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IFMEDIA(4)	       FreeBSD Kernel Interfaces Manual		    IFMEDIA(4)

NAME
     ifmedia --	network	interface media	settings

SYNOPSIS
     #include <sys/socket.h>
     #include <net/if.h>
     #include <net/if_media.h>

DESCRIPTION
     The ifmedia interface provides a consistent method	for querying and set-
     ting network interface media and media options.  The media	is typically
     set using the ifconfig(8) command.

     Currently these link types	are supported by ifmedia:

	   IFM_ETHER	  Ethernet
	   IFM_FDDI	  FDDI
	   IFM_IEEE80211  IEEE802.11 Wireless LAN
	   IFM_TDM	  Time Division	Multiplex
	   IFM_CARP	  CARP

     The following sections describe the possible media	settings for each link
     type.  Not	all of these are supported by every device; refer to your de-
     vice's manual page	for more information.

     The lists below provide the possible names	of each	media type or option.
     The first name in the list	is the canonical name of the media type	or op-
     tion.  Additional names are acceptable aliases for	the media type or op-
     tion.

COMMON MEDIA TYPES AND OPTIONS
     The following media types are shared by all link types:

	   IFM_AUTO    Autoselect the best media.  [autoselect,	auto]
	   IFM_MANUAL  Jumper or switch	on device selects media.  [manual]
	   IFM_NONE    Deselect	all media.  [none]

     The following media options are shared by all link	types:

	   IFM_FDX    Place the	device into full-duplex	mode.  This option
		      only has meaning if the device is	normally not full-du-
		      plex.

	   IFM_HDX    Place the	device into half-duplex	mode.  This option
		      only has meaning if the device is	normally not half-du-
		      plex.  [half-duplex, hdx]

	   IFM_FLOW   Enable hardware flow control on device.

	   IFM_FLAG0  Driver-defined flag.  [flag0]

	   IFM_FLAG1  Driver-defined flag.  [flag1]

	   IFM_FLAG2  Driver-defined flag.  [flag2]

	   IFM_LOOP   Place the	device into hardware loopback mode.  [loop-
		      back, hw-loopback, loop]

MEDIA TYPES AND	OPTIONS	FOR ETHERNET
     The following media types are defined for Ethernet:

	   IFM_10_T	   10BASE-T, 10Mb/s over unshielded twisted pair, RJ45
			   connector.  [10baseT, UTP, 10UTP]

	   IFM_10_2	   10BASE2, 10Mb/s over	coaxial	cable, BNC connector;
			   also	called Thinnet.	 [10base2, BNC,	10BNC]

	   IFM_10_5	   10BASE5, 10Mb/s over	15-wire	cables,	DB15 connec-
			   tor;	also called AUI.  [10base5, AUI, 10AUI]

	   IFM_10_STP	   10BASE-STP, 10Mb/s over shielded twisted pair, DB9
			   connector.  [10baseSTP, STP,	10STP]

	   IFM_10_FL	   10BASE-FL, 10Mb/s over fiber	optic cables.
			   [10baseFL, FL, 10FL]

	   IFM_100_TX	   100BASE-TX, 100Mb/s over unshielded twisted pair,
			   RJ45	connector.  [100baseTX,	100TX]

	   IFM_100_FX	   100BASE-FX, 100Mb/s over fiber optic	cables.
			   [100baseFX, 100FX]

	   IFM_100_T4	   100BASE-T4, 100Mb/s over 4-wire (category 3)	un-
			   shielded twisted pair, RJ45 connector.  [100baseT4,
			   100T4]

	   IFM_100_T2	   100BASE-T2.	[100baseT2, 100T2]

	   IFM_100_VG	   100VG-AnyLAN.  [100baseVG, 100VG]

	   IFM_1000_SX	   1000BASE-SX,	1Gb/s over multi-mode fiber optic ca-
			   bles.  [1000baseSX, 1000SX]

	   IFM_1000_LX	   1000BASE-LX,	1Gb/s over single-mode fiber optic ca-
			   bles.  [1000baseLX, 1000LX]

