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@@ -1,82 +1,35 @@
1Linux* Base Driver for the Intel(R) PRO/1000 Family of Adapters 1Linux* Base Driver for the Intel(R) PRO/1000 Family of Adapters
2=============================================================== 2===============================================================
3 3
4September 26, 2006 4Intel Gigabit Linux driver.
5 5Copyright(c) 1999 - 2010 Intel Corporation.
6 6
7Contents 7Contents
8======== 8========
9 9
10- In This Release
11- Identifying Your Adapter 10- Identifying Your Adapter
12- Building and Installation
13- Command Line Parameters 11- Command Line Parameters
14- Speed and Duplex Configuration 12- Speed and Duplex Configuration
15- Additional Configurations 13- Additional Configurations
16- Known Issues
17- Support 14- Support
18 15
19
20In This Release
21===============
22
23This file describes the Linux* Base Driver for the Intel(R) PRO/1000 Family
24of Adapters. This driver includes support for Itanium(R)2-based systems.
25
26For questions related to hardware requirements, refer to the documentation
27supplied with your Intel PRO/1000 adapter. All hardware requirements listed
28apply to use with Linux.
29
30The following features are now available in supported kernels:
31 - Native VLANs
32 - Channel Bonding (teaming)
33 - SNMP
34
35Channel Bonding documentation can be found in the Linux kernel source:
36/Documentation/networking/bonding.txt
37
38The driver information previously displayed in the /proc filesystem is not
39supported in this release. Alternatively, you can use ethtool (version 1.6
40or later), lspci, and ifconfig to obtain the same information.
41
42Instructions on updating ethtool can be found in the section "Additional
43Configurations" later in this document.
44
45NOTE: The Intel(R) 82562v 10/100 Network Connection only provides 10/100
46support.
47
48
49Identifying Your Adapter 16Identifying Your Adapter
50======================== 17========================
51 18
52For more information on how to identify your adapter, go to the Adapter & 19For more information on how to identify your adapter, go to the Adapter &
53Driver ID Guide at: 20Driver ID Guide at:
54 21
55 http://support.intel.com/support/network/adapter/pro100/21397.htm 22 http://support.intel.com/support/go/network/adapter/idguide.htm
56 23
57For the latest Intel network drivers for Linux, refer to the following 24For the latest Intel network drivers for Linux, refer to the following
58website. In the search field, enter your adapter name or type, or use the 25website. In the search field, enter your adapter name or type, or use the
59networking link on the left to search for your adapter: 26networking link on the left to search for your adapter:
60 27
61 http://downloadfinder.intel.com/scripts-df/support_intel.asp 28 http://support.intel.com/support/go/network/adapter/home.htm
62
63 29
64Command Line Parameters 30Command Line Parameters
65======================= 31=======================
66 32
67If the driver is built as a module, the following optional parameters
68are used by entering them on the command line with the modprobe command
69using this syntax:
70
71 modprobe e1000 [<option>=<VAL1>,<VAL2>,...]
72
73For example, with two PRO/1000 PCI adapters, entering:
74
75 modprobe e1000 TxDescriptors=80,128
76
77loads the e1000 driver with 80 TX descriptors for the first adapter and
78128 TX descriptors for the second adapter.
79
80The default value for each parameter is generally the recommended setting, 33The default value for each parameter is generally the recommended setting,
81unless otherwise noted. 34unless otherwise noted.
82 35
@@ -89,10 +42,6 @@ NOTES: For more information about the AutoNeg, Duplex, and Speed
89 parameters, see the application note at: 42 parameters, see the application note at:
90 http://www.intel.com/design/network/applnots/ap450.htm 43 http://www.intel.com/design/network/applnots/ap450.htm
91 44
92 A descriptor describes a data buffer and attributes related to
93 the data buffer. This information is accessed by the hardware.
94
95
96AutoNeg 45AutoNeg
97------- 46-------
98(Supported only on adapters with copper connections) 47(Supported only on adapters with copper connections)
@@ -106,7 +55,6 @@ Duplex parameters must not be specified.
