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Using the e1000 Base Driver for Gigabit Intel® Network Connections
| Note |
The e1000 driver is no longer maintained as a standalone component. Requests for support should be routed to the maintainer of your Linux distribution. | |
The e1000 driver supports Legacy (PCI, PCI-X*) Gigabit Network Connections.
Overview
The Linux base drivers support the 2.4.x and 2.6.x kernels. These drivers includes support for Itanium® 2 Processor-based systems.
These drivers are only supported as a loadable module. 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 Gigabit adapter. All hardware requirements listed apply to use with Linux.
The following features are now available in supported kernels:
- Native VLANs
- Channel Bonding (teaming)
- SNMP
Channel Bonding documentation can be found in the Linux kernel source: /documentation/networking/bonding.txt.
The driver information previously displayed in the /proc file system is not supported in this release. Alternatively, you can use ethtool (version 1.6 or later), lspci, and ifconfig to obtain the same information. Instructions on updating ethtool can be found in the section Additional configurations later in this document.
| Note |
The Intel® 82562V Fast Ethernet PHY 10/100 Network Connection only provides 10/100 support. | |
Building and installation
To build a binary RPM* package of this driver, run "rpmbuild -tb e1000.tar.gz".
| Notes |
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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 now.
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RPM functionality has only been tested in Red Hat distributions. | |
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Move the base driver tar file to the directory of your choice. For example, use "/home/username/e1000" or "/usr/local/src/e1000".
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Untar/unzip the archive, where <x.x.x> is the version number for the driver tar file:
tar zxf e1000-<x.x.x>.tar.gz
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Change to the driver src directory, where <x.x.x> is the version number for the driver tar:
cd e1000-<x.x.x>/src/
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Compile the driver module:
# make install
The binary will be installed as:
/lib/modules/<KERNEL VERSION>/kernel/drivers/net/e1000/e1000.[k]o
The install location listed above is the default location. This may differ for various Linux distributions.
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Load the module using either the insmod or modprobe command:
modprobe e1000
insmod e1000
Note that for 2.6 kernels the insmod command can be used if the full path to the driver module is specified. For example:
insmod /lib/modules/<KERNEL VERSION>/kernel/drivers/net/e1000/e1000.ko
With 2.6 based kernels also make sure that older e1000 drivers are removed from the kernel, before loading the new module:
rmmod e1000; modprobe e1000
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Assign an IP address to the interface by entering the following, where <x> is the interface number:
ifconfig eth<x> <IP_address>
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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> Command line parameters
If the driver is built as a module, the following optional parameters are used by entering them on the command line with the modprobe command using this syntax:
modprobe e1000 [<option>=<VAL1>,<VAL2>,...]
For example, with two Gigabit PCI adapters, entering:
modprobe e1000 TxDescriptors=80,128
loads the e1000 driver with 80 TX descriptors for the first adapter and 128 TX descriptors for the second adapter.
The default value for each parameter is generally the recommended setting, unless otherwise noted.
| Parameter Name |
Valid Range/Settings |
Default |
Description |
| AutoNeg |
0x01-0x0F, 0x20-0x2F |
0x2F |
This parameter is a bit mask that specifies which speed and duplex settings the board advertises. When this parameter is used, the Speed and Duplex parameters must not be specified.
This parameter is supported only on adapters using copper connections.
| Note |
Refer to the Speed and Duplex section of this readme for more information on the AutoNeg parameter. | | |
| Duplex |
0-2 (0=auto-negotiate, 1=half, 2=full) |
0 |
Defines the direction in which data is allowed to flow. Can be either one or two-directional. If both Duplex and the link partner are set to auto-negotiate, the board auto-detects the correct duplex. If the link partner is forced (either full or half), Duplex defaults to half-duplex.