	   IFM_1000_CX	   1000BASE-CX,	1Gb/s over shielded twisted pair.
			   [1000baseCX,	1000CX]

	   IFM_1000_T	   1000BASE-T, 1Gb/s over category 5 unshielded
			   twisted pair, RJ45 connector.  [1000baseT, 1000T]

	   IFM_1000_TX	   Compatibility for 1000BASE-T.  [1000baseTX, 1000TX]

	   IFM_2500_SX	   2500BASE-SX,	2.5Gb/s	over multi-mode	fiber optic
			   cables.  [2500baseSX, 2500SX]

	   IFM_2500_T	   2500BASE-T, 2.5Gb/s over unshielded twisted pair,
			   RJ45	connector.  [2500baseT,	2500BASE-T]

	   IFM_10G_CX4	   10GBASE-CX4,	10Gb/s over XAUI 4-lane	PCS and	copper
			   cables.  [10GbaseCX4, 10GCX4, 10GBASE-CX4]

	   IFM_10G_LR	   10GBASE-LR, 10Gb/s over single-mode fiber optic ca-
			   bles.  [10GbaseLR, 10GLR, 10GBASE-LR]

	   IFM_10G_SFP_CU  10GSFP+Cu, 10Gb/s over SFP+ Direct Attach cables.
			   [10GSFP+Cu, 10GCu]

	   IFM_10G_SR	   10GBASE-SR, 10Gb/s over multi-mode fiber optic ca-
			   bles.  [10GbaseSR, 10GSR, 10GBASE-SR]

	   IFM_10G_T	   10GBASE-T, 10Gb/s over unshielded twisted pair,
			   RJ45	connector.  [10GbaseT, 10GT, 10GBASE-T]

	   IFM_HPNA_1	   HomePNA 1.0,	1Mb/s over 2-wire (category 3) un-
			   shielded twisted pair [HomePNA1, HPNA1]

     The following media options are defined for Ethernet:

	   IFM_ETH_MASTER   Configure a	1000BASE-T PHY as a MASTER PHY.

	   IFM_ETH_RXPAUSE  Receive flow control is enabled on the 1000BASE-T
			    PHY.

	   IFM_ETH_TXPAUSE  Transmit flow control is enabled on	the 1000BASE-T
			    PHY.

MEDIA TYPES AND	OPTIONS	FOR FDDI
     The following media types are defined for FDDI:

	   IFM_FDDI_SMF	 Single-mode fiber.  [Single-mode, SMF]
	   IFM_FDDI_MMF	 Multi-mode fiber.  [Multi-mode, MMF]
	   IFM_FDDI_UTP	 Unshielded twisted pair, RJ45 connector.  [UTP, CDDI]

     The following media options are defined for FDDI:

	   IFM_FDDI_DA	Dual-attached station vs. Single-attached station.
			[dual-attach, das]

MEDIA TYPES AND	OPTIONS	FOR IEEE802.11 WIRELESS	LAN
     The following media modes are defined for IEEE802.11 Wireless LAN:

	   IFM_IEEE80211_11A   5GHz, OFDM mode.	 [11a]
	   IFM_IEEE80211_11B   2GHz, DSSS/CCK mode.  [11b]
	   IFM_IEEE80211_11G   2GHz, DSSS/CCK/OFDM mode.  [11g]
	   IFM_IEEE80211_FH    2GHz, GFSK mode.	 [fh]
	   IFM_IEEE80211_11N   2GHz/5GHz, HT mode.  [11n]
	   IFM_IEEE80211_11AC  5GHz, VHT mode.	[11ac]

     The following media options are defined for IEEE802.11 Wireless LAN:

	   IFM_IEEE80211_ADHOC	     Ad-hoc mode.  [adhoc]
	   IFM_IEEE80211_HOSTAP	     Host Access Point mode.  [hostap]
	   IFM_IEEE80211_IBSS	     IBSS mode.	 [ibss]
	   IFM_IEEE80211_IBSSMASTER  IBSS master mode.	[ibssmaster]
	   IFM_IEEE80211_MONITOR     Monitor mode.  [monitor]

