FreeBSD* Driver for Intel® Ethernet
===================================

July 30, 2013


Contents
========

- Overview
- Identifying Your Adapter
- Building and Installation
- Speed and Duplex Configuration
- Additional Configurations
- Known Limitations
- Support
- License


Overview
========

This file describes the FreeBSD* driver for Intel® Ethernet. This driver has 
been developed for use with all community-supported versions of FreeBSD.

For questions related to hardware requirements, refer to the documentation 
supplied with your Gigabit adapter. All hardware requirements listed 
apply to use with FreeBSD.


Identifying Your Adapter
========================

For information on how to identify your adapter, go to the Adapter & 
Driver ID Guide at: 

http://support.intel.com/support/go/network/adapter/proidguide.htm


For the latest Intel network drivers for FreeBSD, see: 

http://downloadcenter.intel.com

NOTE: The Intel(R) 82562v 10/100 Network Connection only provides 10/100
support.

Building and Installation
=========================

NOTE: This driver package is to be used only as a standalone archive and the
user should not attempt to incorporate it into the kernel source tree.


In the instructions below, x.x.x is the driver version as indicated in the 
name of the driver tar file.

1. Move the base driver tar file to the directory of your choice. For 
   example, use /home/username/em or /usr/local/src/em.

2. Untar/unzip the archive:

        tar xzvf em-x.x.x.tar.gz

   This will create an em-x.x.x directory.

3. To create a loadable module, perform the following steps. 

	a. To compile the module

	          cd em-x.x.x
      	          make

   	b. To install the compiled module to the system directory:
	 
		  make install
		
   	c. If you want the driver to load automatically when the system is booted:

	      1. Edit /boot/loader.conf, and add the following line:

      	          if_em_load="YES"

4. To assign an IP address to the interface, enter the following:

        ifconfig emX <IP_address>

5. Verify that the interface works. Enter the following, where <IP_address>
   is the IP address for another machine on the same subnet as the interface
   that is being tested:

        ping <IP_address>

6. To configure the IP address to remain after reboot, edit /etc/rc.conf, 
   and create the appropriate ifconfig_em<interface_num> entry:

        ifconfig_em<interface_num>="<ifconfig_settings>"

   Example usage:

        ifconfig_em0="inet 192.168.10.1 netmask 255.255.255.0"

   NOTE: For assistance, see the ifconfig man page.


Speed and Duplex Configuration
==============================
  In addressing speed and duplex configuration issues, you need to 
  distinguish between copper-based adapters and fiber-based adapters. 


  In the default mode, an Intel(R) Network Adapter using copper connections 
  will attempt to auto-negotiate with its link partner to
  determine the best setting. If the adapter cannot establish link with the 
  link partner using auto-negotiation, you may need to manually configure the 
  adapter and link partner to identical settings to establish link and pass
  packets. This should only be needed when attempting to link with an older 
  switch that does not support auto-negotiation or one that has been forced 
  to a specific speed or duplex mode. Your link partner must match the 
  setting you choose. 
  
  Speed and Duplex are configured through the ethtool* utility. ethtool is 
  included with all versions of Red Hat after Red Hat 7.2. For other Linux
  distributions, download and install ethtool from the following website: 
  <a href="http://ftp.kernel.org/pub/software/network/ethtool/.

  Caution: Only experienced network administrators should force speed and 
  duplex manually. The settings at the switch must always match the adapter 
  settings. Adapter performance may suffer or your adapter may not 
  operate if you configure the adapter differently from your switch.

  An Intel® Network Adapter using fiber-based connections, however, will not 
  attempt auto-negotiate with its link partner since those adapters operate 
  only in full duplex, and only at their native speed. 


Additional Configurations
=========================

The driver supports Transmit/Receive Checksum Offload and Jumbo Frames on 
all but the 82542-based adapters.  For specific adapters, refer to the 
Identifying Your Adapter section.

  Jumbo Frames
  ------------
  To enable Jumbo Frames, use the ifconfig utility to set the Maximum 
  Transport Unit (MTU) frame size above its default of 1500 bytes. 