This parameter is supported only on adapters using copper connections. |
| FlowControl |
0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx) |
Read flow control settings from the EEPROM |
This parameter controls the automatic generation(Tx) and response(Rx) to Ethernet PAUSE frames. |
| InterruptThrottleRate |
(not supported on Intel(R) 82542, 82543 or 82544-based adapters)
Valid Range: 0,1,3,4, 100-100000 (0=off, 1=dynamic, 3=dynamic conservative, 4=simplified balancing)
|
3 |
The driver can limit the amount of interrupts per second that the adapter will generate for incoming packets. It does this by writing a value to the adapter that is based on the maximum amount of interrupts that the adapter will generate per second.
Setting InterruptThrottleRate to a value greater or equal to 100 will program the adapter to send out a maximum of that many interrupts per second, even if more packets have come in. This reduces interrupt load on the system and can lower CPU utilization under heavy load, but will increase latency as packets are not processed as quickly.
The default behaviour of the driver previously assumed a static InterruptThrottleRate value of 8000, providing a good fallback value for all traffic types, but lacking in small packet performance and latency. The hardware can handle many more small packets per second however, and for this reason an adaptive interrupt moderation algorithm was implemented.
Since 7.3.x, the driver has two adaptive modes (setting 1 or 3) in which it dynamically adjusts the InterruptThrottleRate value based on the traffic that it receives. After determining the type of incoming traffic in the last timeframe, it will adjust the InterruptThrottleRate to an appropriate value for that traffic.
The algorithm classifies the incoming traffic every interval into classes. Once the class is determined, the InterruptThrottleRate value is adjusted to suit that traffic type the best. There are three classes defined: "Bulk traffic", for large amounts of packets of normal size; "Low latency", for small amounts of traffic and/or a significant percentage of small packets; and "Lowest latency", for almost completely small packets or minimal traffic.
In dynamic conservative mode, the InterruptThrottleRate value is set to 4000 for traffic that falls in class "Bulk traffic". If traffic falls in the "Low latency" or "Lowest latency" class, the InterruptThrottleRate is increased stepwise to 20000. This default mode is suitable for most applications.
For situations where low latency is vital such as cluster or grid computing, the algorithm can reduce latency even more when InterruptThrottleRate is set to mode 1. In this mode, which operates the same as mode 3, the InterruptThrottleRate will be increased stepwise to 70000 for traffic in class "Lowest latency".
In simplified mode the interrupt rate is based on the ratio of tx and rx traffic. If the bytes per second rate is approximately equal, the interrupt rate will drop as low as 2000 interrupts per second. If the traffic is mostly transmit or mostly receive, the interrupt rate could be as high as 8000.
Setting InterruptThrottleRate to 0 turns off any interrupt moderation and may improve small packet latency, but is generally not suitable for bulk throughput traffic
| Note |
InterruptThrottleRate takes precedence over the TxAbsIntDelay and RxAbsIntDelay parameters. In other words, minimizing the receive and/or transmit absolute delays does not force the controller to generate more interrupts than what the Interrupt Throttle Rate allows. | |
Caution |
If you are using the Intel® PRO/1000 CT Network Connection (controller 82547), setting InterruptThrottleRate to a value greater than 75,000, may hang (stop transmitting) adapters under certain network conditions. If this occurs a NETDEV WATCHDOG message is logged in the system event log. In addition, the controller is automatically reset, restoring the network connection. To eliminate the potential for the hang, ensure that InterruptThrottleRate is set no greater than 75,000 and is not set to 0. | |
| Note |
When e1000 is loaded with default settings and multiple adapters are in use simultaneously, the CPU utilization may increase non-linearly. In order to limit the CPU utilization without impacting the overall throughput, we recommend that you load the driver as follows:
modprobe e1000 InterruptThrottleRate=3000,3000,3000
This sets the InterruptThrottleRate to 3000 interrupts/sec for the first, second, and third instances of the driver. The range of 2000 to 3000 interrupts per second works on a majority of systems and is a good starting point, but the optimal value will be platform-specific. If CPU utilization is not a concern, use RX_POLLING (NAPI) and default driver settings. | | |
| RxDescriptors |
80-4096 |
256 |
This value specifies the number of receive buffer descriptors allocated by the driver. Increasing this value allows the driver to buffer more incoming packets, at the expense of increased system memory utilization.
