The default value for each parameter is generally the recommended setting,
unless otherwise noted.
-NOTES: For more information about the AutoNeg, Duplex, and Speed
+NOTES:
+ For more information about the AutoNeg, Duplex, and Speed
parameters, see the "Speed and Duplex Configuration" section in
this document.
AutoNeg
-------
+
(Supported only on adapters with copper connections)
-Valid Range: 0x01-0x0F, 0x20-0x2F
-Default Value: 0x2F
+
+:Valid Range: 0x01-0x0F, 0x20-0x2F
+:Default Value: 0x2F
This parameter is a bit-mask that specifies the speed and duplex settings
advertised by the adapter. When this parameter is used, the Speed and
Duplex parameters must not be specified.
-NOTE: Refer to the Speed and Duplex section of this readme for more
+NOTE:
+ Refer to the Speed and Duplex section of this readme for more
information on the AutoNeg parameter.
Duplex
------
+
(Supported only on adapters with copper connections)
-Valid Range: 0-2 (0=auto-negotiate, 1=half, 2=full)
-Default Value: 0
+
+:Valid Range: 0-2 (0=auto-negotiate, 1=half, 2=full)
+:Default Value: 0
This 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
FlowControl
-----------
-Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)
-Default Value: Reads flow control settings from the EEPROM
+
+:Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)
+:Default Value: Reads 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)
-Default Value: 3
+
+:Valid Range:
+ 0,1,3,4,100-100000 (0=off, 1=dynamic, 3=dynamic conservative,
+ 4=simplified balancing)
+:Default Value: 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
and may improve small packet latency, but is generally not suitable
for bulk throughput traffic.
-NOTE: InterruptThrottleRate takes precedence over the TxAbsIntDelay and
+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(R) PRO/1000 CT Network Connection
+CAUTION:
+ If you are using the Intel(R) 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
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
+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
RxDescriptors
-------------
-Valid Range: 48-256 for 82542 and 82543-based adapters
- 48-4096 for all other supported adapters
-Default Value: 256
+
+:Valid Range:
+ - 48-256 for 82542 and 82543-based adapters
+ - 48-4096 for all other supported adapters
+:Default Value: 256
This value specifies the number of receive buffer descriptors allocated
by the driver. Increasing this value allows the driver to buffer more
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
+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
----------
-Valid Range: 0-65535 (0=off)
-Default Value: 0
+
+:Valid Range: 0-65535 (0=off)
+:Default Value: 0
This value delays the generation of receive interrupts in units of 1.024
microseconds. Receive interrupt reduction can improve CPU efficiency if
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
+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,
RxAbsIntDelay
-------------
+
(This parameter is supported only on 82540, 82545 and later adapters.)
-Valid Range: 0-65535 (0=off)
-Default Value: 128
+
+:Valid Range: 0-65535 (0=off)
+:Default Value: 128
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,
Speed
-----
+
(This parameter is supported only on adapters with copper connections.)
-Valid Settings: 0, 10, 100, 1000
-Default Value: 0 (auto-negotiate at all supported speeds)
+
+:Valid Settings: 0, 10, 100, 1000
+:Default Value: 0 (auto-negotiate at all supported speeds)
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
TxDescriptors
-------------
-Valid Range: 48-256 for 82542 and 82543-based adapters
- 48-4096 for all other supported adapters
-Default Value: 256
+
+:Valid Range:
+ - 48-256 for 82542 and 82543-based adapters
+ - 48-4096 for all other supported adapters
+:Default Value: 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.
-NOTE: Depending on the available system resources, the request for a
+NOTE:
+ Depending on the available system resources, the request for a
higher number of transmit descriptors may be denied. In this case,
use a lower number.
TxIntDelay
----------
-Valid Range: 0-65535 (0=off)
-Default Value: 8
+
+:Valid Range: 0-65535 (0=off)
+:Default Value: 8
This value delays the generation of transmit interrupts in units of
1.024 microseconds. Transmit interrupt reduction can improve CPU
TxAbsIntDelay
-------------
+
(This parameter is supported only on 82540, 82545 and later adapters.)
