ifconfig(1M) System Administration Commands ifconfig(1M)
ifconfig - configure network interface parameters
/sbin/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 authentica-
tion algorithm] [auto-revarp] [ broadcast address] [deprecated | -dep-
recated] [ destination dest_address] [ [failover] | [-failover]] [
group [ [name] | ""] ] [ index {if_index}] [ 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 sub-
net_address] [ tdst tunnel_dest_address] [ token address/pre-
fix_length] [ tsrc tunnel_src_address] [trailers | -trailers] [up]
[down] [xmit | -xmit]
/usr/sbin/ifconfig interface [address_family] [ address [/pre-
fix_length] [dest_address]] [ addif address [/prefix_length]] [
removeif address [/prefix_length]] [arp | -arp] [auth_algs authenti-
cation algorithm] [encr_algs encryption algorithm]
[encr_auth_algs authentication algorithm] [auto-revarp] [ broadcast
address] [deprecated | -deprecated] [ destination dest_address] [
[failover] | [-failover]] [ group [ [name] | ""] ] [ index
{if_index}] [ 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] [xmit | -xmit]
/sbin/ifconfig interface {auto-dhcp | dhcp} [primary] [ wait sec-
onds] drop | extend | inform | ping | release | start | status
/usr/sbin/ifconfig interface {auto-dhcp | dhcp} [primary] [ wait
seconds] drop | extend | inform | ping | release | start | status
The command ifconfig is used to assign an address to a network inter-
face and to configure network interface parameters. The ifconfig com-
mand 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 the superuser
may modify the configuration of a network interface. Options appearing
within braces ({}) indicate that one of the options must be specified.
The two versions of ifconfig, /sbin/ifconfig and /usr/sbin/ifconfig,
behave differently with respect to name services. The order in which
names are looked up by /sbin/ifconfig when the system is booting is
fixed and cannot be changed. In contrast, changing /etc/nsswitch.conf
may affect the behavior of /usr/sbin/ifconfig. The system administrator
may configure the source and lookup order in the tables by means of
the name service switch. See nsswitch.conf(4) for more information.
DHCP Configuration
The third and fourth forms of this command are used to control the
Dynamic Host Configuration Protocol ("DHCP") configuring of the inter-
face. DHCP is only available on interfaces for which the address family
is inet. In this mode, ifconfig is used to control operation of dhcpa-
gent(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, dhcpa-
gent will remove the interface from its control.
The following options are supported:
addif address
Create the next unused logical interface on the specified physi-
cal interface.
arp Enable the use of the Address Resolution Protocol ("ARP") in map-
ping between network level addresses and link level addresses
(default). This is currently implemented for mapping between IPv4
addresses and 10Mb/s Ethernet addresses.
-arp Disable the use of the ARP.
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.
auto-dhcp
Use DHCP to automatically acquire an address for this interface.
This option has a completely equivalent alias called dhcp.
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 pri-
mary at any given time. If another interface is subse-
quently 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 sym-
bolic value forever may be used as well, with obvious mean-
ing.
drop Remove the specified interface from DHCP control. Addition-
ally, set the IP address to zero and mark the interface as
"down".
extend
Attempt to extend the lease on the interface's IPv4
address. This is not required, as the agent will automati-
cally extend the lease well before it expires.
inform
Obtain network configuration parameters from DHCP without
obtaining a lease on an IP address. This is useful in situ-
ations 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.
This subcommand has no meaning when the named interface
represents more than one interface.
release
Relinquish the IPv4 address on the interface, and mark the
interface as "down."
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 automati-
cally acquire an address for this interface.
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 argu-
ments 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 address as a deprecated address. Addresses marked as
deprecated will not be used as source address for outbound pack-
ets unless either there are no other addresses available on this
interface or the application has bound to this address explic-
itly. The status display shows DEPRECATED as part of flags.
-deprecated
Marks the address as not deprecated.
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 an interface "down". When an interface is marked "down", the
system does not attempt to transmit messages through that inter-
face. If possible, the interface is reset to disable reception as
well. This action does not automatically disable routes using the
interface.
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 speci-
fied, but the encryption algorithm is not, the default value for
the ESP encryption will be null.
