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igb Linux* Base Driver for Intel(R) Ethernet Network Connection

July 10, 2024

Contents ^^^^^^^^

Important Notes

Configuring SR-IOV for improved network security

In a virtualized environment, on Intel(R) Ethernet Network Adapters that support SR-IOV, the virtual function (VF) may be subject to malicious behavior. Software-generated layer-two frames, like IEEE 802.3x (link flow control), IEEE 802.1Qbb (priority based flow- control), and others of this type, are not expected and can throttle traffic between the host and the virtual switch, reducing performance.

To resolve this issue, and to ensure isolation from unintended traffic streams, configure all SR-IOV enabled ports for VLAN tagging from the administrative interface on the PF. This configuration allows unexpected, and potentially malicious, frames to be dropped.

Overview

This driver supports Linux* kernel versions 2.6.30 or newer. However, some features may require a newer kernel version. The associated Virtual Function (VF) driver for this driver is igbvf.

Driver information can be obtained using ethtool, lspci, and ip.

This driver is only supported as a loadable module at this time. Intel is not supplying patches against the kernel source to allow for static linking of the drivers.

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

The igb driver supports IEEE 1588 time stamping for kernels 2.6.30 and newer.

Related Documentation

See the "Intel(R) Ethernet Adapters and Devices User Guide" for additional information on features. It is available on the Intel website at https://cdrdv2.intel.com/v1/dl/getContent/705831.

Identifying Your Adapter

For information on how to identify your adapter, and for the latest Intel network drivers, refer to the Intel Support website: https://www.intel.com/support.

Building and Installation

How to Manually Build the Driver

  1. Move the virtual function 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, where "<x.x.x>" is the version number for the driver tar file:

    tar zxf igb-<x.x.x>.tar.gz

  3. Change to the driver src directory, where "<x.x.x>" is the version number for the driver tar:

    cd igb-<x.x.x>/src/

  4. Compile the driver module:

    make install

    The binary will be installed as:

    /lib/modules//updates/drivers/net/ethernet/intel/igb/igb.ko

    The install location listed above is the default location. This may differ for various Linux distributions.

  5. Load the module using the modprobe command.

    To check the version of the driver and then load it:

    modinfo igb modprobe igb

    Alternately, make sure that any older igb drivers are removed from the kernel before loading the new module:

    rmmod igb; modprobe igb

  6. Assign an IP address to the interface by entering the following, where "" is the interface name that was shown in dmesg after modprobe:

    ip address add / dev

  7. 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

Note:

For certain distributions like (but not limited to) Red Hat Enterprise Linux 7 and Ubuntu, once the driver is installed, you may need to update the initrd/initramfs file to prevent the OS loading old versions of the igb driver.For Red Hat distributions:

 dracut --force

For Ubuntu:

 update-initramfs -u

How to Build a Binary RPM Package of This Driver

Note:

RPM functionality has only been tested in Red Hat distributions.

  1. Run the following command, where "<x.x.x>" is the version number for the driver tar file:

    rpmbuild -tb igb-<x.x.x>.tar.gz

    Note:

    For the build to work properly, the currently running kernel MUST match the version and configuration of the installed kernel sources. If you have just recompiled the kernel, reboot the system before building.

  2. After building the RPM, the last few lines of the tool output contain the location of the RPM file that was built. Install the RPM with one of the following commands, where "" is the location of the RPM file:

    rpm -Uvh

    or:

    dnf/yum localinstall

Note:

Building the igb Driver with DCA

If your kernel supports Direct Cache Access (DCA), the driver will build by default with DCA enabled.

Command Line Parameters

If the driver is built as a module, enter optional parameters on the command line with the following syntax:

modprobe igb [

There needs to be a "<VAL#>" for each network port in the system supported by this driver. The values will be applied to each instance, in function order. For example:

modprobe igb InterruptThrottleRate=16000,16000

In this case, there are two network ports supported by igb in the system.

The default value for each parameter is generally the recommended setting unless otherwise noted.

InterruptThrottleRate

Valid Range:

Interrupt Throttle Rate (ITR) controls the number of interrupts each interrupt vector can generate per second. Increasing ITR lowers latency at the cost of increased CPU utilization, though it may help throughput in some circumstances.