106NOTE: Refer to the Speed and Duplex section of this readme for more 55NOTE: Refer to the Speed and Duplex section of this readme for more
107 information on the AutoNeg parameter. 56 information on the AutoNeg parameter.
108 57
109
110Duplex 58Duplex
111------ 59------
112(Supported only on adapters with copper connections) 60(Supported only on adapters with copper connections)
@@ -119,7 +67,6 @@ set to auto-negotiate, the board auto-detects the correct duplex. If the
119link partner is forced (either full or half), Duplex defaults to half- 67link partner is forced (either full or half), Duplex defaults to half-
120duplex. 68duplex.
121 69
122
123FlowControl 70FlowControl
124----------- 71-----------
125Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx) 72Valid Range: 0-3 (0=none, 1=Rx only, 2=Tx only, 3=Rx&Tx)
@@ -128,16 +75,16 @@ Default Value: Reads flow control settings from the EEPROM
128This parameter controls the automatic generation(Tx) and response(Rx) 75This parameter controls the automatic generation(Tx) and response(Rx)
129to Ethernet PAUSE frames. 76to Ethernet PAUSE frames.
130 77
131
132InterruptThrottleRate 78InterruptThrottleRate
133--------------------- 79---------------------
134(not supported on Intel(R) 82542, 82543 or 82544-based adapters) 80(not supported on Intel(R) 82542, 82543 or 82544-based adapters)
135Valid Range: 0,1,3,100-100000 (0=off, 1=dynamic, 3=dynamic conservative) 81Valid Range: 0,1,3,4,100-100000 (0=off, 1=dynamic, 3=dynamic conservative,
82 4=simplified balancing)
136Default Value: 3 83Default Value: 3
137 84
138The driver can limit the amount of interrupts per second that the adapter 85The driver can limit the amount of interrupts per second that the adapter
139will generate for incoming packets. It does this by writing a value to the 86will generate for incoming packets. It does this by writing a value to the
140adapter that is based on the maximum amount of interrupts that the adapter 87adapter that is based on the maximum amount of interrupts that the adapter
141will generate per second. 88will generate per second.
142 89
143Setting InterruptThrottleRate to a value greater or equal to 100 90Setting InterruptThrottleRate to a value greater or equal to 100
@@ -146,37 +93,43 @@ per second, even if more packets have come in. This reduces interrupt
146load on the system and can lower CPU utilization under heavy load, 93load on the system and can lower CPU utilization under heavy load,
147but will increase latency as packets are not processed as quickly. 94but will increase latency as packets are not processed as quickly.
148 95
149The default behaviour of the driver previously assumed a static 96The default behaviour of the driver previously assumed a static
150InterruptThrottleRate value of 8000, providing a good fallback value for 97InterruptThrottleRate value of 8000, providing a good fallback value for
151all traffic types,but lacking in small packet performance and latency. 98all traffic types,but lacking in small packet performance and latency.
152The hardware can handle many more small packets per second however, and 99The hardware can handle many more small packets per second however, and
153for this reason an adaptive interrupt moderation algorithm was implemented. 100for this reason an adaptive interrupt moderation algorithm was implemented.
154 101
155Since 7.3.x, the driver has two adaptive modes (setting 1 or 3) in which 102Since 7.3.x, the driver has two adaptive modes (setting 1 or 3) in which
156it dynamically adjusts the InterruptThrottleRate value based on the traffic 103it dynamically adjusts the InterruptThrottleRate value based on the traffic
157that it receives. After determining the type of incoming traffic in the last 104that it receives. After determining the type of incoming traffic in the last
158timeframe, it will adjust the InterruptThrottleRate to an appropriate value 105timeframe, it will adjust the InterruptThrottleRate to an appropriate value
159for that traffic. 106for that traffic.
