1.. SPDX-License-Identifier: GPL-2.0+
2
3==========================================================
4Linux Base Driver for Intel(R) Ethernet Network Connection
5==========================================================
6
7Intel Gigabit Linux driver.
8Copyright(c) 1999-2018 Intel Corporation.
9
10Contents
11========
12
13- Identifying Your Adapter
14- Command Line Parameters
15- Additional Configurations
16- Support
17
18
19Identifying Your Adapter
20========================
21For information on how to identify your adapter, and for the latest Intel
22network drivers, refer to the Intel Support website:
23https://www.intel.com/support
24
25
26Command Line Parameters
27========================
28If the driver is built as a module, the following optional parameters are used
29by entering them on the command line with the modprobe command using this
30syntax::
31
32    modprobe igb [<option>=<VAL1>,<VAL2>,...]
33
34There needs to be a <VAL#> for each network port in the system supported by
35this driver. The values will be applied to each instance, in function order.
36For example::
37
38    modprobe igb max_vfs=2,4
39
40In this case, there are two network ports supported by igb in the system.
41
42NOTE: A descriptor describes a data buffer and attributes related to the data
43buffer. This information is accessed by the hardware.
44
45max_vfs
46-------
47:Valid Range: 0-7
48
49This parameter adds support for SR-IOV. It causes the driver to spawn up to
50max_vfs worth of virtual functions.  If the value is greater than 0 it will
51also force the VMDq parameter to be 1 or more.
52
53The parameters for the driver are referenced by position. Thus, if you have a
54dual port adapter, or more than one adapter in your system, and want N virtual
55functions per port, you must specify a number for each port with each parameter
56separated by a comma. For example::
57
58    modprobe igb max_vfs=4
59
60This will spawn 4 VFs on the first port.
61
62::
63
64    modprobe igb max_vfs=2,4
65
66This will spawn 2 VFs on the first port and 4 VFs on the second port.
67
68NOTE: Caution must be used in loading the driver with these parameters.
69Depending on your system configuration, number of slots, etc., it is impossible
70to predict in all cases where the positions would be on the command line.
71
72NOTE: Neither the device nor the driver control how VFs are mapped into config
73space. Bus layout will vary by operating system. On operating systems that
74support it, you can check sysfs to find the mapping.
75
76NOTE: When either SR-IOV mode or VMDq mode is enabled, hardware VLAN filtering
77and VLAN tag stripping/insertion will remain enabled. Please remove the old
78VLAN filter before the new VLAN filter is added. For example::
79
80    ip link set eth0 vf 0 vlan 100	// set vlan 100 for VF 0
81    ip link set eth0 vf 0 vlan 0	// Delete vlan 100
82    ip link set eth0 vf 0 vlan 200	// set a new vlan 200 for VF 0
83
84Debug
85-----
86:Valid Range: 0-16 (0=none,...,16=all)
87:Default Value: 0
88
89This parameter adjusts the level debug messages displayed in the system logs.
90
91
92Additional Features and Configurations
93======================================
94
95Jumbo Frames
96------------
97Jumbo Frames support is enabled by changing the Maximum Transmission Unit (MTU)
98to a value larger than the default value of 1500.
99
100Use the ifconfig command to increase the MTU size. For example, enter the
101following where <x> is the interface number::
102
103    ifconfig eth<x> mtu 9000 up
104
105Alternatively, you can use the ip command as follows::
106
107    ip link set mtu 9000 dev eth<x>
108    ip link set up dev eth<x>
109
110This setting is not saved across reboots. The setting change can be made
111permanent by adding 'MTU=9000' to the file:
112
113- For RHEL: /etc/sysconfig/network-scripts/ifcfg-eth<x>
114- For SLES: /etc/sysconfig/network/<config_file>
115
116NOTE: The maximum MTU setting for Jumbo Frames is 9216. This value coincides
117with the maximum Jumbo Frames size of 9234 bytes.
118
119NOTE: Using Jumbo frames at 10 or 100 Mbps is not supported and may result in
120poor performance or loss of link.
121
122
123ethtool
124-------
125The driver utilizes the ethtool interface for driver configuration and
126diagnostics, as well as displaying statistical information. The latest ethtool
127version is required for this functionality. Download it at:
128
129https://www.kernel.org/pub/software/network/ethtool/
130
131
132Enabling Wake on LAN (WoL)
133--------------------------
134WoL is configured through the ethtool utility.
135
136WoL will be enabled on the system during the next shut down or reboot. For
137this driver version, in order to enable WoL, the igb driver must be loaded
138prior to shutting down or suspending the system.
139
140NOTE: Wake on LAN is only supported on port A of multi-port devices.  Also
141Wake On LAN is not supported for the following device:
142- Intel(R) Gigabit VT Quad Port Server Adapter
143
144
145Multiqueue
146----------
147In this mode, a separate MSI-X vector is allocated for each queue and one for
148"other" interrupts such as link status change and errors. All interrupts are
149throttled via interrupt moderation. Interrupt moderation must be used to avoid
150interrupt storms while the driver is processing one interrupt. The moderation
151value should be at least as large as the expected time for the driver to
152process an interrupt. Multiqueue is off by default.
153
154REQUIREMENTS: MSI-X support is required for Multiqueue. If MSI-X is not found,
155the system will fallback to MSI or to Legacy interrupts. This driver supports
156receive multiqueue on all kernels that support MSI-X.
157
158NOTE: On some kernels a reboot is required to switch between single queue mode
159and multiqueue mode or vice-versa.
160
161
162MAC and VLAN anti-spoofing feature
163----------------------------------
164When a malicious driver attempts to send a spoofed packet, it is dropped by the
165hardware and not transmitted.
166
167An interrupt is sent to the PF driver notifying it of the spoof attempt. When a
168spoofed packet is detected, the PF driver will send the following message to
169the system log (displayed by the "dmesg" command):
170Spoof event(s) detected on VF(n), where n = the VF that attempted to do the
171spoofing
172
173
174Setting MAC Address, VLAN and Rate Limit Using IProute2 Tool
175------------------------------------------------------------
176You can set a MAC address of a Virtual Function (VF), a default VLAN and the
177rate limit using the IProute2 tool. Download the latest version of the
178IProute2 tool from Sourceforge if your version does not have all the features
179you require.
180
181Credit Based Shaper (Qav Mode)
182------------------------------
183When enabling the CBS qdisc in the hardware offload mode, traffic shaping using
184the CBS (described in the IEEE 802.1Q-2018 Section 8.6.8.2 and discussed in the
185Annex L) algorithm will run in the i210 controller, so it's more accurate and
186uses less CPU.
187
188When using offloaded CBS, and the traffic rate obeys the configured rate
189(doesn't go above it), CBS should have little to no effect in the latency.
190
191The offloaded version of the algorithm has some limits, caused by how the idle
192slope is expressed in the adapter's registers. It can only represent idle slopes
193in 16.38431 kbps units, which means that if a idle slope of 2576kbps is
194requested, the controller will be configured to use a idle slope of ~2589 kbps,
195because the driver rounds the value up. For more details, see the comments on
196:c:func:`igb_config_tx_modes()`.
197
198NOTE: This feature is exclusive to i210 models.
199
200
201Support
202=======
203For general information, go to the Intel support website at:
204https://www.intel.com/support/
205
206If an issue is identified with the released source code on a supported kernel
207with a supported adapter, email the specific information related to the issue
208to intel-wired-lan@lists.osuosl.org.
209