     All of the	above media options are	mutually exclusive.  If	no media op-
     tion is used, the wireless	interface will try to find an access point to
     connect to.  hostap mode allows the wireless interface to act as an ac-
     cess point	for other 802.11 devices.  ibss	mode is	the standardized
     method of operating without an access point, with each participating de-
     vice taking on part of the	role of	an access point.  adhoc	mode, more ac-
     curately known as ad-hoc demo mode, is not	specified by the IEEE 802.11
     standard and only works with wi(4)	devices.  Likewise, ibssmaster mode
     only works	with wi(4) devices.  On	standard 802.11	networks the IBSS mas-
     ter role is assigned automatically.

     The channels detailed below are defined for IEEE802.11 Wireless LAN in
     the 2.4GHz	band.  The list	of available frequencies is dependent on radio
     regulations specified by regional authorities.  Recognized	regulatory au-
     thorities include the FCC (United States),	ETSI (Europe), and Japan.
     Frequencies in the	table are specified in MHz.

	   Channel     FCC     ETSI    Japan
	   1	       2412    2412    2412
	   2	       2417    2417    2417
	   3	       2422    2422    2422
	   4	       2427    2427    2427
	   5	       2432    2432    2432
	   6	       2437    2437    2437
	   7	       2442    2442    2442
	   8	       2447    2447    2447
	   9	       2452    2452    2452
	   10	       2457    2457    2457
	   11	       2462    2462    2462
	   12	       -       2467    2467
	   13	       -       2472    2472
	   14	       -       -       2484

     The channels do overlap; the bandwidth required for each channel is about
     20MHz.  When using	multiple channels in close proximity it	is suggested
     that channels be separated	by at least 25MHz.  In the US, this means that
     only channels 1, 6, and 11	may be used simultaneously without interfer-
     ence.

     Channels in the 5GHz band are too numerous	to list	here.  Regulation of
     their use,	particularly outdoors, varies between countries.  Users	are
     advised to	inform themselves about	applicable regulations before config-
     uring wireless LAN	devices	for use	in the 5GHz band.

     The following media types are defined for IEEE802.11 Wireless LAN:

	   IFM_IEEE80211_FH1  Frequency	Hopping	1Mbps.	[FH1]
	   IFM_IEEE80211_FH2  Frequency	Hopping	2Mbps.	[FH2]
	   IFM_IEEE80211_DS1  Direct Sequence 1Mbps.  [DS1]
	   IFM_IEEE80211_DS2  Direct Sequence 2Mbps.  [DS2]

     The above media types were	first introduced in the	IEEE 802.11-1997 stan-
     dard and are used in the 2.4GHz band only.	 Frequency Hopping Spread
     Spectrum modulation is incompatible with modern 802.11 networks.  Direct
     Sequence Spread Spectrum modulation (DSSS)	frames can still be used if
     backwards compatibility to	802.11b	is enabled.

	   IFM_IEEE80211_DS5   Direct Sequence 5.5Mbps.	 [DS5]
	   IFM_IEEE80211_DS11  Direct Sequence 11Mbps.	[DS11]
	   IFM_IEEE80211_DS22  Direct Sequence 22Mbps.	[DS22]

     The above media types were	first introduced in the	IEEE 802.11b-1999
     standard and are used in the 2.4GHz band only.  They use Complementary
     Code Keying (CCK) which, compared to frames sent at 1Mbps or 2Mbps, re-
     duces the possible	distance between transmitter and receiver.

     Modern 802.11 networks remain compatible with 802.11b, even though	DSSS
     frames are	incompatible with modern 802.11	frames using OFDM.  Co-exis-
     tence with	802.11b	requires OFDM transmitters to either risk frame	colli-
     sions or "reserve"	the medium with	a separate preceding transmission that
     DSSS receivers are	able to	decode.	 This causes additional	overhead which
     some 802.11 deployments avoid by deliberately disabling backwards compat-
     ibility with 802.11b.