Each descriptor is 16 bytes. A receive buffer is also allocated for each descriptor and can be either 2048, 4096, 8192, or 16384 bytes, depending on the MTU setting. The maximum MTU size is 16110.
| Note |
MTU designates the frame size. It only needs to be set for Jumbo Frames. Depending on the available system resources, the request for a higher number of receive descriptors may be denied. In this case, use a lower number. | | |
| RxIntDelay |
0-65535 (0=off) |
0 |
This value delays the generation of receive interrupts in units of 1.024 microseconds. Receive interrupt reduction can improve CPU efficiency if properly tuned for specific network traffic. Increasing this value adds extra latency to frame reception and can end up decreasing the throughput of TCP traffic. If the system is reporting dropped receives, this value may be set too high, causing the driver to run out of available receive descriptors.
Caution |
When setting RxIntDelay to a value other than 0, adapters may hang (stop transmitting) under certain network conditions. If this occurs a NETDEV WATCHDOG message is logged in the system event log. In addition, the controller is automatically reset, restoring the network connection. To eliminate the potential for the hang ensure that RxIntDelay is set to zero. | | |
| RxAbsIntDelay |
0-65535 (0=off) |
8 |
This value, in units of 1.024 microseconds, limits the delay in which a receive interrupt is generated. Useful only if RxIntDelay is non-zero, this value ensures that an interrupt is generated after the initial packet is received within the set amount of time. Proper tuning, along with RxIntDelay, may improve traffic throughput in specific network conditions.
This parameter is supported only on 82540, 82545 and later adapters. |
| Speed |
0, 10, 100, 1000 |
0 |
Speed forces the line speed to the specified value in megabits per second (Mbps). If this parameter is not specified or is set to 0 and the link partner is set to auto-negotiate, the board will auto-detect the correct speed. Duplex must also be set when Speed is set to either 10 or 100.
This parameter is supported only on adapters using copper connections. |
| TxDescriptors |
80-4096 |
256 |
This value is the number of transmit descriptors allocated by the driver. Increasing this value allows the driver to queue more transmits. Each descriptor is 16 bytes. |
| TxDescriptorStep |
1 (use every Tx Descriptor)
4 (use every 4th Tx Descriptor) |
1 (use every Tx Descriptor) |
On certain non-Intel architectures, it has been observed that intense TX traffic bursts of short packets may result in an improper descriptor writeback. If this occurs, the driver will report a "TX Timeout" and reset the adapter, after which the transmit flow will restart, though data may have stalled for as much as 10 seconds before it resumes.
The improper writeback does not occur on the first descriptor in a system memory cache-line, which is typically 32 bytes, or 4 descriptors long.
Setting TxDescriptorStep to a value of 4 will ensure that all TX descriptors are aligned to the start of a system memory cache line, and so this problem will not occur.
| Notes |
Setting TxDescriptorStep to 4 effectively reduces the number of TxDescriptors available for transmits to 1/4 of the normal allocation. This has a possible negative performance impact, which may be compensated for by allocating more descriptors using the TxDescriptors module parameter.
There are other conditions which may result in "TX Timeout", which will not be resolved by the use of the TxDescriptorStep parameter. As the issue addressed by this parameter has never been observed on Intel Architecture platforms, it should not be used on Intel platforms. | | |
| TxIntDelay |
0-65535 (0=off) |
8 |
This value delays the generation of transmit interrupts in units of 1.024 microseconds. Transmit interrupt reduction can improve CPU efficiency if properly tuned for specific network traffic. If the system is reporting dropped transmits, this value may be set too high causing the driver to run out of available transmit descriptors. |
| TxAbsIntDelay |
0-65535 (0=off) |
32 |
This value, in units of 1.024 microseconds, limits the delay in which a transmit interrupt is generated. Useful only if TxIntDelay is non-zero, this value ensures that an interrupt is generated after the initial packet is sent on the wire within the set amount of time. Proper tuning, along with TxIntDelay, may improve traffic throughput in specific network conditions.