-failover
Mark the address as a non-failover address.Addresses marked this
way will not failover when the interface fails. Status display
shows "NOFAILOVER" as part of flags.
failover
Mark the address as a failover address. This address will
failover when the interface fails. Status display does not show
"NOFAILOVER" as part of flags.
group [ name |""]
Insert the interface in the multipathing group specified by name.
To delete an interface from a group, use a null string "".
When invoked on the logical interface with id zero, the status
display shows the 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.
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 hme0 modinsert ipqos@2
A subsequent listing of all the modules in the stream of the
device follows:
example% ifconfig hme0 modlist
0 arp
1 ip
2 ipqos
3 firewall
4 hme
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 hme0 modlist
0 arp
1 ip
2 firewall
4 hme
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 hme0 modremove firewall@3
A subsequent listing of all the modules in the stream of the
device follows:
example% ifconfig hme0 modlist
0 arp
1 ip
2 ipqos
3 hme
Note that the core IP stack modules, for example, ip and tun mod-
ules, 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.
netmask mask
For IPv4 only. Specify how much of the address to reserve for
subdividing networks into subnetworks. The mask includes the net-
work 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:
1. with a single hexadecimal number with a leading 0x,
2. with a dot-notation address,
3. with a "+" (plus sign) address, or
4. with a pseudo host name/pseudo network name found in the net-
work 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 sub-
netmasks 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 inter-
faces 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-go interface.
-nud Disables the neighbor unreachability detection mechanism on a
point-to-go interface.
plumb Open the device associated with the physical interface name and
set up the streams needed for IP to use the device. When used
with a logical interface name, this command is used to create a
specific named logical interface. An interface must be separately
plumbed for use by IPv4 and IPv6. The address_family parameter
controls whether the ifconfig command applies to IPv4 or IPv6.
Before an interface has been plumbed, , the interface will not
show up in the output of the ifconfig -a command.
private
Tells the in.routed routing daemon that the 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.
set Set the address, prefix_length or both, for an interface.
standby
Marks the physical interface as a standby interface. If the
interface is marked STANDBY and is part of the multipathing
group, the interface will not be selected to send out packets
unless some other interface in the group has failed and the net-
work access has been failed over to this standby interface.
The status display shows "STANDBY, INACTIVE" indicating that
that the interface is a standby and is also inactive. IFF_INAC-
TIVE will be cleared when some other interface belonging to the
same multipathing group fails over to this interface. Once a
failback happens, the status display will return to INACTIVE.
-standby
Turns off standby on this interface.
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.
token address/prefix_length
Set the IPv6 token of an interface to be used for address auto-
configuration.
example% ifconfig hme0 inet6 token ::1/64
trailers
This flag previously caused a nonstandard encapsulation of inet
packets on certain link levels. Drivers supplied with this
release no longer use this flag. It is provided for compatibil-
ity, 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.
unplumb
Close the device associated with this physical interface name and
any streams that ifconfig set up for IP to use the device. When
used with a logical interface name, the logical interface is
removed from the system. After this command is executed, the
device name will no longer appear in the output of ifconfig -a.
up Mark an interface "up". This happens automatically when setting
the first address on an interface. The up option enables an
interface after an ifconfig down, which reinitializes the hard-
ware.
xmit Enable an interface to transmit packets. This is the default
behavior when the interface is up.
-xmit Disable transmission of packets on an interface. The interface
will continue to receive packets.
The interface operand, as well as address parameters that affect it,
are described below.
interface
A string of the form, name physical-unit, for example, le0
or ie1; or of the form name physical-unit:logical-unit,
for example, le0:1; or of the form ip.tunN, for tunnels.
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 commands to all interfaces in the system.
-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.
-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: ether, inet, and inet6. If no address
family is specified, the default is inet.
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 nota-
tion".
For the IPv6 family (inet6), the address is either a host
name present in the host name data base (see ipnodes(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.
For the ether address family, the address is an Ethernet
address represented as x:x:x: x:x:x where x is a hexadeci-
mal number between 0 and FF.