	   IFM_IEEE80211_OFDM6	   OFDM	6Mbps.	[OFDM6]
	   IFM_IEEE80211_OFDM9	   OFDM	9Mbps.	[OFDM9]
	   IFM_IEEE80211_OFDM12	   OFDM	12Mbps.	 [OFDM12]
	   IFM_IEEE80211_OFDM18	   OFDM	18Mbps.	 [OFDM18]
	   IFM_IEEE80211_OFDM24	   OFDM	24Mbps.	 [OFDM24]
	   IFM_IEEE80211_OFDM36	   OFDM	36Mbps.	 [OFDM36]
	   IFM_IEEE80211_OFDM48	   OFDM	48Mbps.	 [OFDM48]
	   IFM_IEEE80211_OFDM54	   OFDM	54Mbps.	 [OFDM54]
	   IFM_IEEE80211_OFDM72	   OFDM	72Mbps.	 [OFDM72]

     The above media types were	first introduced in the	IEEE 802.11a-1999
     standard for the 5GHz band, and in	the IEEE 802.11g-2003 standard for the
     2.4GHz band.  OFDM	with 72Mbps is a proprietary extension and was never
     standardized by IEEE.

     Orthogonal	Frequency Division Multiplexing	(OFDM) is the current standard
     modulation	technique for 802.11.  Each 20MHz channel used by 802.11a and
     802.11g provides space for	48 OFDM	sub-carriers for data.	The sub-carri-
     ers use BPSK, QPSK, 16QAM,	or 64QAM modulation, combined with a particu-
     lar coding	rate for error correction at the receiver.  The	coding rate
     specifies how many	data bits in a frame are transmitted without redun-
     dancy.

	   Modulation	 Coding	Rate	 Mbit/s
	   BPSK		 1/2		 6
	   BPSK		 3/4		 9
	   QPSK		 1/2		 12
	   QPSK		 3/4		 18
	   16QAM	 1/2		 24
	   16QAM	 3/4		 36
	   64QAM	 1/2		 48
	   64QAM	 3/4		 52

     The IEEE 802.11n-2009 standard for	"High Throughput" (HT) wireless	LAN
     defines additional	sub-carriers, modulations, and coding rates.  The
     channel bandwidth for data	frame transmissions was	optionally extended to
     40MHz, with full backwards	compatibility to 802.11a/b/g devices which
     cannot decode 40MHz transmissions.	 Several additional features were in-
     troduced, most notably MIMO (multiple-input, multiple-output).  With
     MIMO, a data stream is divided across up to 4 "spatial streams", which
     are transmitted in	parallel by a corresponding amount of antennas.	 Each
     spatial stream is received	with a dedicated antenna, and the spatial
     streams are de-multiplexed	to obtain the original data stream.

     802.11n assigns a numeric identifier to all possible combinations of mod-
     ulation, coding rate, and number of spatial streams.  This	results	in 77
     distinct modulation and coding schemes, abbreviated as "MCS".

     ifmedia supports HT_MCS0 up to HT_MCS31:

	   IFM_IEEE80211_HT_MCSx   HT OFDM MCS x (where	x is in	the range 0 -
				   31, inclusive).  [HT-MCSx]

     In	practice, only MCS-0 to	MCS-32 are supported by	commonly available de-
     vices.  The remaining MCS define combinations where distinct spacial
     streams employ distinct modulations, a feature which was not widely im-
     plemented by hardware vendors.

     The IEEE 802.11ac-2013 standard for "Very High Throughput"	(VHT) wireless
     LAN operates in the 5GHz band only.  The channel bandwidth	for data frame
     transmissions can be up to	160MHz wide.  The MCS identifiers were rede-
     fined and vastly reduced in number.  As a result, only VHT_MCS0 to
     VHT_MCS9 are defined for 802.11ac:

	   IFM_IEEE80211_VHT_MCSx  VHT OFDM MCS	x (where x is in the range 0 -
				   9, inclusive).  [VHT-MCSx]

     The number	of spatial streams is no longer	associated with	a given	VHT
     MCS identifier and	must be	specified as a separate	"NSS" parameter.  This
     parameter is not yet implemented by ifmedia.