This parameter is supported only on 82540, 82545 and later adapters. |
| XsumRX |
0-1 |
1 |
A value of "1" indicates that the driver should enable IP checksum offload for received packets (both UDP and TCP) to the adapter hardware.
This parameter is not supported on the 82542-based adapter. |
| Copybreak |
0-xxxxxxx (0=off) |
256 |
Usage: insmod e1000.ko copybreak=128
Driver copies all packets below or equaling this size to a fresh rx buffer before handing it up the stack.
This parameter is different than other parameters, in that it is a single (not 1,1,1 etc.) parameter applied to all driver instances and it is also available during runtime at /sys/module/e1000/parameters/copybreak. |
| SmartPowerDownEnable |
0-1
|
0 (disabled) |
Allows Phy to turn off in lower power states. The user can turn off this parameter in supported chipsets. |
| KumeranLockLoss |
0-1 |
1 (enabled) |
This workaround skips resetting the Phy at shutdown for the initial silicon releases of ICH8 systems. |
| TxDescPower |
6-12 |
12 |
This value represents the size-order of each transmit descriptor. The valid size for descriptors would be 2^6 (64) to 2^12 (4096) bytes each. As this value decreases one may want to consider increasing the TxDescriptors value to maintain the same amount of frame memory. | |
Speed and duplex configuration
Three keywords are used to control the speed and duplex configuration. These keywords are Speed, Duplex, and AutoNeg.
If the board uses a fiber interface, these keywords are ignored, and the fiber interface board only links at 1000 Mbps full-duplex.
For copper-based boards, the keywords interact as follows:
- The default operation is auto-negotiate. The board advertises all supported speed and duplex combinations, and it links at the highest common speed and duplex mode IF the link partner is set to auto-negotiate.
- If Speed = 1000, limited auto-negotiation is enabled and only 1000 Mbps is advertised (The 1000BaseT spec requires auto-negotiation.)
- If Speed = 10 or 100, then both Speed and Duplex should be set. Auto-negotiation is disabled, and the AutoNeg parameter is ignored. Partner SHOULD also be forced.
The AutoNeg parameter is used when more control is required over the auto-negotiation process. It should be used when you wish to control which speed and duplex combinations are advertised during the auto-negotiation process. The parameter may be specified as either a decimal or hexadecimal value as determined by the bitmap below.
| Bit Position |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Decimal Value |
128 |
64 |
32 |
16 |
8 |
4 |
2 |
1 |
| Hex Value |
80 |
40 |
20 |
10 |
8 |
4 |
2 |
1 |
| Speed (Mbps): |
N/A |
N/A |
1000 |
N/A |
100 |
100 |
10 |
10 |
| Duplex: |
|
|
Full |
|
Full |
Half |
Full |
Half | |
Some examples of using AutoNeg:
- modprobe e1000 AutoNeg=0x01 (Restricts autonegotiation to 10 Half)
- modprobe e1000 AutoNeg=1 (Same as above)
- modprobe e1000 AutoNeg=0x02 (Restricts autonegotiation to 10 Full)
- modprobe e1000 AutoNeg=0x03 (Restricts autonegotiation to 10 Half or 10 Full)
- modprobe e1000 AutoNeg=0x04 (Restricts autonegotiation to 100 Half)
- modprobe e1000 AutoNeg=0x05 (Restricts autonegotiation to 10 Half or 100 Half)
- modprobe e1000 AutoNeg=0x020 (Restricts autonegotiation to 1000 Full)
- modprobe e1000 AutoNeg=32 (Same as above)
| Note |
When this parameter is used, Speed and Duplex must not be specified. | |
If the link partner is forced to a specific speed and duplex, then this parameter should not be used. Instead, use the Speed and Duplex parameters previously mentioned to force the adapter to the same speed and duplex.
