5
  srcof qfe1
  inet6 2000::203:baff:fe17:4444/128

Depending on the scope of the destination of the packet going out on qfe1, the appropriately scoped source address is selected from vni0 and its aliases.

Example 10 Using Source Address Selection with Shared-IP Zones

The following is an example of how the usesrc feature can be used with the zones(5) facility in Solaris. The following commands are invoked in the global zone:

example% ifconfig hme0 usesrc vni0
example% ifconfig eri0 usesrc vni0
example% ifconfig qfe0 usesrc vni0

Following the preceding commands, the ifconfig -a output for the virtual interfaces would display as:

vni0: flags=20011100c1<UP,RUNNING,NOARP,NOXMIT,ROUTER,IPv4,VIRTUAL>
   mtu 0 index 23
   srcof hme0 eri0 qfe0
   inet 10.0.0.1 netmask ffffffff
vni0:1:
   flags=20011100c1<UP,RUNNING,NOARP,NOXMIT,ROUTER,IPv4,VIRTUAL> mtu 0
   index 23
   zone test1
   srcof hme0 eri0 qfe0
   inet 10.0.0.2 netmask ffffffff
vni0:2:
   flags=20011100c1<UP,RUNNING,NOARP,NOXMIT,ROUTER,IPv4,VIRTUAL> mtu 0
   index 23
   zone test2
   srcof hme0 eri0 qfe0
   inet 10.0.0.3 netmask ffffffff
vni0:3:
   flags=20011100c1<UP,RUNNING,NOARP,NOXMIT,ROUTER,IPv4,VIRTUAL> mtu 0
   index 23
   zone test3
   srcof hme0 eri0 qfe0
   inet 10.0.0.4 netmask ffffffff

There is one virtual interface alias per zone (test1, test2, and test3). A source address from the virtual interface alias in the same zone is selected. The virtual interface aliases were created using zonecfg(1M) as follows:

example% zonecfg -z test1
zonecfg:test1> add net
zonecfg:test1:net> set physical=vni0
zonecfg:test1:net> set address=10.0.0.2

The test2 and test3 zone interfaces and addresses are created in the same way.

Example 11 Turning Off DHCPv6

The following example shows how to disable automatic use of DHCPv6 on all interfaces, and immediately shut down DHCPv6 on the interface named hme0. See in.ndpd(1M) and ndpd.conf(4) for more information on the automatic DHCPv6 configuration mechanism.

example% echo ifdefault StatefulAddrConf false >> /etc/inet/ndpd.conf
example% pkill -HUP -x in.ndpd
example% ifconfig hme0 dhcp release

Files

/etc/netmasks: Netmask data.
/etc/default/inet_type: Default Internet protocol type.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Availability	SUNWcsu
Interface Stability for command-line options	Committed
Interface Stability for command output	Uncommitted

Diagnostics

ifconfig sends messages that indicate if:

the specified interface does not exist
the requested address is unknown
the user is not privileged and tried to alter an interface's configuration

Notes

Do not select the names broadcast, down, private, trailers, up or other possible option names when you choose host names. If you choose any one of these names as host names, it can cause unusual problems that are extremely difficult to diagnose.

SunOS 5.11 Last Revised 11 Nov 2009