  The Jumbo Frames MTU range for Intel Adapters is 1500 to 16110. To modify 
  the setting, enter the following:

        ifconfig emX <hostname or IP address> mtu 9000

  To confirm the MTU used between two specific devices, use:

        route get <destination_IP_address>

  Notes: 

  - Only enable Jumbo Frames if your network infrastructure supports them.

  - To enable Jumbo Frames, increase the MTU size on the interface beyond 
    1500.

  - The Jumbo Frames setting on the switch must be set to at least 22 bytes 
    larger than that of the MTU.

  - The maximum MTU setting for Jumbo Frames is 16110.  This value coincides 
    with the maximum Jumbo Frames size of 16128.

  - Some Intel gigabit adapters that support Jumbo Frames have a frame size 
    limit of 9238 bytes, with a corresponding MTU size limit of 9216 bytes.  
    The adapters with this limitation are based on the Intel(R) 82571EB, 
    82572EI, 82573L, 82566, 82562, and 80003ES2LAN controller.  These 
    correspond to the following product names:
     Intel(R) PRO/1000 PT Server Adapter
     Intel(R) PRO/1000 PT Desktop Adapter
     Intel(R) PRO/1000 PT Network Connection
     Intel(R) PRO/1000 PT Dual Port Server Adapter
     Intel(R) PRO/1000 PT Dual Port Network Connection
     Intel(R) PRO/1000 PT Quad Port Server Adapter
     Intel(R) PRO/1000 PF Quad Port Server Adapter
     Intel(R) PRO/1000 PF Server Adapter
     Intel(R) PRO/1000 PF Network Connection
     Intel(R) PRO/1000 PF Dual Port Server Adapter
     Intel(R) PRO/1000 PB Server Connection
     Intel(R) PRO/1000 PL Network Connection
     Intel(R) PRO/1000 EB Network Connection with I/O Acceleration
     Intel(R) PRO/1000 EB Backplane Connection with I/O Acceleration
     Intel(R) 82566DM-2 Gigabit Network Connection
     Intel(R) 82574L Gigabit Network Connection
     Intel(R) Gigabit CT Desktop Adapter
     Intel(R) 82567LM-4 Gigabit Network Connection
     Intel(R) 82567LM-3 Gigabit Network Connection
     Intel(R) 82567LF-3 Gigabit Network Connection

  - Using Jumbo frames at 10 or 100 Mbps is not supported and may result in 
    poor performance or loss of link. 

  - The following adapters limit Jumbo Frames sized packets to a maximum of
    4088 bytes:
    Intel(R) 82578DM Gigabit Network Connection 

  - The following adapters do not support Jumbo Frames:
    Intel(R) PRO/1000 Gigabit Server Adapter
    Intel(R) PRO/1000 PM Network Connection
    Intel(R) 82562V 10/100 Network Connection
    Intel(R) 82566DM Gigabit Network Connection
    Intel(R) 82566DC Gigabit Network Connection
    Intel(R) 82566MM Gigabit Network Connection
    Intel(R) 82566MC Gigabit Network Connection
    Intel(R) 82562GT 10/100 Network Connection
    Intel(R) 82562G 10/100 Network Connection
    Intel(R) 82566DC-2 Gigabit Network Connection
    Intel(R) 82562V-2 10/100 Network Connection
    Intel(R) 82562G-2 10/100 Network Connection
    Intel(R) 82562GT-2 10/100 Network Connection 
    Intel(R) 82578DC Gigabit Network Connection 
    Intel(R) 82567V-3 Gigabit Network Connection

  VLANs
  -----
  To create a new VLAN interface:

        ifconfig <vlan_name> create

  To associate the VLAN interface with a physical interface and 
  assign a VLAN ID, IP address, and netmask:

        ifconfig <vlan_name> <ip_address> netmask <subnet_mask> vlan 
           <vlan_id> vlandev <physical_interface>

  Example:

        ifconfig vlan10 10.0.0.1 netmask 255.255.255.0 vlan 10 vlandev em0

  In this example, all packets will be marked on egress with 802.1Q VLAN 
  tags, specifying a VLAN ID of 10.