Some, though not all, of the 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. The use of interface groups should be
restricted to those cards with their own addresses (see
INTERFACE GROUPS).
prefix_length
For the IPv4 and IPv6 families (inet and inet6), the pre-
fix_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 inter-
face 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 tunnel_dest_address
being configured.
tunnel_src_address
As address that is attached to an already configured
interface that has been configured "up" with ifconfig.
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 net-
work 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 com-
mand. For example:
example% ifconfig le0 plumb
Once a physical interface has been "plumbed", logical interfaces asso-
ciated with the physical interface can be configured by separate plumb
or addif options to the ifconfig command.
example% ifconfig le0:1 plumb
allocates a specific logical interface associated with the physical
interface le0. The command
example% ifconfig le0 addif 192.9.200.1/24 up
allocates the next available logical unit number on the le0 physical
interface and assigns an address and prefix_length.
A logical interface can be configured with parameters ( address,pre-
fix_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 log-
ical interface must be associated with an existing and "up" physical
interface. So, for example, the logical interface le0:1 can only be
configured after the physical interface le0 has been plumbed.
To delete a logical interface, use the unplumb or removeif options. For
example,
example% ifconfig le0:1 down unplumb
will delete the logical interface le0:1.
If a physical interface shares an IP prefix with another interface,
these interfaces are collected into an interface group. IP uses an
interface group to rotate source address selection when the source
address is unspecified, and in the case of multiple physical interfaces
in the same group, to scatter traffic across different IP addresses on
a per-IP-destination basis. See netstat(1M) for per-IP-destination
information.
This feature may be enabled by using ndd(1M).
One can also use the group keyword to form a multipathing group. When
multipathing groups are used, the functionality of the interface group
is subsumed into the functionality of the multipathing group. A multi-
pathing group provides failure detection and repair detection for the
interfaces in the group. See in.mpathd(1M) and System Administration
Guide, Volume 3.
The interface groups formed using ndd(1M) will be made obsolete in the
future. Accordingly, it is advisable to use form multipathing groups
using the group keyword.
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.
ifconfig le0 inet6 plumb up
The following example shows that the link-local address has a prefix of
fe80::/10.
example% ifconfig le0 inet6
le0: flags=2000841<UP,RUNNING,MULTICAST,IPv6>
mtu 1500 index 2
inet6 fe80::a00:20ff:fe8e:f3ad/10
If an advertising IPv6 router exists on the link advertising prefixes,
then the newly plumbed IPv6 interface will autoconfigure logical inter-
face(s) depending on the prefix advertisements. For example, for prefix
advertisements fec0:0:0:55::/64 and 3ff0:0:0:55::/64, the autoconfig-
ured interfaces will look like:
le0:1: flags=2080841<UP,RUNNING,MULTICAST,ADDRCONF,IPv6>
mtu 1500 index 2
inet6 fec0::55:a00:20ff:fe8e:f3ad/64
le0:2: flags=2080841<UP,RUNNING,MULTICAST,ADDRCONF,IPv6>
mtu 1500 index 2
inet6 3ff0::55:a00:20ff:fe8e:f3ad/64
Even if there are no prefix advertisements on the link, you can still
assign site-local and global addresses manually, for example:
example% ifconfig le0 inet6 addif fec0::55:a00:20ff:fe8e:f3ad/64 up
example% ifconfig le0 inet6 addif 3ff0::55:a00:20ff:fe8e:f3ad/64 up
To configure boot-time defaults for the interface le0, place the fol-
lowing entries in the /etc/hostname6.le0 file:
addif fec0::55:a00:20ff:fe8e:f3ad/64 up
addif 3ff0::55:a00:20ff:fe8e:f3ad/64 up
Link-local addresses are only used for on-link communication and are
not visible to other subnets.
Configuring IPv6/IPv4 tunnels
An IPv6 over IPv4 tunnel interface can send and receive IPv6 packets
encapsulated in an IPv4 packet. Create tunnels at both ends pointing
to each other. IPv6 over IPv4 tunnels require the tunnel source and
tunnel destination IPv4 and IPv6 addresses. Solaris 8 supports both
automatic and configured tunnels. For automatic tunnels, an IPv4-com-
patible IPv6 address is used. The following demonstrates auto-tunnel
configuration:
example% ifconfig ip.atun0 inet6 plumb
example% ifconfig ip.atun0 inet6 tsrc <IPv4-address> \
::<IPv4 address>/96 up
where IPv4-address is the IPv4 address of the interface through which
the tunnel traffic will flow, and IPv4-address, ::<IPv4-address>, is
the corresponding IPv4-compatible IPv6 address.
