ifconfig —
configure network interface parameters
ifconfig |
[-AaC] [interface]
[address_family] [address
[dest_address]]
[parameters] |
The ifconfig utility is used to assign an
address to a network interface and/or configure network interface
parameters. Generally speaking,
hostname.if(5) files are used at
boot-time to define the network address of each interface present on a
machine; ifconfig is used at a later time to
redefine an interface's address or other operating parameters.
ifconfig displays the current
configuration for a network interface when no optional parameters are
supplied. If a protocol family is specified,
ifconfig will report only the details specific to
that protocol family. If no parameters are provided, a summary of all
interfaces is provided.
Only the superuser may modify the configuration of a network
interface.
The following options are available:
-A- Causes full interface alias information for each interface to be
displayed.
-a- Causes
ifconfig to print information on all
interfaces. The protocol family may be specified as well. This is the
default, if no parameters are given to
ifconfig.
-C- Print the names of all network pseudo-devices that can be created
dynamically at runtime using
ifconfig
create.
- interface
- The interface parameter is a string of the form
“name unit”, for example, “en0”. If no
optional parameters are supplied, this string can instead be just
“name”. If an interface group of that name exists, all
interfaces in the group will be shown. Otherwise all interfaces of the
same type will be displayed (for example, “fxp” will display
all fxp(4) interfaces).
- address_family
- Specifies the address family which affects interpretation of the remaining
parameters. Since an interface can receive transmissions in differing
protocols with different naming schemes, specifying the address family is
recommended. The address or protocol families currently supported are
“inet” and “inet6”.
- address
- An Internet version 4 or 6 address. Valid formats are dot notation (IPv4),
colon-separated (IPv6), CIDR notation, or a host name present in the host
name database, hosts(5).
- dest_address
- Specify the address of the correspondent on the other end of a
point-to-point link.
The following parameters may be set with
ifconfig:
alias- Establish an additional network address for this interface. This is
sometimes useful when changing network numbers, and one wishes to accept
packets addressed to the old interface.
-alias- A synonym for
delete. Use of this option is
discouraged in favour of delete.
arp- Enable the use of the Address Resolution Protocol (ARP) in mapping between
network level addresses and link level addresses (default).
-arp- Disable the use of ARP.
autoconf- Set the AUTOCONF4 or AUTOCONF6 flag on
the interface, depending on address_family.
slaacd(8) automatically configures IPv6
addresses for interfaces with AUTOCONF6 set.
dhcpleased(8) automatically
configures IPv4 addresses (using DHCP protocol) for interfaces with
AUTOCONF4 set.
-autoconf- Unset the AUTOCONF4 or AUTOCONF6 flag
on the interface, depending on address_family.
broadcast
addr- (inet 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.
create- Create the specified network pseudo-device. At least the following devices
can be created on demand:
aggr(4),
bpe(4),
bridge(4),
carp(4),
egre(4),
enc(4),
eoip(4),
etherip(4),
gif(4),
gre(4),
lo(4),
mgre(4),
mpe(4),
mpw(4),
nvgre(4),
pair(4),
pflog(4),
pflow(4),
pfsync(4),
ppp(4),
pppoe(4),
svlan(4),
switch(4),
tap(4),
tpmr(4),
trunk(4),
tun(4),
vether(4),
vlan(4),
vxlan(4),
wg(4)
debug- Enable driver-dependent debugging code; usually, this turns on extra
console error logging.
-debug- Disable driver-dependent debugging code.
delete- Remove the default inet address associated with the interface, including
any netmask or destination address configured with it. An address and
address family can be given to make the deletion more specific.
description
value- Specify a description of the interface. This can be used to label
interfaces in situations where they may otherwise be difficult to
distinguish.
-description- Clear the interface description.
destroy- Destroy the specified network pseudo-device.
down- Mark an interface “down”. When an interface is marked
“down”, the system will not attempt to transmit messages
through that interface. If possible, the interface will be reset to
disable reception as well. This action automatically disables routes using
the interface.
group
group-name- Assign the interface to a group. The group-name may
not be longer than 15 characters and must not end with a digit. Any
interface can be in multiple groups.
For instance, a group could be used to create a hardware
independent pf(4) ruleset (i.e. not one
based on the names of NICs) using existing (egress, carp, etc.) or
user-defined groups.
Some interfaces belong to specific groups by default:
- All interfaces are members of the “all” interface
group.
- Cloned interfaces are members of their interface family group. For
example, a PPP interface such as “ppp0” is a member of
the “ppp” interface family group.
- pppx(4) interfaces are members of the
“pppx” interface group.
- The interfaces the default routes point to are members of the
“egress” interface group.
- IEEE 802.11 wireless interfaces are members of the
“wlan” interface group.
- Any interfaces used for network booting are members of the
“netboot” interface group.
-group
group-name- Remove the interface from the given group.
hwfeatures- Display the interface hardware features:
-inet- Remove all configured inet(4) addresses
on the given interface.
-inet6- Disable inet6(4) on the given interface
and remove all configured inet6(4)
addresses, including the link-local ones. This is the default. To turn
inet6 on, use
eui64 or
autoconf, or assign any inet6 address.
instance
minst- Set the media instance to minst. This is useful for
devices which have multiple physical layer interfaces (PHYs). Setting the
instance on such devices may not be strictly required by the network
interface driver as the driver may take care of this automatically; see
the driver's manual page for more information.
link[0-2]- Enable special processing of the link level of the interface. These three
options are interface specific in actual effect; however, they are in
general used to select special modes of operation. An example of this is
to select the connector type for some Ethernet cards. Refer to the man
page for the specific driver for more information.
-link[0-2]- Disable special processing at the link level with the specified
interface.
lladdr
etheraddr|random- Change the link layer address (MAC address) of the interface. This should
be specified as six colon-separated hex values, or can be chosen
randomly.
llprio
prio- Set the priority for link layer communications
(arp(4),
bpf(4),
pppoe(4)).
media
[type]- Set the media type of the interface to type. If no
argument is given, display a list of all available media.
