em man page on FreeBSD

Man page or keyword search:  
man Server   9747 pages
apropos Keyword Search (all sections)
Output format
FreeBSD logo
[printable version]

EM(4)			 BSD Kernel Interfaces Manual			 EM(4)

NAME
     emIntel(R) PRO/1000 Gigabit Ethernet adapter driver

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

	   device em

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

	   if_em_load="YES"

DESCRIPTION
     The em driver provides support for PCI Gigabit Ethernet adapters based on
     the Intel 82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546,
     82546EB, 82546GB, 82547, 82571, 81572, 82573, and 82574 Ethernet con‐
     troller chips.  The driver supports Transmit/Receive checksum offload and
     Jumbo Frames on all but 82542-based adapters.  Furthermore it supports
     TCP segmentation offload (TSO) on all adapters but those based on the
     82543, 82544 and 82547 controller chips.  The identification LEDs of the
     adapters supported by the em driver can be controlled via the led(4) API
     for localization purposes.	 For further hardware information, see the
     README included with the driver.

     For questions related to hardware requirements, refer to the documenta‐
     tion supplied with your Intel PRO/1000 adapter.  All hardware require‐
     ments listed apply to use with FreeBSD.

     Support for Jumbo Frames is provided via the interface MTU setting.
     Selecting an MTU larger than 1500 bytes with the ifconfig(8) utility con‐
     figures the adapter to receive and transmit Jumbo Frames.	The maximum
     MTU size for Jumbo Frames is 16114.

     This driver version supports VLANs.  The em driver supports the following
     media types:

     autoselect	  Enables auto-negotiation for speed and duplex.

     10baseT/UTP  Sets 10Mbps operation.  Use the mediaopt option to select
		  full-duplex mode.

     100baseTX	  Sets 100Mbps operation.  Use the mediaopt option to select
		  full-duplex mode.

     1000baseSX	  Sets 1000Mbps operation.  Only full-duplex mode is supported
		  at this speed.

     1000baseTX	  Sets 1000Mbps operation.  Only full-duplex mode is supported
		  at this speed.

     The em driver supports the following media options:

     full-duplex  Forces full-duplex operation

     half-duplex  Forces half-duplex operation.

     Only use mediaopt to set the driver to full-duplex.  If mediaopt is not
     specified, the driver defaults to half-duplex.

     For more information on configuring this device, see ifconfig(8).

HARDWARE
     The em driver supports Gigabit Ethernet adapters based on the Intel
     82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546, 82546EB,
     82546GB, 82547, 82571, 82572, 82573, and 82574 controller chips:

     ·	 Intel PRO/1000 CT Network Connection (82547)
     ·	 Intel PRO/1000 F Server Adapter (82543)
     ·	 Intel PRO/1000 Gigabit Server Adapter (82542)
     ·	 Intel PRO/1000 GT Desktop Adapter (82541PI)
     ·	 Intel PRO/1000 MF Dual Port Server Adapter (82546)
     ·	 Intel PRO/1000 MF Server Adapter (82545)
     ·	 Intel PRO/1000 MF Server Adapter (LX) (82545)
     ·	 Intel PRO/1000 MT Desktop Adapter (82540)
     ·	 Intel PRO/1000 MT Desktop Adapter (82541)
     ·	 Intel PRO/1000 MT Dual Port Server Adapter (82546)
     ·	 Intel PRO/1000 MT Quad Port Server Adapter (82546EB)
     ·	 Intel PRO/1000 MT Server Adapter (82545)
     ·	 Intel PRO/1000 PF Dual Port Server Adapter (82571)
     ·	 Intel PRO/1000 PF Quad Port Server Adapter (82571)
     ·	 Intel PRO/1000 PF Server Adapter (82572)
     ·	 Intel PRO/1000 PT Desktop Adapter (82572)
     ·	 Intel PRO/1000 PT Dual Port Server Adapter (82571)
     ·	 Intel PRO/1000 PT Quad Port Server Adapter (82571)
     ·	 Intel PRO/1000 PT Server Adapter (82572)
     ·	 Intel PRO/1000 T Desktop Adapter (82544)
     ·	 Intel PRO/1000 T Server Adapter (82543)
     ·	 Intel PRO/1000 XF Server Adapter (82544)
     ·	 Intel PRO/1000 XT Server Adapter (82544)

LOADER TUNABLES
     Tunables can be set at the loader(8) prompt before booting the kernel or
     stored in loader.conf(5).

     hw.em.rxd
	     Number of receive descriptors allocated by the driver.  The
	     default value is 256.  The 82542 and 82543-based adapters can
	     handle up to 256 descriptors, while others can have up to 4096.

     hw.em.txd
	     Number of transmit descriptors allocated by the driver.  The
	     default value is 256.  The 82542 and 82543-based adapters can
	     handle up to 256 descriptors, while others can have up to 4096.

     hw.em.rx_int_delay
	     This value delays the generation of receive interrupts in units
	     of 1.024 microseconds.  The default value is 0, since adapters
	     may hang with this feature being enabled.

     hw.em.rx_abs_int_delay
	     If hw.em.rx_int_delay is non-zero, this tunable limits the maxi‐
	     mum delay in which a receive interrupt is generated.

     hw.em.tx_int_delay
	     This value delays the generation of transmit interrupts in units
	     of 1.024 microseconds.  The default value is 64.

     hw.em.tx_abs_int_delay
	     If hw.em.tx_int_delay is non-zero, this tunable limits the maxi‐
	     mum delay in which a transmit interrupt is generated.

DIAGNOSTICS
     em%d: Unable to allocate bus resource: memory  A fatal initialization
     error has occurred.

     em%d: Unable to allocate bus resource: interrupt  A fatal initialization
     error has occurred.

     em%d: watchdog timeout -- resetting  The device has stopped responding to
     the network, or there is a problem with the network connection (cable).

SUPPORT
     For general information and support, go to the Intel support website at:
     http://support.intel.com.

     If an issue is identified with the released source code on the supported
     kernel with a supported adapter, email the specific information related
     to the issue to ⟨freebsdnic@mailbox.intel.com⟩.

FILES
     /dev/led/em*  identification LED device nodes

EXAMPLES
     Make the identification LED of em0 blink:

	   echo f2 > /dev/led/em0

     Turn the identification LED of em0 off again:

	   echo 0 > /dev/led/em0

SEE ALSO
     altq(4), arp(4), igb(4), led(4), netintro(4), ng_ether(4), polling(4),
     vlan(4), ifconfig(8)

HISTORY
     The em device driver first appeared in FreeBSD 4.4.

AUTHORS
     The em driver was written by Intel Corporation
     ⟨freebsdnic@mailbox.intel.com⟩.

BUGS
     Hardware-assisted VLAN processing is disabled by default.	You can enable
     it on an em interface using ifconfig(8).

BSD				 May 14, 2010				   BSD
[top]

List of man pages available for FreeBSD

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
...................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net