  To remove a VLAN interface:

  Intel® Network Connection        ifconfig <vlan_name> destroy


  Polling
  -------
  
  To enable polling in the driver, add the following options to the kernel 
  configuration, and then recompile the kernel:

        options DEVICE_POLLING
        options HZ=1000

  At runtime use: 
        ifconfig emX polling (to turn polling on)
  and:   
	ifconfig emX -polling  (to turn it off)


  Checksum Offload
  ----------------
  Checksum offloading is not supported on 82542 Gigabit adapters. 

  Checksum offloading supports both TCP and UDP packets and is supported 
  for both transmit and receive. 

  Checksum offloading can be enabled or disabled using ifconfig. Both transmit
  and receive offloading will be either enabled or disabled together. You
  cannot enable/disable one without the other.

  To enable checksum offloading:

         ifconfig emX rxcsum 

  To disable checksum offloading:

         ifconfig emX -rxcsum 

  To confirm the current setting:

         ifconfig emX

  Look for the presence or absence of the following line:

         options=3 <RXCSUM,TXCSUM>

  See the ifconfig man page for further information. 


  TSO
  ---
  The FreeBSD driver offers support for TSO (TCP Segmentation Offload).

  You can enable/disable it in two ways/places:

        -  sysctl net.inet.tcp.tso=0	(or 1 to enable it)

  Doing this disables TSO in the stack and will affect all adapters.

        -  ifconfig emX -tso             

  Doing this will disable TSO only for this adapter.
 
  To enable:

        -  ifconfig emX tso 

  NOTES: By default only PCI-Express adapters are ENABLED to do TSO. Others 
  can be enabled by the user at their own risk
  TSO is not supported on 82547 and 82544-based adapters, as well as older 
  adapters.

  MSI-X
  -----
  The FreeBSD driver offers MSIX support with 82574L-based network connections.
  82574L-based network connections will use MSI-X by default. 

  MSI or MSI-X can be turned off by an entry in /etc/sysctl.conf

          hw.em.enable_msi=0

  Unload and reload the driver.

  
Known Limitations
=================

For known hardware and troubleshooting issues, refer to the following website.

    http://support.intel.com/support/go/network/adapter/home.htm

Either select the link for your adapter or perform a search for the adapter 
number. The adapter's page lists many issues. For a complete list of hardware
issues download your adapter's user guide and read the Release Notes. 
 
  Detected Tx Unit Hang in Quad Port Adapters
  -------------------------------------------

  In some cases ports 3 and 4 won’t pass traffic. Ports 1 and 2 don't show 
  any errors and will pass traffic.

  This issue MAY be resolved by updating to the latest BIOS. You can 
  check your system's BIOS by downloading the Linux Firmware Developer Kit 
  that can be obtained at http://www.linuxfirmwarekit.org/


  There are known performance issues with this driver when running UDP traffic
  with Jumbo Frames. 
  ----------------------------------------------------------------------------

  82541/82547 can't link or is slow to link with some link partners
  -----------------------------------------------------------------
  
  There is a known compatibility issue where time to link is slow or link is not 
  established between 82541/82547 controllers and some switches.  Known switches
  include:
        Planex FXG-08TE
        I-O Data ETG-SH8

  The driver can be compiled with the following changes:

  Edit ./em.x.x.x/src/if_em.h to change the #define EM_MASTER_SLAVE 
  For example, change from:

      #define EM_MASTER_SLAVE   e1000_ms_hw_default
  to:
      #define EM_MASTER_SLAVE   2 

  Use one of the following options:
      1 = Master mode
      2 = Slave mode
      3 = Auto master/slave
  Setting 2 is recommended.

  Recompile the module:
	  a. To compile the module
		cd em-x.x.x
          	make clean
          	make

   b. To install the compiled module in system directory:
 		make install


Support
=======

For general information and support, go to the Intel support website at:

        www.intel.com/support/

If an issue is identified, support is through email only at:
freebsd@intel.com


License
=======

This software program is released under the terms of a license agreement 
between you ('Licensee') and Intel. Do not use or load this software or any 
associated materials (collectively, the 'Software') until you have carefully 
read the full terms and conditions of the LICENSE located in this software 
package. By loading or using the Software, you agree to the terms of this 
Agreement. If you do not agree with the terms of this Agreement, do not 
install or use the Software.

* Other names and brands may be claimed as the property of others.