Some interfaces support the mutually exclusive use of one of
several different physical media connectors. For example, a 10Mb/s
Ethernet interface might support the use of either AUI or twisted pair
connectors. Setting the media type to “10base5” or
“AUI” would change the currently active connector to the
AUI port. Setting it to “10baseT” or “UTP”
would activate twisted pair. Refer to the interface's driver-specific
man page for a complete list of the available types, or use the
following command for a listing of choices:
$ ifconfig interface
media
mediaopt
opts- Set the specified media options on the interface.
opts is a comma delimited list of options to apply
to the interface. Refer to the interface's driver-specific man page for a
complete list of available options, or use the following command for a
listing of choices:
$ ifconfig interface
media
-mediaopt
opts- Disable the specified media options on the interface.
metric
nhops- Set the routing metric of the interface to nhops,
default 0. The routing metric can be used by routing protocols. Higher
metrics have the effect of making a route less favorable.
mode
mode- If the driver for the interface supports the media selection system, force
the mode of the interface to the given mode. For
IEEE 802.11 wireless interfaces that support multiple modes, this
directive is used to select between 802.11a (“11a”), 802.11b
(“11b”), 802.11g (“11g”), and 802.11n
(“11n”) modes.
-mode- Select the mode automatically. This is the default for IEEE 802.11
wireless interfaces.
monitor- Enable monitor mode on the interface, preventing the processing of
incoming packets by the network stack.
-monitor- Disable monitor mode on the interface, allowing the processing of incoming
packets by the network stack.
mpls- Enable Multiprotocol Label Switching (MPLS) on the interface, allowing it
to send and receive MPLS traffic.
-mpls- Disable MPLS on the interface.
mtu
value- Set the MTU for this device to the given value.
Cloned routes inherit this value as a default. For Ethernet devices which
support setting the MTU, a value greater than 1500 enables jumbo frames.
The hardmtu output from
hwfeatures shows the maximum supported MTU.
netmask
mask- (inet and inet6 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 can be specified as a single hexadecimal
number with a leading 0x, or with a dot-notation Internet 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.
prefixlen
n- (inet and inet6 only) Effect is similar to
netmask, but you can specify prefix length by
digits.
priority
n- Set the interface routing priority to n.
n is in the range of 0 to 15 with smaller numbers
being better. The default priority of an interface is 0, except for IEEE
802.11 wireless interfaces (priority 4),
umb(4) interfaces (priority 6), and
carp(4) interfaces (priority 15). The
default priority of newly connected routes (routes created by configuring
an IP address on an interface) is calculated by adding 4 (RTP_CONNECTED)
to the interface priority. The default priority of new static routes added
to the kernel is calculated by adding 8 (RTP_STATIC) to the interface
priority.
rdomain
rdomainid- Attach the interface to the routing domain with the specified
rdomainid. Interfaces in different routing domains
are separated and cannot directly pass traffic between each other. It is
therefore possible to reuse the same addresses in different routing
domains. If the specified rdomain does not yet exist it will be created,
including a routing table with the same id. By default all interfaces
belong to routing domain 0.
-rdomain- Remove the interface from the routing domain and return it to routing
domain 0. Any inet and inet6 addresses on the interface will also be
removed.
rtlabel
route-label- (inet) Attach route-label to new network routes of
the specified interface. Route labels can be used to implement policy
routing; see route(4),
route(8), and
pf.conf(5).
-rtlabel- Clear the route label.
staticarp- If ARP is enabled, the host will only reply to requests for its addresses,
and will never send any requests.
-staticarp- If ARP is enabled, the host will perform normally, sending out requests
and listening for replies.
transceiver- Query and display information and diagnostics from GBIC and SFP modules
installed in an interface. It is only supported by drivers implementing
the necessary functionality on hardware which supports it.
up- Mark an interface “up”. This may be used to enable an
interface after an
ifconfig down. It happens
automatically when setting the first address on an interface. If the
interface was reset when previously marked down, the hardware will be
re-initialized.
wol- Enable Wake on LAN (WoL). When enabled, reception of a WoL frame will
cause the network card to power up the system from standby or suspend
mode. WoL frames are sent using
arp(8).
-wol- Disable WoL. WoL is disabled at boot by the driver, if possible.
ifconfig |
bpe-interface
[[-]parent parent-interface]
[vnetid vnetid-tag] |
The following options are available for
bpe(4) interfaces:
parent
parent-interface- Associate the BPE interface with the interface
parent-interface.
-parent- Disassociate from the parent interface. This breaks the link between the
BPE interface and its parent.
vnetid
vnetid-tag- Set the virtual network identifier tag value to
vnetid-tag. This is a 24-bit value in the range 0 to
16777215.
The following options are available for a
bridge(4) interface:
add
interface- Add interface as a member of the bridge. The
interface is put into promiscuous mode so that it can receive every packet
sent on the network. An interface can be a member of at most one
bridge.
addr- Display the addresses that have been learned by the bridge.
addspan
interface- Add interface as a span port on the bridge.
autoedge
interface- Automatically detect the spanning tree edge port status on
interface. This is the default for interfaces added
to the bridge.
-autoedge
interface- Disable automatic spanning tree edge port detection on
interface.
autoptp
interface- Automatically detect the point-to-point status on
interface by checking the full duplex link status.
This is the default for interfaces added to the bridge.
-autoptp
interface- Disable automatic point-to-point link detection on
interface.
blocknonip
interface- Mark interface so that only IPv4, IPv6, ARP, and
Reverse ARP packets are accepted from it or forwarded to it from other
bridge member interfaces.
-blocknonip
interface- Allow non-IPv4, IPv6, ARP, or Reverse ARP packets through
interface.
del
interface- Remove interface from the bridge. Promiscuous mode
is turned off for the interface when it is removed from the bridge.
deladdr
address- Delete address from the cache.
delspan
interface- Delete interface from the list of span ports of the
bridge.
discover
interface- Mark interface so that packets are sent out of the
interface if the destination port of the packet is unknown. If the bridge
has no address cache entry for the destination of a packet, meaning that
there is no static entry and no dynamically learned entry for the
destination, the bridge will forward the packet to all member interfaces
that have this flag set. This is the default for interfaces added to the
bridge.
-discover
interface- Mark interface so that packets are not sent out of
the interface if the destination port of the packet is unknown. Turning
this flag off means that the bridge will not send packets out of this
interface unless the packet is a broadcast packet, multicast packet, or a
packet with a destination address found on the interface's segment. This,
in combination with static address cache entries, prevents potentially
sensitive packets from being sent on segments that have no need to see the
packet.
down- Stop the bridge from forwarding packets.
edge
interface- Set interface as a spanning tree edge port. An edge
port is a single connection to the network and cannot create bridge loops.