-Valid Range: 0-65535 (0=off)
-Default Value: 32
+
+:Valid Range: 0-65535 (0=off)
+:Default Value: 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,
XsumRX
------
+
(This parameter is NOT supported on the 82542-based adapter.)
-Valid Range: 0-1
-Default Value: 1
+
+:Valid Range: 0-1
+:Default Value: 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.
Copybreak
---------
-Valid Range: 0-xxxxxxx (0=off)
-Default Value: 256
-Usage: modprobe e1000.ko copybreak=128
+
+:Valid Range: 0-xxxxxxx (0=off)
+:Default Value: 256
+:Usage: modprobe e1000.ko copybreak=128
Driver copies all packets below or equaling this size to a fresh RX
buffer before handing it up the stack.
SmartPowerDownEnable
--------------------
-Valid Range: 0-1
-Default Value: 0 (disabled)
+
+:Valid Range: 0-1
+:Default Value: 0 (disabled)
Allows PHY to turn off in lower power states. The user can turn off
this parameter in supported chipsets.
For copper-based boards, the keywords interact as follows:
- The default operation is auto-negotiate. The board advertises all
+- 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
+- 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-
+- 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 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:
+Some examples of using AutoNeg::
modprobe e1000 AutoNeg=0x01 (Restricts autonegotiation to 10 Half)
modprobe e1000 AutoNeg=1 (Same as above)
Jumbo Frames
------------
-Jumbo Frames support is enabled by changing the MTU to a value larger
-than the default of 1500. Use the ifconfig command to increase the MTU
-size. For example::
+
+ Jumbo Frames support is enabled by changing the MTU to a value larger than
+ the default 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. It can be made permanent if
-you add::
+ This setting is not saved across reboots. It can be made permanent if
+ you add::
MTU=9000
-to the file /etc/sysconfig/network-scripts/ifcfg-eth<x>. This example
-applies to the Red Hat distributions; other distributions may store this
-setting in a different location.
+ to the file /etc/sysconfig/network-scripts/ifcfg-eth<x>. This example
+ applies to the Red Hat distributions; other distributions may store this
+ setting in a different location.
+
+Notes:
+ 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.
-Notes: 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.
+ - The maximum MTU setting for Jumbo Frames is 16110. This value coincides
+ with the maximum Jumbo Frames size of 16128.
-- The maximum MTU setting for Jumbo Frames is 16110. This value
- coincides with the maximum Jumbo Frames size of 16128.
+ - Using Jumbo frames at 10 or 100 Mbps is not supported and may result in
+ poor performance or loss of link.
-- Using Jumbo frames at 10 or 100 Mbps is not supported and may result
- in poor performance or loss of link.
+ - Adapters based on the Intel(R) 82542 and 82573V/E controller do not
+ support Jumbo Frames. These correspond to the following product names::
-- 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
+ Intel(R) PRO/1000 Gigabit Server Adapter
+ Intel(R) PRO/1000 PM Network Connection
ethtool
-------
-The driver utilizes the ethtool interface for driver configuration and
-diagnostics, as well as displaying statistical information. The ethtool
-version 1.6 or later is required for this functionality.
-The latest release of ethtool can be found from
-https://www.kernel.org/pub/software/network/ethtool/
+ The driver utilizes the ethtool interface for driver configuration and
+ diagnostics, as well as displaying statistical information. The ethtool
+ version 1.6 or later is required for this functionality.
+
+ The latest release of ethtool can be found from
+ https://www.kernel.org/pub/software/network/ethtool/
Enabling Wake on LAN* (WoL)
---------------------------
-WoL is configured through the ethtool* utility.
-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 when shutting down or rebooting the system.
+ WoL is configured through the ethtool* utility.
+ 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 when shutting down or rebooting the system.
Support
=======