Note:

"InterruptThrottleRate" is NOT supported by 82542, 82543, or 82544-based adapters.

LLI (Low Latency Interrupts)

Low Latency Interrupts (LLI) allow for immediate generation of an interrupt upon processing receive packets that match certain criteria as set by the parameters described below.

LLI parameters are not enabled when Legacy interrupts are used. You must be using MSI or MSI-X (see "cat /proc/interrupts") to successfully use LLI.

LLIPort

Valid Range: 0-65535

LLI is configured with the "LLIPort" command-line parameter, which specifies which TCP port should generate Low Latency Interrupts.

For example, using "LLIPort=80" would cause the board to generate an immediate interrupt upon receipt of any packet sent to TCP port 80 on the local machine.

Warning:

Enabling LLI can result in an excessive number of interrupts/second that may cause problems with the system and in some cases may cause a kernel panic.

LLIPush

Valid Range: 0-1

"LLIPush" can be set to be enabled or disabled (default). It is most effective in an environment with many small transactions.

Note:

Enabling "LLIPush" may allow a denial of service attack.

LLISize

Valid Range: 0-1500

"LLISize" causes an immediate interrupt if the board receives a packet smaller than the specified size.

IntMode

Valid Range: 0-2

"IntMode" controls the allowed load time control over the type of interrupt registered for by the driver. MSI-X is required for multiple queue support, and some kernels and combinations of kernel ".config" options will force a lower level of interrupt support.

"cat /proc/interrupts" will show different values for each type of interrupt.

RSS

Valid Range: 0-8

The maximum number of queues allowed are:

This parameter is also affected by the "VMDq" parameter in that it will limit the queues more. For example, if you set an 82575 device to VMDQ Mode 2, you will only be able to set 3 RSS queues. See the following table.

+--------+-------------+ | Model | VMDQ Mode | |========|=============| | Number | 0 1 2 3+ | +--------+-------------+ | 82575 | 4 4 3 1 | +--------+-------------+ | 82576 | 8 2 2 2 | +--------+-------------+ | 82580 | 8 1 1 1 | +--------+-------------+

VMDQ

Valid Range:

Supports enabling VMDq pools as this is needed to support SR-IOV.

This parameter is forced to 1 or more if the "max_vfs" module parameter is used. In addition, the number of queues available for RSS is limited if this is set to 1 or greater.

Note:

When either SR-IOV mode or VMDq mode is enabled, hardware VLAN filtering and VLAN tag stripping/insertion will remain enabled.

max_vfs

This parameter adds support for SR-IOV. It causes the driver to spawn up to "max_vfs" worth of virtual functions.

Valid Range: 0-7

If the value is greater than 0, it will also force the VMDq parameter to be 1 or more.

The parameters for the driver are referenced by position. Thus, if you have a dual port adapter, or more than one adapter in your system, and want "N" virtual functions per port, you must specify a number for each port with each parameter separated by a comma. This example will spawn 4 VFs on the first port:

modprobe igb max_vfs=4

This example will spawn 2 VFs on the first port and 4 VFs on the second port:

modprobe igb max_vfs=2,4

Caution:

Use caution when loading the driver with these parameters. Depending on your system configuration, number of slots, etc., it is impossible to predict in all cases where the positions would be on the command line.

Note:

Neither the device nor the driver control how VFs are mapped into config space. Bus layout will vary by operating system. On operating systems that support it, you can check sysfs to find the mapping.

Note:

When either SR-IOV mode or VMDq mode is enabled, hardware VLAN filtering and VLAN tag stripping/insertion will remain enabled. Please remove the old VLAN filter before the new VLAN filter is added. For example:

 ip link set eth0 vf 0 vlan 100      // set vlan 100 for VF 0
 ip link set eth0 vf 0 vlan 0        // Delete vlan 100
 ip link set eth0 vf 0 vlan 200      // set a new vlan 200 for VF 0

QueuePairs

Valid Range: 0-1

If set to 0, when MSI-X is enabled, the Tx and Rx will attempt to occupy separate vectors.

This option can be overridden to 1 if there are not sufficient interrupts available. This can occur if any combination of RSS, VMDQ, and "max_vfs" results in more than 4 queues being used.