This allows a straight transition to forwarding.
-edge
interface- Disable edge port status on interface.
flush- Remove all dynamically learned addresses from the cache.
flushall- Remove all addresses from the cache including static addresses.
flushrule
interface- Remove all Ethernet MAC filtering rules from
interface.
fwddelay
time- Set the time (in seconds) before an interface begins forwarding packets.
Defaults to 15 seconds, minimum of 4, maximum of 30.
hellotime
time- Set the time (in seconds) between broadcasting spanning tree protocol
configuration packets. Defaults to 2 seconds, minimum of 1, maximum of 2.
This option is only supported in STP mode with rapid transitions disabled;
see the
proto command for setting the protocol
version.
holdcnt
time- Set the transmit hold count, which is the number of spanning tree protocol
packets transmitted before being rate limited. Defaults to 6, minimum of
1, maximum of 10.
ifcost
interface num- Set the spanning tree path cost of interface to
num. Defaults to 55, minimum of 1, maximum of
200000000 in RSTP mode, and maximum of 65535 in STP mode.
-ifcost
interface- Automatically calculate the spanning tree priority of
interface based on the current link speed, interface
status, and spanning tree mode. This is the default for interfaces added
to the bridge.
ifpriority
interface num- Set the spanning tree priority of interface to
num. Defaults to 128, minimum of 0, maximum of
240.
learn
interface- Mark interface so that the source address of packets
received from the interface are entered into the address cache. This is
the default for interfaces added to the bridge.
-learn
interface- Mark interface so that the source address of packets
received from interface are not entered into the address cache.
link0- Setting this flag stops all IP multicast packets from being forwarded by
the bridge.
-link0- Clear the
link0 flag on the bridge interface.
link1- Setting this flag stops all non-IP multicast packets from being forwarded
by the bridge.
-link1- Clear the
link1 flag on the bridge interface.
link2- Setting this flag causes all packets to be passed on to
ipsec(4) for processing, based on the
policies established by the administrator using the
ipsecctl(8) command and
ipsec.conf(5). If appropriate
security associations (SAs) exist, they will be used to encrypt or decrypt
the packets. Otherwise, any key management daemons such as
isakmpd(8) that are running on the
bridge will be invoked to establish the necessary SAs. These daemons have
to be configured as if they were running on the host whose traffic they
are protecting (i.e. they need to have the appropriate authentication and
authorization material, such as keys and certificates, to impersonate the
protected host(s)).
-link2- Clear the
link2 flag on the bridge interface.
maxaddr
size- Set the address cache size to size. The default is
100 entries.
maxage
time- Set the time (in seconds) that a spanning tree protocol configuration is
valid. Defaults to 20 seconds, minimum of 6, maximum of 40.
protected
interface ids- Put interface in protected domains.
ids is a comma delimited list of domain IDs, between
1 and 31, to put the interface in. Interfaces that are part of a protected
domain cannot forward traffic to any other interface in that domain.
Interfaces do not belong to any protected domain by default.
-protected
interface- Remove interface from all protected domains.
proto
value- Force the spanning tree protocol version. The available values are
rstp to operate in the default Rapid Spanning Tree
(RSTP) mode or stp to force operation in Spanning
Tree (STP) mode with rapid transitions disabled.
ptp
interface- Set interface as a point-to-point link. This is
required for straight transitions to forwarding and should be enabled for
a full duplex link or a trunk(4) with at
least two physical links to the same network segment.
-ptp
interface- Disable point-to-point link status on interface.
This should be disabled for a half duplex link and for an interface
connected to a shared network segment, like a hub or a wireless
network.
rule
block|pass
[in | out]
on interface
[src lladdr]
[dst lladdr]
[tag tagname]
[arp|rarp
[request | reply]
[sha lladdr]
[spa ipaddr]
[tha lladdr]
[tpa ipaddr]]- Add a filtering rule to an interface. Rules have a similar syntax to those
in pf.conf(5). Rules can be used to
selectively
block or pass
frames based on Ethernet MAC addresses or to tag
packets for pf(4) to filter on.
arp(4) packets can be matched
with the arp keyword for regular packets and
rarp for reverse arp.
request and reply limit
matches to requests or replies. The source and target host addresses can
be matched with the sha and
tha keywords, and the protocol addresses with
spa and tpa.
Rules are processed in the order in which they were added to
the interface. The first rule matched takes the action (block or pass)
and, if given, the tag of the rule. If no source or destination address
is specified, the rule will match all frames (good for creating a
catchall policy).
rulefile
filename- Load a set of rules from the file filename.
rules
interface- Display the active filtering rules in use on
interface.
spanpriority
num- Set the spanning priority of this bridge to num.
Defaults to 32768, minimum of 0, maximum of 61440.
static
interface address- Add a static entry into the address cache pointing to
interface. Static entries are never aged out of the
cache or replaced, even if the address is seen on a different
interface.
stp
interface- Enable spanning tree protocol on interface.
-stp
interface- Disable spanning tree protocol on interface. This is
the default for interfaces added to the bridge.
timeout
time- Set the timeout, in seconds, for addresses in the cache to
time. The default is 240 seconds. If
time is set to zero, then entries will not be
expired.
up- Start the bridge forwarding packets.
ifconfig |
carp-interface
[advbase n]
[advskew n]
[balancing mode]
[carpnodes vhid:advskew,vhid:advskew,...]
[carpdev iface]
[[-]carppeer peer_address]
[pass passphrase]
[state state]
[vhid host-id] |
The following options are available for a
carp(4) interface:
advbase
n- Set the base advertisement interval to n seconds.
Acceptable values are 0 to 254; the default value is 1 second.
advskew
n- Skew the advertisement interval by n. Acceptable
values are 0 to 254; the default value is 0.
balancing
mode- Set the load balancing mode to mode. Valid modes are
ip, ip-stealth, and
ip-unicast.
carpnodes
vhid:advskew,vhid:advskew,...- Create a load balancing group consisting of up to 32 nodes. Each node is
specified as a vhid:advskew tuple in a
comma-separated list.
carpdev
iface- Attach to parent interface iface.
carppeer
peer_address- Send the carp advertisements to a specified point-to-point peer or
multicast group instead of sending the messages to the default carp
multicast group. The peer_address is the IP address
of the other host taking part in the carp cluster. With this option,
carp(4) traffic can be protected using
ipsec(4) and it may be desired in
networks that do not allow or have problems with IPv4 multicast
traffic.