Additional configurations
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 Linux Base Driver for the Gigabit family of adapters is e1000.
As an example, if you install the e1000 driver for two Gigabit adapters (eth0 and eth1) and set the speed and duplex to 10full and 100half, add the following to modules.conf or /etc/modprobe.conf:
alias eth0 e1000
alias eth1 e1000
options e1000 Speed=10,100 Duplex=2,1
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 eight by entering the following:
dmesg -n 8
| Note |
This setting is not saved across reboots. | |
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 ifconfig command to increase the MTU size. For example:
ifconfig eth<x> mtu 9000 up
This setting is not saved across reboots. The setting change can be made permanent by adding MTU=9000 to the file: /etc/sysconfig/network-scripts/ifcfg-eth<x> (Red Hat distributions). Other distributions may store this setting in a different location.
| Note |
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To enable jumbo frames, increase the MTU size on the interface beyond 1500.
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The maximum MTU setting for jumbo frames is 16110. This value coincides with the maximum Jumbo Frames size of 16128.
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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® 82571EB, 82572EI, 82573L, 82566, 82562, 82575, and 80003ES2LAN controllers. These correspond to the following product names:
Intel® PRO/1000 PT Server Adapter
Intel® PRO/1000 PT Desktop Adapter
Intel® PRO/1000 PT Network Connection
Intel® PRO/1000 PT Dual Port Server Adapter
Intel® PRO/1000 PT Dual Port Network Connection
Intel® PRO/1000 PF Server Adapter
Intel® PRO/1000 PF Network Connection
Intel® PRO/1000 PF Dual Port Server Adapter
Intel® PRO/1000 PB Server Connection
Intel® PRO/1000 PL Network Connection
Intel® PRO/1000 EB Network Connection with I/O Acceleration
Intel® PRO/1000 EB Backplane Connection with I/O Acceleration
Intel® PRO/1000 PT Quad Port Server Adapter
Intel® PRO/1000 PF Quad Port Server Adapter
Intel® 82566DM-2 Gigabit Network Connection
Intel® Gigabit PT Quad Port Server ExpressModule
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Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or loss of link
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The following adapters do not support jumbo frames:
Intel® PRO/1000 Gigabit Server Adapter
Intel® PRO/1000 PM Network Connection
Intel® 82562V Fast Ethernet PHY 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 Fast Ethernet PHY-2 10/100 Network Connection
Intel® 82562G-2 10/100 Network Connection
Intel® 82562GT-2 10/100 Network Connection | |
Ethtool
The driver utilizes the ethtool interface for driver configuration and diagnostics, as well as displaying statistical information. Ethtool version 3 or later is required for this functionality, although we strongly recommend downloading the latest version at:
Sourceforge Enabling Wake on LAN* (WoL)
WoL is 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 Web site:
Sourceforge
For instructions on enabling WoL with Ethtool, refer to the Web site listed above.
WoL will be enabled on the system during the next shut down or reboot. For this driver version, in order to enable WoL, the e1000 driver must be loaded prior to shutting down or suspending the system.
| Notes |
Wake On LAN is only supported on port A for the following devices:
- Intel® PRO/1000 PT Dual Port Network Connection
- Intel® PRO/1000 PT Dual Port Server Connection
- Intel® PRO/1000 PT Dual Port Server Adapter
- Intel® PRO/1000 PF Dual Port Server Adapter
- Intel® PRO/1000 PT Quad Port Server Adapter
- Intel® Gigabit PT Quad Port Server ExpressModule
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NAPI
NAPI (Rx polling mode) is supported in the e1000 driver. NAPI is enabled or disabled based on the configuration of the kernel. To override the default, use the following compile-time flags.
To enable NAPI, compile the driver module, passing in a configuration option:
dmesg # make CFLAGS_EXTRA=-DE1000_NAPI install
To disable NAPI, compile the driver module, passing in a configuration option:
dmesg # make CFLAGS_EXTRA=-DE1000_NO_NAPI install
Operating System:
This applies to:
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