Node

Valid Range: 0-n

The "Node" parameter allows you to choose which NUMA node you want to have the adapter allocate memory from. All driver structures, in- memory queues, and receive buffers will be allocated on the node specified. This parameter is only useful when interrupt affinity is specified; otherwise, part of the interrupt time could run on a different core than where the memory is allocated, causing slower memory access and impacting throughput, CPU, or both.

EEE (Energy Efficient Ethernet)

Valid Range: 0-1

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

Note:

Example:

ethtool --show-eee ethtool --set-eee [eee on|off]

DMAC

Valid Range: 0, 1, 250, 500, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000

This parameter enables or disables the DMA Coalescing (DMAC) feature. Values are in microseconds and set the internal DMA Coalescing internal timer.

DMA (Direct Memory Access) allows the network device to move packet data directly to the system's memory, reducing CPU utilization. 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.

Turning on DMA Coalescing may save energy with kernel 2.6.32 and newer. DMA Coalescing must be enabled across all active ports in order to save platform power.

MDD (Malicious Driver Detection)

Valid Range: 0-1

This parameter is only relevant for I350 devices operating in SR-IOV mode. When this parameter is set, the driver detects malicious VF driver and disables its Tx/Rx queues until a VF driver reset occurs.

Additional Features and Configurations

ethtool

The driver utilizes the ethtool interface for driver configuration and diagnostics, as well as displaying statistical information. The latest ethtool version is required for this functionality. Download it at https://kernel.org/pub/software/network/ethtool/.

Viewing Link Messages

Link messages will not be displayed to the console if the distribution is restricting system messages. In order to see network driver link messages on your console, set dmesg to 8 by entering the following:

dmesg -n 8

Note:

This setting is not saved across reboots.

Configuring the Driver on Different Distributions

Configuring a network driver to load properly when the system is started is distribution dependent. Typically, the configuration process involves adding an alias line to "/etc/modules.conf" or "/etc/modprobe.conf" as well as editing other system startup scripts and/or configuration files. Many popular Linux distributions ship with tools to make these changes for you.

To learn the proper way to configure a network device for your system, refer to your distribution documentation. If during this process you are asked for the driver or module name, the name for the Base Driver is igb.

For example, if you install the igb driver for two adapters (eth0 and eth1) and want to set the interrupt mode to MSI-X and MSI, respectively, add the following to "modules.conf" or "/etc/modprobe.conf":

alias eth0 igb alias eth1 igb options igb IntMode=2,1

Jumbo Frames

Jumbo Frames support is enabled by changing the Maximum Transmission Unit (MTU) to a value larger than the default value of 1500.

Use the ip command to increase the MTU size. For example, enter the following where "" is the interface number:

ip link set mtu 9000 dev ip link set up dev

This setting is not saved across reboots.

Add "MTU=9000" to the following file to make the setting change permanent:

Note:

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) Ethernet 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. 1Gbps speeds and higher cannot be forced. Use the autonegotiation advertising setting to manually set devices for 1 Gbps and higher.

Speed, duplex, and autonegotiation advertising are configured through the ethtool utility.

To see the speed configurations your device supports, run:

ethtool

Caution:

Only experienced network administrators should force speed and duplex or change autonegotiation advertising 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(R) Ethernet 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.

Wake on LAN (WoL) Support

Some adapters do not support Wake on LAN (WoL). To determine if your adapter supports WoL, run the following command:

ethtool

WoL is configured through the ethtool utility. If your Linux distribution does not include ethtool, download and install it from the following website: https://kernel.org/pub/software/network/ethtool/.

For instructions on enabling WoL with ethtool, refer to the website listed above.

WoL will be enabled on the system during the next shutdown or reboot. For this driver version, in order to enable WoL, the igb driver must be loaded prior to shutting down or suspending the system.

Note:

Multiqueue

In this mode, a separate MSI-X vector is allocated for each queue and one for "other" interrupts such as link status change and errors. All interrupts are throttled via interrupt moderation. Interrupt moderation must be used to avoid interrupt storms while the driver is processing one interrupt. The moderation value should be at least as large as the expected time for the driver to process an interrupt. Multiqueue is off by default.

Requirements:

Note:

LRO

Large Receive Offload (LRO) is a technique for increasing inbound throughput of high-bandwidth network connections by reducing CPU overhead. It works by aggregating multiple incoming packets from a single stream into a larger buffer before they are passed higher up the networking stack, thus reducing the number of packets that have to be processed. LRO combines multiple Ethernet frames into a single receive in the stack, thereby potentially decreasing CPU utilization for receives.