-carppeer- Send the advertisements to the default carp multicast group.
pass
passphrase- Set the authentication key to passphrase. There is
no passphrase by default.
state
state- Explicitly force the interface to enter this state. Valid states are
init, backup, and
master.
vhid
n- Set the virtual host ID to n. Acceptable values are
1 to 255.
Taken together, the advbase and
advskew indicate how frequently, in seconds, the
host will advertise the fact that it considers itself master of the virtual
host. The formula is advbase +
(advskew / 256). If the master does not advertise
within three times this interval, this host will begin advertising as
master.
ifconfig |
wireless-interface
[[-]bssid bssid]
[[-]chan [n]]
[[-]join id]
[[-]joinlist]
[[-]nwflag flag]
[[-]nwid id]
[[-]nwkey key]
[[-]powersave [duration]]
[scan]
[[-]wpa]
[wpaakms akm,akm,...]
[wpaciphers cipher,cipher,...]
[wpagroupcipher cipher]
[[-]wpakey passphrase | hexkey]
[wpaprotos proto,proto,...] |
The following options are available for a wireless interface:
bssid
bssid- Set the desired BSSID.
-bssid- Unset the desired BSSID. The interface will automatically select a BSSID
in this mode, which is the default.
chan
[n]- Set the channel (radio frequency) to n.
With no channel specified, show the list of channels supported
by the device.
-chan- Unset the desired channel. It doesn't affect the channel to be created for
IBSS or Host AP mode.
join
id- Add the network with ESSID id to the
join list. The interface will automatically
attempt to connect to networks on this list if they are found during a
scan.
The id can either be a printable ASCII
string up to 32 characters in length, or a series of hexadecimal digits
up to 64 digits preceded by “0x”. If
id is the empty string ("") and none of
the networks on the join list are found during a
scan, the interface will automatically connect to any available
networks, provided they do not require WEP or WPA authentication.
Apart from the id, the
join list will record
wpakey, wpaprotos, or
nwkey parameters for the network, provided they
are passed in the same invocation of ifconfig.
Because multiple access points may exist in a given network, the
mode (11a/11b/11g/11n),
chan, and bssid
parameters cannot be stored with join. However,
they may be used separately to force the selection of a particular
access point when the automatic access point selection turns out to be
suboptimal.
join and nwid
cannot be used together in the same invocation of
ifconfig.
-join
id- Remove the network with ESSID id from the
join list and disconnect the interface from the
access point if it is currently connected to this network. The interface
will keep scanning for access points as long as it remains marked as
“up”. A new connection will be established either if a
network on the join list is found during the scan
or if a network ID is configured with nwid.
joinlist- Show the list of networks stored on the
join
list.
-joinlist- Remove all networks from the
join list.
nwflag
flag- Set specified flag. The flag name can be:
- hidenwid
- The ‘
hidenwid’ flag will hide
the network ID (ESSID) in beacon frames when operating in Host AP
mode. It will also prevent responses to probe requests with an
unspecified network ID.
- nobridge
- The ‘
nobridge’ flag will disable
the direct bridging of frames between associated nodes when operating
in Host AP mode. Setting this flag will block and filter direct
inter-station communications.
- nomimo
- The ‘
nomimo’ flag will disable
MIMO reception and transmission even if the driver and wireless
network device support MIMO. This flag can be used to work around
packet loss in 11n mode if the wireless network device has unused
antenna connectors.
- stayauth
- The ‘
stayauth’ flag will cause
the interface to ignore deauth frames. This flag should only be used
on wifi networks which are being attacked with spoofed deauth frames.
It breaks interoperability with spectrum management solutions and
access points that perform band-steering of clients.
Note that the ‘hidenwid’
and ‘nobridge’ options do not
provide any security. The hidden network ID will be sent in clear text
by associating stations and can be easily discovered with tools like
tcpdump(8) and
hostapd(8).
-nwflag
flag- Remove specified flag.
nwid
id- Connect to the network with NWID/ESSID id. The
id can either be a printable ASCII string up to 32
characters in length, or a series of hexadecimal digits up to 64 digits
preceded by “0x”.
Unlike join, the
nwid option only allows one network to be
configured at a time. The nwid option may not be
used together with join in the same invocation
of ifconfig but may be used to momentarily
override the automatic selection of networks stored in the
join list.
-nwid- Clear the network ID configured with
nwid and
disconnect the interface from the access point if it is currently
connected to this network. The interface will keep scanning for access
points as long as it remains marked as “up”. A new
connection will be established either if a network on the
join list is found during the scan or if a network
ID is configured with nwid.
nwkey
key- Enable WEP encryption using the specified key. The
key can either be a string, a series of hexadecimal
digits (preceded by ‘0x’), or a set of keys of the form
“n:k1,k2,k3,k4” where ‘n’ specifies which of
the keys will be used for transmitted packets, and the four keys,
“k1” through “k4”, are configured as WEP keys.
If a set of keys is specified, a comma (‘,’) within the key
must be escaped with a backslash. Note that if multiple keys are used,
their order must be the same within the network.
The length of each key must be either 40 bits for 64-bit
encryption (5-character ASCII string or 10 hexadecimal digits) or 104
bits for 128-bit encryption (13-character ASCII string or 26 hexadecimal
digits).
-nwkey- Disable WEP encryption.
nwkey
persist- Enable WEP encryption using the persistent key stored in the network
card.
nwkey
persist:key- Write key to the persistent memory of the network
card, and enable WEP encryption using that key.
powersave- Enable 802.11 power saving mode. Power saving is disabled by default. See
driver specific manual pages to see details of the implementation relevant
to that device.
-powersave- Disable 802.11 power saving mode.
scan- Show the results of an access point scan. In Host AP mode, this will dump
the list of known nodes without scanning. In station mode, this will list
each access point's SSID, channel, MAC address (BSSID), received signal
strength indicator, maximum data transfer rate, and supported feature
flags. If an access point cannot be selected due to incompatibilities with
the interface configuration,
ifconfig indicates
mismatching configuration items with an exclamation mark.
Because the list of access points is continuously updated
while a scan is in progress, scan may sometimes
show incomplete scan results.
