ET(4)							   BSD Kernel Interfaces Manual 						     ET(4)

NAME

     et -- Agere ET1310 10/100/Gigabit Ethernet driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel configuration file:

	   device miibus
	   device et

     Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

	   if_et_load="YES"

DESCRIPTION

     The et driver supports PCI Express Ethernet adapters based on the Agere ET1310 chip.

     The et driver supports the following media types:

     autoselect   Enable autoselection of the media types and options.	The user can manually override the autoselected mode by adding media
		  options to the /etc/rc.conf file.

     10baseT/UTP  Set 10Mbps operation.  The mediaopt option can also be used to select either full-duplex or half-duplex modes.

     100baseTX	  Set 100Mbps (Fast Ethernet) operation.  The mediaopt option can also be used to select either full-duplex or half-duplex modes.

     1000baseT	  Set 1000Mbps (Gigabit Ethernet) operation.  The mediaopt option can only be set to full-duplex mode.

     The et driver supports the following media options:

     full-duplex  Force full-duplex operation.

     half-duplex  Force half-duplex operation.

     Note that the 1000baseT media type is only available if it is supported by the adapter.  For more information on configuring this device, see
     ifconfig(8).

TUNABLES

     hw.et.rx_intr_npkts  This value controls how many packets should be received before a receive interrupt is generated.  The default value is
			  32.  It is recommended to set this value above 38 to prevent the host from being livelocked under a high degree of
			  stress.

     hw.et.rx_intr_delay  This value delays the generation of receive interrupts in units of ~4 microseconds.  It is used together with
			  hw.et.rx_intr_npkts to achieve RX interrupt moderation.  The default value is 20.

     hw.et.tx_intr_nsegs  This value controls how many segments (not packets) should be transmitted before a transmit interrupt is generated.  The
			  default value is 126.  It is recommended to set this value below 280 to prevent the TX ring from underflowing.

     hw.et.timer	  This value controls how often a timer interrupt should be generated.	It is used together with hw.et.tx_intr_nsegs to
			  achieve TX interrupt moderation.  The default value is 1000000000 (nanoseconds).

SEE ALSO

     arp(4), miibus(4), netintro(4), ng_ether(4), vlan(4), ifconfig(8)

HISTORY

     The et device driver first appeared in DragonFly 1.11.  The first FreeBSD release to include it was FreeBSD 8.0.

AUTHORS

     The et driver was written by Sepherosa Ziehau <sepherosa@gmail.com> for DragonFly.  It was ported to FreeBSD by Xin LI <delphij@FreeBSD.org>.

BSD
								   July 14, 2008							       BSD