Note:

LRO requires 2.4.22 or later kernel version.

"IGB_NO_LRO" is a compile time flag. You can enable it at compile time to add support for LRO from the driver. The flag is used by adding "CFLAGS_EXTRA="-DIGB_NO_LRO"" to the make file when it's being compiled:

make CFLAGS_EXTRA="-DIGB_NO_LRO" install

You can verify that the driver is using LRO by looking at these counters in ethtool:

lro_aggregated: Counts total packets that were combined.

lro_flushed: Counts the number of packets flushed out of LRO.

lro_recycled: Counts the number of buffers returned to the ring from recycling.

Note:

LRO does not support IPv6 and UDP.

IEEE 1588 Precision Time Protocol (PTP) Hardware Clock (PHC)

Precision Time Protocol (PTP) is used to synchronize clocks in a computer network. PTP support varies among Intel devices that support this driver. Use the following command to get a definitive list of PTP capabilities supported by the device:

ethtool -T

Note:

PTP requires 3.0.0 or later kernel version that has PTP support enabled in the kernel and a user-space software daemon.

"IGB_PTP" is a compile time flag. The user can enable it at compile time to add support for PTP from the driver. The flag is used by editing the make file as follows when it is being compiled:

make CFLAGS_EXTRA="-DIGB_PTP" install

Note:

The driver will fail to compile if your kernel does not support PTP.

You can verify that the driver is using PTP by looking at the system log to see whether a PHC was attempted to be registered or not. If you have a kernel and version of ethtool with PTP support, you can check the PTP support in the driver by executing:

ethtool -T

Configuring VLAN Tagging on SR-IOV Enabled Adapter Ports

To configure VLAN tagging for the ports on an SR-IOV enabled adapter, use the following command. The VLAN configuration should be done before the VF driver is loaded or the VM is booted. The VF is not aware of the VLAN tag being inserted on transmit and removed on received frames (sometimes called "port VLAN" mode):

ip link set dev vf vlan

For example, the following will configure PF eth0 and the first VF on VLAN 10:

ip link set dev eth0 vf 0 vlan 10

MAC and VLAN Anti-Spoofing Feature for VFs

When a malicious driver on a Virtual Function (VF) interface attempts to send a spoofed packet, it is dropped by the hardware and not transmitted.

An interrupt is sent to the PF driver notifying it of the spoof attempt. When a spoofed packet is detected, the PF driver will send the following message to the system log (displayed by the dmesg command):

Spoof event(s) detected on VF(n)

where "n" = the VF that attempted to do the spoofing.

Setting MAC Address, VLAN, and Rate Limit Using IProute2 Tool

You can set a MAC address of a Virtual Function (VF), a default VLAN, and the rate limit using the IProute2 tool. Download the latest version of the IProute2 tool from Sourceforge if your version does not have all the features you require.

Known Issues/Troubleshooting

MAC address of Virtual Function changes unexpectedly

If a Virtual Function's MAC address is not assigned in the host, then the VF (virtual function) driver will use a random MAC address. This random MAC address may change each time the VF driver is reloaded. You can assign a static MAC address in the host machine. This static MAC address will survive a VF driver reload.

Software Issues

If your Intel Ethernet Network Connection is not working after installing the driver, verify that you have installed the correct driver.

Intel(R) Active Management Technology 2.0, 2.1, and 2.5 are not supported in conjunction with the Linux driver.

Using the igb driver on 2.4 or older 2.6-based kernels

Due to limited support for PCI-Express in 2.4 kernels and older 2.6 kernels, the igb driver may run into interrupt related problems on some systems, such as no link or hanging when bringing up the device.

We recommend the newer 2.6 based kernels, as these kernels correctly configure the PCI-Express configuration space of the adapter and all intervening bridges. If you are required to use a 2.4 kernel, use a 2.4 kernel newer than 2.4.30. For 2.6 kernels, we recommend using the 2.6.21 kernel or newer.

Alternatively, on 2.6 kernels you may disable MSI support in the kernel by booting with the "pci=nomsi" option or permanently disable MSI support in your kernel by configuring your kernel with "CONFIG_PCI_MSI" unset.