Some interfaces support scanning in the background while
remaining associated to the current access point. The superuser may use
scan to trigger a background scan while
associated, which will update the scan result list and also trigger a
search for a better access point to roam to.
wpa- Enable Wi-Fi Protected Access. WPA is a Wi-Fi Alliance protocol based on
the IEEE 802.11i standard. It was designed to enhance the security of
wireless networks. Notice that not all drivers support WPA. Check the
driver's manual page to know if this option is supported.
-wpa- Disable Wi-Fi Protected Access.
wpaakms
akm,akm,...- Set the comma-separated list of allowed authentication and key management
protocols.
The supported values are “psk” and
“802.1x”. psk authentication (also
known as personal mode) uses a 256-bit pre-shared key.
802.1x authentication (also known as enterprise
mode) is used with an external IEEE 802.1X authentication server, such
as wpa_supplicant. The default value is “psk”.
“psk” can only be used if a pre-shared key is configured
using the wpakey option.
wpaciphers
cipher,cipher,...- Set the comma-separated list of allowed pairwise ciphers.
The supported values are “tkip”,
“ccmp”, and “usegroup”.
usegroup specifies that no pairwise ciphers are
supported and that only group keys should be used. The default value is
“ccmp”. If multiple pairwise ciphers are specified, the
pairwise cipher will be negotiated between the station and the access
point at association time. A station will always try to use
ccmp over tkip if both
ciphers are allowed and supported by the access point. If the selected
cipher is not supported by the hardware, software encryption will be
used. Check the driver's manual page to know which ciphers are supported
in hardware.
wpagroupcipher
cipher- Set the group cipher used to encrypt broadcast and multicast traffic.
The supported values are “wep40”,
“wep104”, “tkip”, and “ccmp”.
The default value is “ccmp”. The use of
tkip or wep40 or
wep104 as the group cipher is discouraged due to
weaknesses in TKIP and WEP. The wpagroupcipher
option is available in Host AP mode only. A station will always use the
group cipher of the BSS.
wpakey
passphrase | hexkey- Set the WPA key and enable WPA. The key can be given using either a
passphrase or a full length hex key, starting with 0x. If a passphrase is
used the
nwid or join
option must first be specified, since ifconfig
will hash the nwid along with the passphrase to create the key.
-wpakey- Delete the pre-shared WPA key and disable WPA.
wpaprotos
proto,proto,...- Set the comma-separated list of allowed WPA protocol versions.
The supported values are “wpa1” and
“wpa2”. wpa1 is based on draft 3 of
the IEEE 802.11i standard whereas wpa2 is based on
the ratified standard. The default value is “wpa2”. If
“wpa1,wpa2” is specified, a station will always use the
wpa2 protocol when supported by the access
point.
ifconfig |
interface inet6
[[-]anycast]
[[-]temporary]
[eui64]
[pltime n]
[[-]soii]
[[-]tentative]
[vltime n] |
The following options are available for an
ip6(4) interface:
anycast- Set the IPv6 anycast address bit.
-anycast- Clear the IPv6 anycast address bit.
temporary- Enable temporary address extensions for stateless IPv6 address
autoconfiguration (RFC 8981) on the interface. These extensions are
enabled by default. The purpose of these extensions is to prevent tracking
of individual devices which connect to the IPv6 internet from different
networks using stateless autoconfiguration. The interface identifier often
remains constant and provides the lower 64 bits of an autoconfigured IPv6
address, facilitating tracking of individual devices (and hence,
potentially, users of these devices) over long periods of time (weeks to
months to years). When these extensions are active, random interface
identifiers are used for autoconfigured addresses.
Autoconfigured addresses are also made temporary, which means
that they will automatically be replaced regularly. Temporary addresses
are deprecated after 24 hours. Once a temporary address has been
deprecated, a new temporary address will be configured upon reception of
a router advertisement indicating that the prefix is still valid.
Deprecated addresses will not be used for new connections as long as a
non-deprecated address remains available. Temporary addresses become
invalid after another 24 hours, at which time they will be removed from
the interface.
-temporary- Disable IPv6 autoconf temporary address extensions on the interface.
Currently configured addresses will not be removed until they become
invalid.
eui64- Fill the interface index (the lowermost 64 bits of an IPv6 address)
automatically.
pltime
n- Set preferred lifetime for the address, in seconds.
soii- Enable persistent Semantically Opaque Interface Identifiers (SOIIs), as
per RFC 7217, for SLAAC addresses on the interface. The purpose of these
identifiers is to make discovery of hosts by scanning a whole prefix more
difficult. SOIIs use the whole 64 bits of the host part while SLAAC
addresses are formed from MAC addresses which can lower the entropy to 24
bits if the host is running in a virtualization environment or the
hardware manufacturer is known. See RFC 7721 and RFC 8064 for details.
SOIIs are enabled by default.
-soii- Disable IPv6 persistent Semantically Opaque Interface Identifiers on the
interface. Currently configured addresses will not be removed until they
become invalid.
tentative- Set the IPv6 tentative address bit.
-tentative- Clear the IPv6 tentative address bit.
vltime
n- Set valid lifetime for the address, in seconds.
ifconfig -g
group-name
[[-]carpdemote
[number]]
The following options are available for interface groups:
-g
group-name- Specify the group.
carpdemote
[number]- Increase carp(4) demotion counter for
given interface group by number. Acceptable values
are 0 to 128. If number is omitted, it is increased
by 1. The maximum value for a demotion counter is 255.
-carpdemote
[number]- Decrease carp(4) demotion counter for
given interface group by number. Acceptable values
are 0 to 128. If number is omitted, it is decreased
by 1.
ifconfig |
mpls-interface
[[-]mplslabel mpls-label]
[[-]pwecw]
[[-]pwefat]
[pweneighbor mpls-label neighbor]
[[-]tunneldomain rdomain] |
The following options are available for
mpe(4),
mpip(4), and
mpw(4) interfaces:
mplslabel
mpls-label- Set the local MPLS label to mpls-label. MPLS packets
sent to this label on the local system will be decapsulated for input. An
MPLS label is a 20-bit number. Labels 0 to 15 inclusive are reserved
labels and cannot be used.
-mplslabel- Unset the local MPLS label.
tunneldomain
rdomain- Use the routing domain rdomain for MPLS transit. The
MPLS encapsulated traffic does not need to terminate in the same routing
domain as the interface itself.
-tunneldomain- Use the default routing domain 0 for MPLS transit.
The following options are available for the
mpip(4) and
mpw(4) interfaces that provide MPLS
Pseudowire Emulation Edge-to-Edge (PWE3) functionality:
pwecw- Enable the use of the PWE3 Control Word.
