FreeBSD* Driver for Intel Ethernet
===================================
July 7, 2015


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-suppported 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.

NOTE: This release includes two gigabit FreeBSD base Drivers for Intel(R)
      Ethernet. These drivers are em and igb.
 
      - The igb driver supports all 82575 and 82576-based gigabit network
        connections.
      - The em driver supports all other gigabit network connections.


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: Mobile adapters are not fully supported.


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/igb or /usr/local/src/igb.

2. Untar/unzip the archive:

        tar xzvf igb-x.x.x.tar.gz

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

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

	a. To compile the module

	          cd igb-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_igb_load="YES"

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

        ifconfig igbX <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_igb<interface_num>entry:

        ifconfig_igb<interface_num>="<ifconfig_settings>"

   Example usage:

        ifconfig_igb0="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. 
  
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 to auto-negotiate with its link partner since those adapters operate 
only in full duplex and only at their native speed. 

By default, the adapter auto-negotiates the speed and duplex of the 
connection. If there is a specific need, the ifconfig utility can be 
used to configure the speed and duplex settings on the adapter.

Example usage: 

     ifconfig emX <IP_address> media 100baseTX mediaopt full-duplex 
 
NOTE: Only use mediaopt to set the driver to full-duplex. If mediaopt is 
      not specified and you are not running at gigabit speed, the driver 
      defaults to half-duplex. 

If the interface is currently forced to 100 full duplex, you must use this 
command to change to half duplex: 

     ifconfig emX <IP_address> media 100baseTX -mediaopt full-duplex 

This driver supports the following media type options: 

Media Type         Description
----------         -----------
autoselect         Enables auto-negotiation for speed and duplex.

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

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

1000baseTX         Sets speed to 1000 Mbps. In this case, the driver 
                   supports only full-duplex mode. 

1000baseSX         Sets speed to 1000 Mbps. In this case, the driver 
                   supports only full-duplex mode. 

For more information on the ifconfig utility, see the ifconfig man page. 


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

The driver supports Transmit/Receive Checksum Offload and Jumbo Frames.

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 9216. To modify 
the setting, enter the following:

     ifconfig igbX <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 9216. This value coincides
  with the maximum Jumbo Frames size of 9234 bytes.
- Using Jumbo frames at 10 or 100 Mbps is not supported and may result in 
  poor performance or loss of link. 
- The following adapters do not support Jumbo Frames:
    IntelPRO/1000 Gigabit Server Adapter
    Intel PRO/1000 PM Network Connection
    Intel 82562V 10/100 Network Connection
    Intel 82566DM Gigabit Network Connection
    Intel 82566DC Gigabit Network Connection
    Intel 82566MM Gigabit Network Connection
    Intel 82566MC Gigabit Network Connection
    Intel 82562GT 10/100 Network Connection
    Intel 82562G 10/100 Network Connection
    Intel 82566DC-2 Gigabit Network Connection
    Intel 82562V-2 10/100 Network Connection
    Intel 82562G-2 10/100 Network Connection
    Intel 82562GT-2 10/100 Network Connection 
    Intel 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 igb0

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:

     ifconfig <vlan_name> destroy

Polling
-------
NOTES:
- Device Polling is only valid for non-SMP kernels.
- The driver has to be built into the kernel for Device Polling to be 
  enabled in the driver.

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 igbX polling (to turn polling on)
     ifconfig igbX -polling  (to turn it off)

Checksum Offload
----------------
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.

NOTE: Checksum offloading is not supported on 82542-based gigabit adapters.

To enable checksum offloading:

     ifconfig igbX rxcsum 

To disable checksum offloading:

     ifconfig igbX -rxcsum 

To confirm the current setting:

     ifconfig igbX

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 igbX -tso             

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

  -  ifconfig igbX 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. 


LRO
---
Large Receive Offload is available in the driver; it is on by default. 

It can be disabled by using:

     ifconfig <interface_num> -lro

To enable:

     ifconfig <interface_num> lro

EEE
---
Valid Range:  0-1
Default Value: 1 (enabled)

A link between two EEE-compliant devices will result in periodic bursts of 
data followed by long periods where in the link is in an idle state. This Low
Power Idle (LPI) state is supported in both 1Gbps and 100Mbps link speeds.

NOTE: EEE support requires autonegotiation.

DMAC
----
Valid Range: 0, 1, 250, 500, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 
             9000, and 10000
Default Value: 1 (enabled)

Enables or disables DMA Coalescing feature. DMA (Direct Memory Access) allows
the network device to move packet data directly to the system's memory, 
reducing CPU utilitzation. However, the frequency and random intervals at
which packets arrive do not allow the system to enter a lower power state. 
DMA Coalescing allows the adapter to collect packets before it initiates a 
DMA event. This may increase network latency but also increases the chances 
that the system will enter a lower power state. 

InterruptThrottleRate (ITR) should be set to dynamic. This will impart the 
greatest chance for your system to consume less power. DMA Coalescing is 
effective in helping potentially saving the platform power only when it is 
enabled across all active ports.
 
A whitepaper containing information on how to best configure your platform 
is available on the Intel website.

  
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 wont 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:

  cd em-x.x.x
  make clean
  make

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.
