freebsd-nq/sys/dev/em/README

$FreeBSD$
FreeBSD* Driver for Intel Network Connection
=============================================

May 30, 2007


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 Network Connection.
This driver has been developed for use with FreeBSD, Release 7.x.

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/network/sb/cs-012904.htm


For the latest Intel network drivers for FreeBSD, see:

http://downloadfinder.intel.com/scripts-df-external/support_intel.aspx


NOTE: Mobile adapters are not fully supported.
NOTE: The Intel(R) 82562v 10/100 Network Connection only provides 10/100
support.

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

NOTE: The driver can be installed as a dynamic loadable kernel module or
      compiled into the kernel. You must have kernel sources installed in
      order to compile the driver module.

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.
   NOTE: To compile the driver into the kernel, go directly to step 4.

        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 compile the driver into the kernel, enter:

        cd em-x.x.x/src
        cp *.[ch] /usr/src/sys/dev/em

        Edit the kernel configuration file (i.e., GENERIC or MYKERNEL) in
        /usr/src/sys/i386/conf, and ensure the following line is present:

        device em

        Compile and install the kernel. The system must be rebooted for the
        kernel updates to take effect. For additional information on compiling
        the kernel, consult the FreeBSD operating system documentation.

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

        ifconfig em<interface_num> <IP_address>

6. 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>

7. 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
==============================

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 em<interface_num> <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, in order to change
to half duplex you must use this command:

        ifconfig em<interface_num> <IP_address> media 100baseTX -mediaopt
            full-duplex


This driver supports the following media type options:

   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 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 em<interface_num> <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

  - Adapters based on the Intel(R) 82542 and 82573V/E controller do not
    support Jumbo Frames. These correspond to the following product names:
     Intel(R) PRO/1000 Gigabit Server Adapter
     Intel(R) PRO/1000 PM Network Connection

  - Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or
    loss of link.

  - The following adapters do not support Jumbo Frames:
    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

  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 <interface_num> rxcsum

  To disable checksum offloading:

         ifconfig <interface_num> -rxcsum

  To confirm the current setting:

         ifconfig <interface_num>

  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.


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

  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:
          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:

        http://support.intel.com

If an issue is identified, support is through email only at:
freebsdnic@mailbox.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.