-pwecw- Disable the use of the PWE3 Control Word.
pwefat- Enable the use of the Flow-Aware Transport (FAT) flow label.
-pwefat- Disable the use of the Flow-Aware Transport (FAT) flow label.
pweneighbor
mpls-label neighbor- Use mpls-label and neighbor as
the remote MPLS label and neighbor respectively. Remote MPLS labels have
the same restrictions on values as local MPLS labels.
ifconfig |
pair-interface
[[-]patch interface] |
The following options are available for a
pair(4) interface:
patch
interface- Connect the interface with a second
pair(4) interface. Any outgoing packets
from the first pair-interface will be received by
the second interface, and vice versa. This makes it
possible to interconnect two routing domains locally.
-patch- If configured, disconnect the interface pair.
ifconfig |
pflow-interface
[[-]flowdst addr:port]
[[-]flowsrc addr[:port]]
[pflowproto n] |
The following options are available for a
pflow(4) interface:
flowdst
addr:port- Set the receiver address and the port for
pflow(4) packets. Both must be defined
to export pflow data. addr is the IP address and
port is the port number of the flow collector. Pflow
data will be sent to this address/port.
-flowdst- Unset the receiver address and stop sending pflow data.
flowsrc
addr[:port]- Set the source IP address for pflow packets. addr is
the IP address used as sender of the UDP packets and may be used to
identify the source of the data on the pflow collector.
-flowsrc- Unset the source address.
pflowproto
n- Set the protocol version. The default is version 5.
ifconfig |
pfsync-interface
[[-]defer]
[maxupd n]
[[-]syncdev iface]
[[-]syncpeer peer_address] |
The following options are available for a
pfsync(4) interface:
defer- Defer transmission of the first packet in a state until a peer has
acknowledged that the associated state has been inserted. See
pfsync(4) for more information.
-defer- Do not defer the first packet in a state. This is the default.
maxupd
n- Indicate the maximum number of updates for a single state which can be
collapsed into one. This is an 8-bit number; the default value is
128.
syncdev
iface- Use the specified interface to send and receive pfsync state
synchronisation messages.
-syncdev- Stop sending pfsync state synchronisation messages over the network.
syncpeer
peer_address- Make the pfsync link point-to-point rather than using multicast to
broadcast the state synchronisation messages. The peer_address is the IP
address of the other host taking part in the pfsync cluster. With this
option, pfsync(4) traffic can be
protected using ipsec(4).
-syncpeer- Broadcast the packets using multicast.
ifconfig |
pppoe-interface
[authkey key]
[authname name]
[authproto proto]
[[-]peerflag flag]
[peerkey key]
[peername name]
[peerproto proto]
[[-]pppoeac access-concentrator]
[pppoedev parent-interface]
[[-]pppoesvc service] |
pppoe(4) uses the
sppp(4) "generic" SPPP framework.
Any options not described in the section immediately following are described
in the SPPP section, below.
The following options are available for a
pppoe(4) interface:
pppoeac
access-concentrator- Set the name of the access-concentrator.
-pppoeac- Clear a previously set access-concentrator name.
pppoedev
parent-interface- Set the name of the interface through which packets will be transmitted
and received.
pppoesvc
service- Set the service name of the interface.
-pppoesvc- Clear a previously set service name.
ifconfig |
sppp-interface
[authkey key]
[authname name]
[authproto proto]
[[-]peerflag flag]
[peerkey key]
[peername name]
[peerproto proto] |
The following options are available for an
sppp(4) or
pppoe(4) interface:
authkey
key- Set the client key or password for the PPP authentication protocol.
authname
name- Set the client name for the PPP authentication protocol.
authproto
proto- Set the PPP authentication protocol on the specified interface acting as a
client. The protocol name can be either
‘
chap’,
‘pap’, or
‘none’. In the latter case,
authentication will be turned off.
peerflag
flag- Set a specified PPP flag for the remote authenticator. The flag name can
be either ‘
callin’ or
‘norechallenge’. The
‘callin’ flag will require the
remote peer to authenticate only when he's calling in, but not when the
peer is called by the local client. This is required for some peers that
do not implement the authentication protocols symmetrically. The
‘norechallenge’ flag is only
meaningful with the CHAP protocol to not re-challenge once the initial
CHAP handshake has been successful. This is used to work around broken
peer implementations that can't grok being re-challenged once the
connection is up.
-peerflag
flag- Remove a specified PPP flag for the remote authenticator.
peerkey
key- Set the authenticator key or password for the PPP authentication
protocol.
peername
name- Set the authenticator name for the PPP authentication protocol.
peerproto
proto- Set the PPP authentication protocol on the specified interface acting as
an authenticator. The protocol name can be either
‘
chap’,
‘pap’, or
‘none’. In the latter case,
authentication will be turned off.
The following options are available for a
switch(4) interface:
add
interface- Add interface as a member of the switch. The
interface is put into promiscuous mode so that it can receive every packet
sent on the network. An interface can be a member of at most one
switch.
addlocal
interface- Add interface as a local port of the switch. Local
port is a special port connected with the local system's network stack.
Only vether(4) can be used for the
interface. Only one interface can be added as a
local port.
datapath
id- Configure the datapath ID for the switch. The default value is generated
randomly.
del
interface- Remove interface from the switch. Promiscuous mode
is turned off for the interface when it is removed from the switch.
maxflow
number- Set the maximum number of flows per table. The default value is
10000.
maxgroup
number- Set the maximum number of groups. The default value is 1000.
portno
interface number- Set the port number for the port named interface.
The default value is the interface index of the
interface.
protected
interface ids- Put interface in protected domains.
ids is a comma delimited list of domain IDs, between
1 and 31, to put the interface in. Interfaces that are part of a protected
domain cannot forward traffic to any other interface in that domain.
Interfaces do not belong to any protected domain by default.
-protected
interface- Remove interface from all protected domains.
up- Start the switch processing packets.
ifconfig |
tpmr-interface
[add child-iface]
[del child-iface]
[[-]link0]
[[-]link1]
[[-]link2] |
The following options are available for a
tpmr(4) interface:
add
child-iface- Add child-iface as a member.
del
child-iface- Remove the member child-iface.
link0- Disable the filtering of Ethernet frames destined for the TPMR component
reserved addresses, as specified by IEEE 802.1Q.