160 107
161The algorithm classifies the incoming traffic every interval into 108The algorithm classifies the incoming traffic every interval into
162classes. Once the class is determined, the InterruptThrottleRate value is 109classes. Once the class is determined, the InterruptThrottleRate value is
163adjusted to suit that traffic type the best. There are three classes defined: 110adjusted to suit that traffic type the best. There are three classes defined:
164"Bulk traffic", for large amounts of packets of normal size; "Low latency", 111"Bulk traffic", for large amounts of packets of normal size; "Low latency",
165for small amounts of traffic and/or a significant percentage of small 112for small amounts of traffic and/or a significant percentage of small
166packets; and "Lowest latency", for almost completely small packets or 113packets; and "Lowest latency", for almost completely small packets or
167minimal traffic. 114minimal traffic.
168 115
169In dynamic conservative mode, the InterruptThrottleRate value is set to 4000 116In dynamic conservative mode, the InterruptThrottleRate value is set to 4000
170for traffic that falls in class "Bulk traffic". If traffic falls in the "Low 117for traffic that falls in class "Bulk traffic". If traffic falls in the "Low
171latency" or "Lowest latency" class, the InterruptThrottleRate is increased 118latency" or "Lowest latency" class, the InterruptThrottleRate is increased
172stepwise to 20000. This default mode is suitable for most applications. 119stepwise to 20000. This default mode is suitable for most applications.
173 120
174For situations where low latency is vital such as cluster or 121For situations where low latency is vital such as cluster or
175grid computing, the algorithm can reduce latency even more when 122grid computing, the algorithm can reduce latency even more when
176InterruptThrottleRate is set to mode 1. In this mode, which operates 123InterruptThrottleRate is set to mode 1. In this mode, which operates
177the same as mode 3, the InterruptThrottleRate will be increased stepwise to 124the same as mode 3, the InterruptThrottleRate will be increased stepwise to
17870000 for traffic in class "Lowest latency". 12570000 for traffic in class "Lowest latency".
179 126
127In simplified mode the interrupt rate is based on the ratio of Tx and
128Rx traffic. If the bytes per second rate is approximately equal, the
129interrupt rate will drop as low as 2000 interrupts per second. If the
130traffic is mostly transmit or mostly receive, the interrupt rate could
131be as high as 8000.
132
180Setting InterruptThrottleRate to 0 turns off any interrupt moderation 133Setting InterruptThrottleRate to 0 turns off any interrupt moderation
181and may improve small packet latency, but is generally not suitable 134and may improve small packet latency, but is generally not suitable
182for bulk throughput traffic. 135for bulk throughput traffic.
@@ -212,8 +165,6 @@ NOTE: When e1000 is loaded with default settings and multiple adapters
212 be platform-specific. If CPU utilization is not a concern, use 165 be platform-specific. If CPU utilization is not a concern, use
213 RX_POLLING (NAPI) and default driver settings. 166 RX_POLLING (NAPI) and default driver settings.
214 167
215
216
217RxDescriptors 168RxDescriptors
218------------- 169-------------
219Valid Range: 80-256 for 82542 and 82543-based adapters 170Valid Range: 80-256 for 82542 and 82543-based adapters
@@ -225,15 +176,14 @@ by the driver. Increasing this value allows the driver to buffer more
225incoming packets, at the expense of increased system memory utilization. 176incoming packets, at the expense of increased system memory utilization.
226 177
227Each descriptor is 16 bytes. A receive buffer is also allocated for each 178Each descriptor is 16 bytes. A receive buffer is also allocated for each
228descriptor and can be either 2048, 4096, 8192, or 16384 bytes, depending 179descriptor and can be either 2048, 4096, 8192, or 16384 bytes, depending
229on the MTU setting. The maximum MTU size is 16110. 180on the MTU setting. The maximum MTU size is 16110.
230 181
231NOTE: MTU designates the frame size. It only needs to be set for Jumbo 182NOTE: MTU designates the frame size. It only needs to be set for Jumbo
232 Frames. Depending on the available system resources, the request 183 Frames. Depending on the available system resources, the request
233 for a higher number of receive descriptors may be denied. In this 184 for a higher number of receive descriptors may be denied. In this
234 case, use a lower number. 185 case, use a lower number.