MEDIA TYPES AND	OPTIONS	FOR TDM
     The following media types are defined for TDM:

	   IFM_TDM_E1		 E1, 2048kb/s HDB3 encoded, G.703 clearchannel
				 serial	line.  [e1]

	   IFM_TDM_E1_AMI	 E1, 2048kb/s AMI encoded, G.703 clearchannel
				 serial	line.  [e1-ami]

	   IFM_TDM_E1_AMI_G704	 E1, 2048kb/s AMI encoded, G.704 structured
				 serial	line.  [e1-ami-g.704]

	   IFM_TDM_E1_G704	 E1, 2048kb/s HDB3 encoded, G.704 structured
				 serial	line.  [e1-g.704]

	   IFM_TDM_E1_G704_CRC4	 E1, 2048kb/s HDB3 encoded, G.704 structured
				 serial	line with CRC4 checksum.
				 [e1-g.704-crc4]

	   IFM_TDM_E3		 E3, 34368kb/s HDB3 encoded, G.703 clearchan-
				 nel serial line.  [e3]

	   IFM_TDM_E3_G751	 E3, 34368kb/s HDB3 encoded, G.751 structured
				 serial	line.  [e3-g.751]

	   IFM_TDM_E3_G832	 E3, 34368kb/s HDB3 encoded, G.832 structured
				 serial	line.  [e3-g.832]

	   IFM_TDM_T1		 T1, 1536xkb/s B8ZS encoded, extended super
				 frame (ESF) structured	serial line.  [t1]

	   IFM_TDM_T1_AMI	 T1, 1536kb/s AMI encoded, super frame (SF)
				 structured serial line.  [t1-ami]

	   IFM_TDM_T3		 T3, 44736kb/s B3ZS, C-bit structured serial
				 line.	[t3]

	   IFM_TDM_T3_M13	 T3, 44736kb/s B3ZS, M13 structured serial
				 line.	[t3-m13]

     The following media options are defined for TDM:

	   IFM_TDM_HDLC_CRC16  Cisco HDLC with 16-bit CRC checksum encoding.
			       [hdlc-crc16]

	   IFM_TDM_FR_ANSI     ANSI/ITU	Framerelay encoding.  [framerelay-
			       ansi, framerelay-itu]

	   IFM_TDM_FR_CISCO    Cisco Framerelay	encoding.  [framerelay-cisco]

	   IFM_TDM_PPP	       PPP encoding.  [ppp]

     By	default	TDM interfaces will use	Cisco HDLC encoding with a 32-bit CRC
     checksum.

     The following media modes are defined for TDM:

	   IFM_TDM_MASTER  Use local clock source as master clock.  [master]

MEDIA TYPES AND	OPTIONS	FOR CARP
     carp(4) does not support any media	types or options.

SEE ALSO
     netintro(4), ifconfig(8)

HISTORY
     The ifmedia interface first appeared in BSD/OS 3.0.  The implementation
     that appeared in NetBSD 1.3 was written by	Jonathan Stone and Jason R.
     Thorpe to be compatible with the BSDI API.	 It has	since gone through
     several revisions which have extended the API while maintaining backwards
     compatibility with	the original API.

     Support for the IEEE802.11	Wireless LAN link type was added in
     NetBSD 1.5.

     Host AP mode was added in OpenBSD 3.1.

FreeBSD	13.0		       January 21, 2021			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | COMMON MEDIA TYPES AND OPTIONS | MEDIA TYPES AND OPTIONS FOR ETHERNET | MEDIA TYPES AND OPTIONS FOR FDDI | MEDIA TYPES AND OPTIONS FOR IEEE802.11 WIRELESS LAN | MEDIA TYPES AND OPTIONS FOR TDM | MEDIA TYPES AND OPTIONS FOR CARP | SEE ALSO | HISTORY

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