-link0- Enable the filtering of Ethernet frames destined for the TPMR component
reserved addresses, as specified by IEEE 802.1Q. This is the default.
link1- Disable the filtering of IPv4 and IPv6 packets with
pf(4).
-link1- Enable the filtering of IPv4 and IPv6 packets with
pf(4). This is the default.
link2- Disable the filtering of 802.1Q VLAN and QinQ SVLAN packets.
-link2- Enable the filtering of 802.1Q VLAN and QinQ SVLAN packets. This is the
default.
ifconfig |
trunk-interface
[lacpmode active|passive]
[lacptimeout fast|slow]
[[-]trunkport child-iface]
[trunkproto proto] |
The following options are available for
aggr(4) and
trunk(4) interfaces:
lacpmode
active|passive- Set the LACP trunk mode to either
active (default)
or passive.
lacptimeout
fast|slow- Set the LACP timeout speed to either
fast or
slow (default).
trunkport
child-iface- Add child-iface as a trunk port.
-trunkport
child-iface- Remove the trunk port child-iface.
trunkproto
proto- Set the link aggregation protocol on
trunk(4) interfaces. Refer to
trunk(4) for a complete list of the
available protocols.
ifconfig |
tunnel-interface
[[-]keepalive period count]
[rxprio prio]
[[-]tunnel src_address dest_address]
[[-]tunneldf]
[[-]tunneldomain rtable]
[tunnelttl ttl]
[txprio prio]
[[-]vnetflowid]
[[-]vnetid network-id] |
egre(4),
eoip(4),
etherip(4),
gif(4),
gre(4),
mgre(4),
nvgre(4), and
vxlan(4) are all tunnel interfaces. The
following options are available:
keepalive
period count- Enable gre(4) keepalive with a packet sent
every period seconds. A second timer is run with a
timeout of count * period. If
no keepalive response is received during that time, the link is considered
down. The minimal usable count is 2 since the
round-trip time of keepalive packets needs to be accounted for.
-keepalive- Disable the gre(4) keepalive
mechanism.
rxprio
prio- Configure the source used for the packet priority when decapsulating a
packet. The value can be a priority number from 0 to 7, or
packet to use the priority currently set on the
packet. If supported by the interface, the value may also be set to
outer to have the priority field copied from the
tunnel protocol headers, or payload to have the
priority field copied from the encapsulated protocol headers.
tunnel
src_address
dest_address[:dest_port]- Set the source and destination tunnel addresses on a tunnel interface.
Packets routed to this interface will be encapsulated in IPv4 or IPv6,
depending on the source and destination address families. Both addresses
must be of the same family. The optional destination port can be specified
for interfaces such as vxlan(4), which
further encapsulate the packets in UDP datagrams.
-tunnel- Remove the source and destination tunnel addresses.
tunneldf- Do not allow fragmentation of encapsulated packets.
-tunneldf- Allow fragmentation of encapsulated packets.
tunneldomain
rtable- Use routing table rtable instead of the default
table. The tunnel does not need to terminate in the same routing domain as
the interface itself. rtable can be set to any valid
routing table ID; the corresponding routing domain is derived from this
table.
-tunneldomain- Use the default routing table and routing domain 0.
tunnelttl
ttl- Set the IP or multicast TTL of the tunnel packets. If supported by the
tunnel protocol, the value can also be set to copy
to have the TTL copied between the encapsulated protocol headers and the
tunnel protocol headers.
txprio
prio- Configure the value used for the priority field in the tunnel protocol
headers. The value can be a priority number from 0 to 7, or
packet to use the priority currently set on the
packet. If supported by the interface, the value can also be set to
payload to have the priority field copied from the
encapsulated protocol headers to the tunnel protocol headers.
vnetflowid- Use a portion of the virtual network identifier space for a flow
identifier. This allows load balancing of the encapsulated traffic over
multiple links.
-vnetflowid- Disable the use of a flow identifier in the virtual network
identifier.
vnetid
network-id- Set the virtual network identifier. This is a number which is used by
tunnel protocols such as eoip(4) and
vxlan(4) to identify packets with a
virtual network. The accepted size of the number depends on the individual
tunnel protocol; it is a 16-bit number for
eoip(4), and a 24-bit number for
vxlan(4). If supported by the tunnel
protocol, the value can also be set to any to accept
packets with arbitrary network identifiers (for example for
multipoint-to-multipoint modes).
-vnetid- Clear the virtual network identifier.
ifconfig |
umb-interface
[[-]apn apn]
[chgpin oldpin newpin]
[[-]class class,class,...]
[pin pin]
[puk puk newpin]
[[-]roaming] |
The following options are available for a
umb(4) interface:
apn
apn- Set the Access Point Name (APN) required by the network provider.
-apn- Clear the current APN.
chgpin
oldpin newpin- Permanently change the PIN of the SIM card from the current value
oldpin to newpin.
class- List all available cell classes.
class
class,class,...- Set the preferred cell classes. Apart from those listed by
class the following aliases can be used:
4G, 3G, and
2G.
-class- Clear any cell class preferences.
down- Marking the interface as "down" will terminate any existing data
connection and deregister with the service provider.
pin
pin- Enter the PIN required to unlock the SIM card. Most SIM cards will not be
able to establish a network association without providing a PIN.
puk
puk newpin- Sets the PIN of the SIM card to newpin using the PUK
puk to validate the request.
roaming- Enable data roaming.
-roaming- Disable data roaming.
up- As soon as the interface is marked as "up", the
umb(4) device will try to establish a data
connection with the service provider.
ifconfig |
veb-interface
[add child-iface]
[addspan child-iface]
[del child-iface]
[delspan child-iface]
[[-]discover child-iface]
[[-]learn child-iface]
[[-]link0]
[[-]link1]
[[-]protected child-iface ids] |
The following options are available for a
veb(4) interface:
add
child-iface- Add child-iface as a member.
addspan
child-iface- Add child-iface as a span port on the bridge.
del
child-iface- Remove the member child-iface.
delspan
child-iface- Delete child-iface from the list of span ports of
the bridge.
discover
child-iface- Mark child-iface so that packets are sent out of the
interface if the destination port of the packet is unknown. If the bridge
has no address cache entry for the destination of a packet, meaning that
there is no static entry and no dynamically learned entry for the
destination, the bridge will forward the packet to all member interfaces
that have this flag set. This is the default for interfaces added to the
bridge.