235 186
236
237RxIntDelay 187RxIntDelay
238---------- 188----------
239Valid Range: 0-65535 (0=off) 189Valid Range: 0-65535 (0=off)
@@ -254,7 +204,6 @@ CAUTION: When setting RxIntDelay to a value other than 0, adapters may
254 restoring the network connection. To eliminate the potential 204 restoring the network connection. To eliminate the potential
255 for the hang ensure that RxIntDelay is set to 0. 205 for the hang ensure that RxIntDelay is set to 0.
256 206
257
258RxAbsIntDelay 207RxAbsIntDelay
259------------- 208-------------
260(This parameter is supported only on 82540, 82545 and later adapters.) 209(This parameter is supported only on 82540, 82545 and later adapters.)
@@ -268,7 +217,6 @@ packet is received within the set amount of time. Proper tuning,
268along with RxIntDelay, may improve traffic throughput in specific network 217along with RxIntDelay, may improve traffic throughput in specific network
269conditions. 218conditions.
270 219
271
272Speed 220Speed
273----- 221-----
274(This parameter is supported only on adapters with copper connections.) 222(This parameter is supported only on adapters with copper connections.)
@@ -280,7 +228,6 @@ Speed forces the line speed to the specified value in megabits per second
280partner is set to auto-negotiate, the board will auto-detect the correct 228partner is set to auto-negotiate, the board will auto-detect the correct
281speed. Duplex should also be set when Speed is set to either 10 or 100. 229speed. Duplex should also be set when Speed is set to either 10 or 100.
282 230
283
284TxDescriptors 231TxDescriptors
285------------- 232-------------
286Valid Range: 80-256 for 82542 and 82543-based adapters 233Valid Range: 80-256 for 82542 and 82543-based adapters
@@ -295,6 +242,36 @@ NOTE: Depending on the available system resources, the request for a
295 higher number of transmit descriptors may be denied. In this case, 242 higher number of transmit descriptors may be denied. In this case,
296 use a lower number. 243 use a lower number.
297 244
245TxDescriptorStep
246----------------
247Valid Range: 1 (use every Tx Descriptor)
248 4 (use every 4th Tx Descriptor)
249
250Default Value: 1 (use every Tx Descriptor)
251
252On certain non-Intel architectures, it has been observed that intense TX
253traffic bursts of short packets may result in an improper descriptor
254writeback. If this occurs, the driver will report a "TX Timeout" and reset
255the adapter, after which the transmit flow will restart, though data may
256have stalled for as much as 10 seconds before it resumes.
257
258The improper writeback does not occur on the first descriptor in a system
259memory cache-line, which is typically 32 bytes, or 4 descriptors long.
260
261Setting TxDescriptorStep to a value of 4 will ensure that all TX descriptors
262are aligned to the start of a system memory cache line, and so this problem
263will not occur.
264
265NOTES: Setting TxDescriptorStep to 4 effectively reduces the number of
266 TxDescriptors available for transmits to 1/4 of the normal allocation.
267 This has a possible negative performance impact, which may be
268 compensated for by allocating more descriptors using the TxDescriptors
269 module parameter.
270
271 There are other conditions which may result in "TX Timeout", which will
272 not be resolved by the use of the TxDescriptorStep parameter. As the
273 issue addressed by this parameter has never been observed on Intel
274 Architecture platforms, it should not be used on Intel platforms.
298 275
299TxIntDelay 276TxIntDelay
300---------- 277----------
@@ -307,7 +284,6 @@ efficiency if properly tuned for specific network traffic. If the
307system is reporting dropped transmits, this value may be set too high 284system is reporting dropped transmits, this value may be set too high
308causing the driver to run out of available transmit descriptors. 285causing the driver to run out of available transmit descriptors.
309 286
310
311TxAbsIntDelay 287TxAbsIntDelay
312------------- 288-------------
313(This parameter is supported only on 82540, 82545 and later adapters.) 289(This parameter is supported only on 82540, 82545 and later adapters.)
@@ -330,6 +306,35 @@ Default Value: 1
330A value of '1' indicates that the driver should enable IP checksum 306A value of '1' indicates that the driver should enable IP checksum
331offload for received packets (both UDP and TCP) to the adapter hardware. 307offload for received packets (both UDP and TCP) to the adapter hardware.
