EM(4) BSD Kernel Interfaces Manual EM(4)
em -- Intel(R) PRO/1000 Gigabit Ethernet adapter driver
The em driver provides support for PCI Gigabit Ethernet adapters based on
the Intel 82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546,
82546EB, 82546GB and 82547 Ethernet controller chips. The driver sup-
ports Transmit/Receive checksum offload and Jumbo Frames only on 82540,
82543, 82544 and 82546-based adapters. For further hardware information,
see the README included with the driver.
For questions related to hardware requirements, refer to the documenta-
tion supplied with your Intel PRO/1000 adapter. All hardware require-
ments listed apply to use with FreeBSD.
Support for Jumbo Frames is provided via the interface MTU setting.
Selecting an MTU larger than 1500 bytes with the ifconfig(8) utility con-
figures the adapter to receive and transmit Jumbo Frames. The maximum
MTU size for Jumbo Frames is 16114.
This driver version supports VLANs. For information on enabling VLANs,
see the README. The em driver supports the following media types:
autoselect Enables auto-negotiation for speed and duplex.
10baseT/UTP Sets 10Mbps operation. Use the mediaopt option to select
100baseTX Sets 100Mbps operation. Use the mediaopt option to select
1000baseSX Sets 1000Mbps operation. Only full-duplex mode is supported
at this speed.
1000baseTX Sets 1000Mbps operation. Only full-duplex mode is supported
at this speed.
The em driver supports the following media options:
full-duplex Forces full-duplex operation
half-duplex Forces half-duplex operation.
Only use mediaopt to set the driver to full-duplex. If mediaopt is not
specified, the driver defaults to half-duplex.
For more information on configuring this device, see ifconfig(8).
The em driver supports Gigabit Ethernet adapters based on the Intel
82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546, 82546EB,
82546GB and 82547 controller chips:
o Intel PRO/1000 CT Network Connection (82547)
o Intel PRO/1000 F Server Adapter (82543)
o Intel PRO/1000 Gigabit Server Adapter (82542)
o Intel PRO/1000 GT Desktop Adapter (82541PI)
o Intel PRO/1000 MF Dual Port Server Adapter (82546)
o Intel PRO/1000 MF Server Adapter (82545)
o Intel PRO/1000 MF Server Adapter (LX) (82545)
o Intel PRO/1000 MT Desktop Adapter (82540)
o Intel PRO/1000 MT Desktop Adapter (82541)
o Intel PRO/1000 MT Dual Port Server Adapter (82546)
o Intel PRO/1000 MT Quad Port Server Adapter (82546EB)
o Intel PRO/1000 MT Server Adapter (82545)
o Intel PRO/1000 T Desktop Adapter (82544)
o Intel PRO/1000 T Server Adapter (82543)
o Intel PRO/1000 XF Server Adapter (82544)
o Intel PRO/1000 XT Server Adapter (82544)
em%d: Unable to allocate bus resource: memory A fatal initialization
error has occurred.
em%d: Unable to allocate bus resource: interrupt A fatal initialization
error has occurred.
em%d: watchdog timeout -- resetting The device has stopped responding to
the network, or there is a problem with the network connection (cable).
For additional information regarding building and installation, see the
README included with the driver. For general information and support, go
to the Intel support website at: http://support.intel.com.
If an issue is identified with the released source code on the supported
kernel with a supported adapter, email the specific information related
to the issue to <freebsdnicATmailbox.com>.
arp(4), gx(4), netintro(4), ng_ether(4), polling(4), vlan(4), ifconfig(8)
The em device driver first appeared in FreeBSD 4.4.
The em driver was written by Intel Corporation
Hardware-assisted VLAN processing is disabled by default. You can enable
it on an em interface using ifconfig(8) unless you are going to run
bridge(4) on the interface. In any case, VLAN can operate safely without
the hardware acceleration.
BSD January 30, 2005 BSD