The following is an example of a configured tunnel:
example% ifconfig ip.tun0 inet6 plumb tsrc <my-ipv4-address> \
tdst <peer-ipv4-address> up
This creates a configured tunnel between my-ipv4-address and peer-
ipv4-address with corresponding link-local addresses. For tunnels with
global or site-local addresses, the logical tunnel interfaces need to
be configured in the following form:
ifconfig ip.tun0 inet6 addif <my-v6-address> <peer-v6-address> up
For example,
example% ifconfig ip.tun0 inet6 plumb tsrc 109.146.85.57 \
tdst 109.146.85.212 up
example% ifconfig ip.tun0 inet6 addif 2::45 2::46 up
To show all IPv6 interfaces that are up and configured:
example% ifconfig -au6
ip.tun0: flags=2200851<UP,POINTOPOINT,RUNNING,MULTICAST,NONUD,IPv6>
mtu 1480 index 3
inet tunnel src 109.146.85.57 tunnel dst 109.146.85.212
inet6 fe80::6d92:5539/10 --> fe80::6d92:55d4
ip.tun0:1: flags=2200851<UP,POINTOPOINT,RUNNING,MULTICAST,NONUD,IPv6>
mtu 1480 index 3
inet6 2::45/128 --> 2::46
Example 1: Using the ifconfig Command
If your workstation is not attached to an Ethernet, the le0 interface
should be marked "down" as follows:
example% ifconfig le0 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 le0, use the following
command:
example% ifconfig le0 ether aa:1:2:3:4:5
Example 5: Configuring an IP-in-IP Tunnel
To configure an IP-in-IP tunnel, first plumb it with the following com-
mand:
example% ifconfig ip.tun0 plumb
Then configure it as a point-to-point interface, supplying the tunnel
source and the tunnel destination:
example% ifconfig ip.tun0 myaddr mydestaddr tsrc another_myaddr \
tdst a_dest_addr up
Tunnel security properties must be configured on one invocation of
ifconfig:
example% ifconfig ip.tun0 encr_auth_algs md5 encr_algs 3des
Example 6: Requesting a Service Without Algorithm Preference
To request a service without any algorithm preferences, specify any:
example% ifconfig ip.tun0 encr_auth_algs any encr_algs any
Example 7: Disabling All Security
To disable all security, specify any security service with none as the
algorithm value:
example% ifconfig ip.tun0 auth_algs none
or
example% ifconfig ip.tun0 encr_algs none
/etc/netmasks
netmask data
See attributes(5) for descriptions of the following attributes:
/usr/sbin
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|Interface Stability for |Evolving |
|options modlist, modinsert, | |
|and modremove | |
+-----------------------------+-----------------------------+
/sbin
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsr |
+-----------------------------+-----------------------------+
|Interface Stability for |Evolving |
|options modlist, modinsert, | |
|and modremove | |
+-----------------------------+-----------------------------+
dhcpinfo(1), dhcpagent(1M), in.mpathd(1M), in.routed(1M), ndd(1M), net-
stat(1M), ethers(3SOCKET), gethostbyname(3NSL), getnetbyname(3SOCKET),
hosts(4), netmasks(4), networks(4), nsswitch.conf(4), attributes(5),
arp(7P),ipsecah(7P),ipsecesp(7P),tun(7M)
System Administration Guide, Volume 3
ifconfig sends messages that indicate if:
+o the specified interface does not exist
+o the requested address is unknown
+o the user is not privileged and tried to alter an interface's con-
figuration
It is recommended that the names broadcast, down, private, trailers,
up, and the other possible option names not be selected when choosing
host names. Choosing any one of these names as host names will cause
bizarre problems that can be extremely difficult to diagnose.
SunOS 5.9 19 Dec 2001 ifconfig(1M)