332 308
309Copybreak
310---------
311Valid Range: 0-xxxxxxx (0=off)
312Default Value: 256
313Usage: insmod e1000.ko copybreak=128
314
315Driver copies all packets below or equaling this size to a fresh Rx
316buffer before handing it up the stack.
317
318This parameter is different than other parameters, in that it is a
319single (not 1,1,1 etc.) parameter applied to all driver instances and
320it is also available during runtime at
321/sys/module/e1000/parameters/copybreak
322
323SmartPowerDownEnable
324--------------------
325Valid Range: 0-1
326Default Value: 0 (disabled)
327
328Allows PHY to turn off in lower power states. The user can turn off
329this parameter in supported chipsets.
330
331KumeranLockLoss
332---------------
333Valid Range: 0-1
334Default Value: 1 (enabled)
335
336This workaround skips resetting the PHY at shutdown for the initial
337silicon releases of ICH8 systems.
333 338
334Speed and Duplex Configuration 339Speed and Duplex Configuration
335============================== 340==============================
@@ -385,40 +390,9 @@ If the link partner is forced to a specific speed and duplex, then this
385parameter should not be used. Instead, use the Speed and Duplex parameters 390parameter should not be used. Instead, use the Speed and Duplex parameters
386previously mentioned to force the adapter to the same speed and duplex. 391previously mentioned to force the adapter to the same speed and duplex.
387 392
388
389Additional Configurations 393Additional Configurations
390========================= 394=========================
391 395
392 Configuring the Driver on Different Distributions
393 -------------------------------------------------
394 Configuring a network driver to load properly when the system is started
395 is distribution dependent. Typically, the configuration process involves
396 adding an alias line to /etc/modules.conf or /etc/modprobe.conf as well
397 as editing other system startup scripts and/or configuration files. Many
398 popular Linux distributions ship with tools to make these changes for you.
399 To learn the proper way to configure a network device for your system,
400 refer to your distribution documentation. If during this process you are
401 asked for the driver or module name, the name for the Linux Base Driver
402 for the Intel(R) PRO/1000 Family of Adapters is e1000.
403
404 As an example, if you install the e1000 driver for two PRO/1000 adapters
405 (eth0 and eth1) and set the speed and duplex to 10full and 100half, add
406 the following to modules.conf or or modprobe.conf:
407
408 alias eth0 e1000
409 alias eth1 e1000
410 options e1000 Speed=10,100 Duplex=2,1
411
412 Viewing Link Messages
413 ---------------------
414 Link messages will not be displayed to the console if the distribution is
415 restricting system messages. In order to see network driver link messages
416 on your console, set dmesg to eight by entering the following:
417
418 dmesg -n 8
419
420 NOTE: This setting is not saved across reboots.
421
422 Jumbo Frames 396 Jumbo Frames
423 ------------ 397 ------------
424 Jumbo Frames support is enabled by changing the MTU to a value larger than 398 Jumbo Frames support is enabled by changing the MTU to a value larger than
@@ -437,9 +411,11 @@ Additional Configurations
437 setting in a different location. 411 setting in a different location.
438 412
439 Notes: 413 Notes:
440 414 Degradation in throughput performance may be observed in some Jumbo frames
441 - To enable Jumbo Frames, increase the MTU size on the interface beyond 415 environments. If this is observed, increasing the application's socket buffer
442 1500. 416 size and/or increasing the /proc/sys/net/ipv4/tcp_*mem entry values may help.
417 See the specific application manual and /usr/src/linux*/Documentation/
418 networking/ip-sysctl.txt for more details.
443 419
444 - The maximum MTU setting for Jumbo Frames is 16110. This value coincides 420 - The maximum MTU setting for Jumbo Frames is 16110. This value coincides
445 with the maximum Jumbo Frames size of 16128. 421 with the maximum Jumbo Frames size of 16128.
@@ -447,40 +423,11 @@ Additional Configurations
447 - Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or 423 - Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or
448 loss of link. 424 loss of link.
449 425
450 - Some Intel gigabit adapters that support Jumbo Frames have a frame size
451 limit of 9238 bytes, with a corresponding MTU size limit of 9216 bytes.