Detected Tx unit hang in quad port adapters

In some cases, ports 3 and 4 don't pass traffic and report "Detected Tx Unit Hang," followed by "NETDEV WATCHDOG: : transmit timed out" errors. Ports 1 and 2 do not show any errors and will pass traffic.

This issue may be resolved by updating to the latest kernel and BIOS. You should use an OS that fully supports Message Signaled Interrupts (MSI) and make sure that MSI is enabled in your system's BIOS.

Compiling the driver

When trying to compile the driver by running make install, the following error may occur:

Linux kernel source not configured - missing version.h

To solve this issue, create the "version.h" file by going to the Linux source tree and entering:

make include/linux/version.h

Performance degradation with Jumbo Frames

Degradation in throughput performance may be observed in some Jumbo frames environments. If this is observed, increasing the application's socket buffer size and/or increasing the "/proc/sys/net/ipv4/tcp_*mem" entry values may help.

See the specific application manual and "/usr/src/linux*/Documentation/networking/ip-sysctl.txt" for more details.

Jumbo Frames on Foundry BigIron 8000 switch

There is a known issue using Jumbo frames when connected to a Foundry BigIron 8000 switch. This is a third-party limitation. If you experience loss of packets, lower the MTU size.

Multiple interfaces on same Ethernet broadcast network

Due to the default ARP behavior on Linux, it is not possible to have one system on two IP networks in the same Ethernet broadcast domain (non-partitioned switch) behave as expected. All Ethernet interfaces will respond to IP traffic for any IP address assigned to the system. This results in unbalanced receive traffic.

If you have multiple interfaces in a server, either turn on ARP filtering by entering the following:

echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter

This only works if your kernel's version is higher than 2.4.5.

Note:

This setting is not saved across reboots. The configuration change can be made permanent by adding the following line to the file "/etc/sysctl.conf":

 net.ipv4.conf.all.arp_filter = 1

Alternatively, you can install the interfaces in separate broadcast domains (either in different switches or in a switch partitioned to VLANs).

Disable Rx Flow Control with ethtool

In order to disable receive flow control using ethtool, you must turn off auto-negotiation on the same command line:

ethtool -A autoneg off rx off

Unplugging network cable while "ethtool -p" is running

In kernel versions 2.5.50 and newer, unplugging the network cable while "ethtool -p" is running will cause the system to become unresponsive to keyboard commands, except for control-alt-delete. Restarting the system should resolve the issue.

Do not use LRO when routing packets

Due to a known general compatibility issue with LRO and routing, do not use LRO when routing packets.

Build error with Asianux 3.0 - Redefinition of typedef "irq_handler_t"

Some systems may experience build issues due to the redefinition of "irq_handler_t". To resolve this issue, build the driver using the command:

make CFLAGS_EXTRA=-DAX_RELEASE_CODE=1 install

Rx page allocation errors

The error, "Page allocation failure. order:0," can occur under stress with kernels 2.6.25 and newer. This is caused by the way the Linux kernel reports this stressed condition.

Unloading Physical Function (PF) Driver Causes System Reboots When VM is Running and VF is Loaded on the VM.

Do not unload the PF driver (igb) while VFs are assigned to guests.

Host may reboot after removing PF when VF is active in guest

Using kernel versions earlier than 3.2, do not unload the PF driver with active VFs. Doing this will cause your VFs to stop working until you reload the PF driver and may cause a spontaneous reboot of your system.

Prior to unloading the PF driver, you must first ensure that all VFs are no longer active. Do this by shutting down all VMs and unloading the VF driver.

Support

For general information, go to the Intel support website at https://www.intel.com/support/

or the Intel Ethernet Linux project hosted by GitHub at https://github.com/intel/ethernet-linux-igb

If an issue is identified with the released source code on a supported kernel with a supported adapter, contact Intel Customer Support at https://www.intel.com/content/www/us/en/support/products/36773 /ethernet-products.html

License

This program is free software; you can redistribute it and/or modify it under the terms and conditions of the GNU General Public License, version 2, as published by the Free Software Foundation.

This program is distributed in the hope it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

The full GNU General Public License is included in this distribution in the file called "COPYING".

Copyright(c) 1999 - 2024, Intel Corporation.

Trademarks

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