-discover
child-iface- Mark child-iface so that packets are not sent out of
the interface if the destination port of the packet is unknown. Turning
this flag off means that the bridge will not send packets out of this
interface unless the packet is a broadcast packet, multicast packet, or a
packet with a destination address found on the interface's segment. This,
in combination with static address cache entries, prevents potentially
sensitive packets from being sent on segments that have no need to see the
packet.
learn
child-iface- Mark child-iface so that the source address of
packets received from the interface are entered into the address cache.
This is the default for interfaces added to the bridge.
-learn
child-iface- Mark child-iface so that the source address of
packets received from interface are not entered into the address
cache.
link0- Disable the filtering of 802.1Q VLAN and QinQ SVLAN packets.
-link0- Enable the filtering of 802.1Q VLAN and QinQ SVLAN packets. This is the
default.
link1- Enable the filtering of IPv4 and IPv6 packets with
pf(4).
-link1- Disable the filtering of IPv4 and IPv6 packets with
pf(4). This is the default.
protected
child-iface ids- Put interface in protected domains.
ids is a comma delimited list of domain IDs, between
1 and 31, to put the interface in. Interfaces that are part of a protected
domain cannot forward traffic to any other interface in that domain.
Interfaces do not belong to any protected domain by default.
-protected
child-iface- Remove child-iface from all protected domains.
ifconfig |
vlan-interface
[[-]parent parent-interface]
[rxprio prio]
[txprio prio]
[[-]vnetid vlan-tag] |
The following options are available for
vlan(4) and
svlan(4) VLAN interfaces:
parent
parent-interface- Associate the VLAN interface with the interface
parent-interface. Packets transmitted on
vlan(4) or
svlan(4) interfaces will be tagged with
802.1Q or 802.1ad headers respectively and transmitted on the specified
parent interface. Packets with 802.1Q or 802.1ad tags received by the
parent interface with the specified VLAN tag will be diverted to the
associated VLAN interface. Unless a custom Ethernet address is assigned to
the VLAN interface, it will inherit a copy of the parent interface's
Ethernet address.
-parent- Disassociate from the parent interface. This breaks the link between the
VLAN interface and its parent.
rxprio
prio- Set the value used for the packet priority field. Values may be from 0 to
7, packet to maintain the current packet priority,
or outer to use the priority field in the 802.1Q or
802.1ad headers.
txprio
prio- Set the value used for the priority field in the 802.1Q or 802.1ad
headers. Values may be from 0 to 7, or packet to use
the priority of packets transmitted on the interface.
vnetid
vlan-tag- Set the VLAN tag value to vlan-tag. This value is a
12-bit number which is used in the 802.1Q or 802.1ad headers in packets
handled by vlan(4) or
svlan(4) interfaces respectively. Valid
tag values are from 1 to 4094 inclusive.
-vnetid- Clear the tag value. Packets on a VLAN interface without a tag set will
use a value of 0 in their headers.
ifconfig |
wg-interface
[wgkey privatekey]
[wgport port]
[wgrtable rtable]
[-wgpeerall]
[[-]wgpeer
publickey
[wgaip allowed-ip_address/prefix]
[wgendpoint peer_address port]
[wgpka interval]
[wgpsk presharedkey]
[-wgpsk]] |
The following options are available for
wg(4) interfaces:
wgkey
privatekey- Set the private key of the interface. The privatekey
is 32 bytes, base64-encoded. It can be generated as follows:
$ openssl rand -base64
32
The corresponding public key will then be displayed in the
interface status for distribution to peers.
wgpeer
publickey- Specify an interface peer by its publickey, which is
32 bytes, base64-encoded. Repeat the option to specify multiple peers in a
single command.
-wgpeer
publickey- Remove the peer with the given publickey.
-wgpeerall- Remove all peers from the interface.
wgport
port- Set the interface's UDP port for exchanging traffic
with its peers. The interface will bind to
INADDR_ANY and
IN6ADDR_ANY_INIT. By default, the interface will
choose a port.
wgrtable
rtable- Exchange traffic with peers under the routing table
rtable, instead of the default
rtable(4). The routing domain of the
rtable needn't be the routing domain to which the
interface is attached, in which the interface's tunneled traffic
appears.
Peer configuration options, which apply to the
wgpeer immediately preceding them, are as
follows:
wgaip
allowed-ip_address/prefix- Set the peer's IPv4 or IPv6 allowed-ip_address range
for tunneled traffic. Repeat the option to set multiple ranges. By
default, no addresses are allowed.
wgendpoint
peer_address port- Address traffic to the peer's IPv4 or IPv6
peer_address and UDP port. The
interface will track the peer, updating
wgendpoint
to the source of its last authenticated packet. By default, the endpoint
is unknown and so the peer cannot be addressed until it initiates
communication. This implies that at least one peer in each pair must
specify wgendpoint.
wgpka
interval- Set the interval of persistent keepalive packets in
seconds. The default, zero, disables these. They can be used to maintain
connectivity to a peer otherwise blocked to unsolicited traffic by an
intermediate firewall or NAT device. For this, an
interval of 25 seconds should suffice.
wgpsk
presharedkey- Set a unique key pre-shared with the peer. This strengthens the
Diffie-Hellman exchange should in future a quantum-computational attack on
it become feasible. The presharedkey is 32 bytes,
base64-encoded. It is optional but recommended and can be generated as
follows:
$ openssl rand -base64
32
-wgpsk- Remove the pre-shared key for this peer.
Assign the address of 192.168.1.10 with a network mask of
255.255.255.0 to interface fxp0:
# ifconfig fxp0 inet 192.168.1.10
netmask 255.255.255.0
Configure the xl0 interface to use 100baseTX, full duplex:
# ifconfig xl0 media 100baseTX
mediaopt full-duplex
Label the em0 interface as an uplink:
# ifconfig em0 description
"Uplink to Gigabit Switch 2"
Create the gif1 network interface:
# ifconfig gif1 create
Put the athn0 wireless interface into monitor mode:
# ifconfig athn0 mediaopt
monitor
Messages indicating the specified interface does not exist, the
requested address is unknown, or the user is not privileged and tried to
alter an interface's configuration.
netstat(1),
ifmedia(4),
inet(4),
intro(4),
netintro(4),
route(4),
rtable(4),
hostname.if(5),
hosts(5),
rc(8),
slaacd(8),
tcpdump(8)
The ifconfig command appeared in
4.2BSD.