452 The adapters with this limitation are based on the Intel(R) 82571EB,
453 82572EI, 82573L and 80003ES2LAN controller. These correspond to the
454 following product names:
455 Intel(R) PRO/1000 PT Server Adapter
456 Intel(R) PRO/1000 PT Desktop Adapter
457 Intel(R) PRO/1000 PT Network Connection
458 Intel(R) PRO/1000 PT Dual Port Server Adapter
459 Intel(R) PRO/1000 PT Dual Port Network Connection
460 Intel(R) PRO/1000 PF Server Adapter
461 Intel(R) PRO/1000 PF Network Connection
462 Intel(R) PRO/1000 PF Dual Port Server Adapter
463 Intel(R) PRO/1000 PB Server Connection
464 Intel(R) PRO/1000 PL Network Connection
465 Intel(R) PRO/1000 EB Network Connection with I/O Acceleration
466 Intel(R) PRO/1000 EB Backplane Connection with I/O Acceleration
467 Intel(R) PRO/1000 PT Quad Port Server Adapter
468
469 - Adapters based on the Intel(R) 82542 and 82573V/E controller do not 426 - Adapters based on the Intel(R) 82542 and 82573V/E controller do not
470 support Jumbo Frames. These correspond to the following product names: 427 support Jumbo Frames. These correspond to the following product names:
471 Intel(R) PRO/1000 Gigabit Server Adapter 428 Intel(R) PRO/1000 Gigabit Server Adapter
472 Intel(R) PRO/1000 PM Network Connection 429 Intel(R) PRO/1000 PM Network Connection
473 430
474 - The following adapters do not support Jumbo Frames:
475 Intel(R) 82562V 10/100 Network Connection
476 Intel(R) 82566DM Gigabit Network Connection
477 Intel(R) 82566DC Gigabit Network Connection
478 Intel(R) 82566MM Gigabit Network Connection
479 Intel(R) 82566MC Gigabit Network Connection
480 Intel(R) 82562GT 10/100 Network Connection
481 Intel(R) 82562G 10/100 Network Connection
482
483
484 Ethtool 431 Ethtool
485 ------- 432 -------
486 The driver utilizes the ethtool interface for driver configuration and 433 The driver utilizes the ethtool interface for driver configuration and
@@ -490,142 +437,14 @@ Additional Configurations
490 The latest release of ethtool can be found from 437 The latest release of ethtool can be found from
491 http://sourceforge.net/projects/gkernel. 438 http://sourceforge.net/projects/gkernel.
492 439
493 NOTE: Ethtool 1.6 only supports a limited set of ethtool options. Support
494 for a more complete ethtool feature set can be enabled by upgrading
495 ethtool to ethtool-1.8.1.
496
497 Enabling Wake on LAN* (WoL) 440 Enabling Wake on LAN* (WoL)
498 --------------------------- 441 ---------------------------
499 WoL is configured through the Ethtool* utility. Ethtool is included with 442 WoL is configured through the Ethtool* utility.
500 all versions of Red Hat after Red Hat 7.2. For other Linux distributions,
501 download and install Ethtool from the following website:
502 http://sourceforge.net/projects/gkernel.
503
504 For instructions on enabling WoL with Ethtool, refer to the website listed
505 above.
506 443
507 WoL will be enabled on the system during the next shut down or reboot. 444 WoL will be enabled on the system during the next shut down or reboot.
508 For this driver version, in order to enable WoL, the e1000 driver must be 445 For this driver version, in order to enable WoL, the e1000 driver must be
509 loaded when shutting down or rebooting the system. 446 loaded when shutting down or rebooting the system.
510 447
511 Wake On LAN is only supported on port A for the following devices:
512 Intel(R) PRO/1000 PT Dual Port Network Connection
513 Intel(R) PRO/1000 PT Dual Port Server Connection
514 Intel(R) PRO/1000 PT Dual Port Server Adapter
515 Intel(R) PRO/1000 PF Dual Port Server Adapter
516 Intel(R) PRO/1000 PT Quad Port Server Adapter
517
518 NAPI
519 ----
520 NAPI (Rx polling mode) is enabled in the e1000 driver.
521
522 See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI.
523
524
525Known Issues
526============
527
528Dropped Receive Packets on Half-duplex 10/100 Networks
529------------------------------------------------------
530If you have an Intel PCI Express adapter running at 10mbps or 100mbps, half-
531duplex, you may observe occasional dropped receive packets. There are no
532workarounds for this problem in this network configuration. The network must
533be updated to operate in full-duplex, and/or 1000mbps only.
534
535Jumbo Frames System Requirement
536-------------------------------
537Memory allocation failures have been observed on Linux systems with 64 MB
538of RAM or less that are running Jumbo Frames. If you are using Jumbo
539Frames, your system may require more than the advertised minimum
540requirement of 64 MB of system memory.
541
542Performance Degradation with Jumbo Frames
543-----------------------------------------
544Degradation in throughput performance may be observed in some Jumbo frames
545environments. If this is observed, increasing the application's socket
546buffer size and/or increasing the /proc/sys/net/ipv4/tcp_*mem entry values
547may help. See the specific application manual and
548/usr/src/linux*/Documentation/
549networking/ip-sysctl.txt for more details.
550
551Jumbo Frames on Foundry BigIron 8000 switch
552-------------------------------------------
553There is a known issue using Jumbo frames when connected to a Foundry
554BigIron 8000 switch. This is a 3rd party limitation. If you experience
555loss of packets, lower the MTU size.
556
557Allocating Rx Buffers when Using Jumbo Frames
558---------------------------------------------
559Allocating Rx buffers when using Jumbo Frames on 2.6.x kernels may fail if
560the available memory is heavily fragmented. This issue may be seen with PCI-X
561adapters or with packet split disabled. This can be reduced or eliminated
562by changing the amount of available memory for receive buffer allocation, by
563increasing /proc/sys/vm/min_free_kbytes.
564
565Multiple Interfaces on Same Ethernet Broadcast Network
566------------------------------------------------------
567Due to the default ARP behavior on Linux, it is not possible to have
568one system on two IP networks in the same Ethernet broadcast domain
569(non-partitioned switch) behave as expected. All Ethernet interfaces
570will respond to IP traffic for any IP address assigned to the system.
571This results in unbalanced receive traffic.
572
573If you have multiple interfaces in a server, either turn on ARP
574filtering by entering:
575
576 echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
577(this only works if your kernel's version is higher than 2.4.5),
578
579NOTE: This setting is not saved across reboots. The configuration
580change can be made permanent by adding the line:
581 net.ipv4.conf.all.arp_filter = 1
582to the file /etc/sysctl.conf
583
584 or,
585
586install the interfaces in separate broadcast domains (either in
587different switches or in a switch partitioned to VLANs).
588
58982541/82547 can't link or are slow to link with some link partners
590-----------------------------------------------------------------
591There is a known compatibility issue with 82541/82547 and some
592low-end switches where the link will not be established, or will
593be slow to establish. In particular, these switches are known to
594be incompatible with 82541/82547:
595
596 Planex FXG-08TE
597 I-O Data ETG-SH8
598
599To workaround this issue, the driver can be compiled with an override
600of the PHY's master/slave setting. Forcing master or forcing slave
601mode will improve time-to-link.
602
603 # make CFLAGS_EXTRA=-DE1000_MASTER_SLAVE=<n>
604
605Where <n> is:
606
607 0 = Hardware default
608 1 = Master mode
609 2 = Slave mode
610 3 = Auto master/slave
611
612Disable rx flow control with ethtool
613------------------------------------
614In order to disable receive flow control using ethtool, you must turn
615off auto-negotiation on the same command line.
616
617For example:
618
619 ethtool -A eth? autoneg off rx off
620
621Unplugging network cable while ethtool -p is running
622----------------------------------------------------
623In kernel versions 2.5.50 and later (including 2.6 kernel), unplugging
624the network cable while ethtool -p is running will cause the system to
625become unresponsive to keyboard commands, except for control-alt-delete.
626Restarting the system appears to be the only remedy.
627
628
629Support 448Support
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631 450