EM(4)

NAME
em - Intel PRO/1000 10/100/1Gb Ethernet device

SYNOPSIS
em* at pci?

DESCRIPTION
The em driver provides support for PCI, PCI-X and PCI Express Gigabit Ethernet adapters based on the Intel 82540EM, 82540EP, 82541EI, 82541ER, 82541GI, 82541PI, 82542, 82543GC, 82544EI, 82544GC, 82545EM, 82545GM, 82546EB, 82546GB, 82547EI, 82547GI, 82562V, 82563EB, 82564EB, 82566DC, 82566DM, 82571EB, 82571GB, 82572EI, 82572GI, 82573E, 82573L, 82573V, 82574L, 82575EB, 82575GB, 82576EB, 82577LC, 82577LM, 82578DC, 82578DM, 82579LM, 82579V, 82580DB, 82580EB, 82583V, I210, I211, I217, I218, I219, I350, I354 Ethernet controller chips and the embedded chips found on EP80579 platform, including the following:

Axiomtek NA-200 EP80579 based board
HP ProLiant NC110T PCI Express Gigabit NIC
HP ProLiant NC112T PCI Express Gigabit NIC
HP ProLiant NC310F PCI-X Gigabit NIC (SX Fiber)
HP ProLiant NC340T PCI-X Quad Port Gigabit NIC
HP ProLiant NC360T PCI Express Dual Port Gigabit NIC
HP ProLiant NC364T PCI Express Quad Port Gigabit NIC
HP ProLiant NC365T PCI Express Quad Port Gigabit NIC
HP ProLiant NC6132 Upgrade Module (SX Fiber)
HP ProLiant NC6133 Upgrade Module (LX Fiber)
HP ProLiant NC6134 PCI Gigabit NIC (SX Fiber)
HP ProLiant NC6136 PCI Gigabit NIC (SX Fiber)
HP ProLiant NC6170 PCI-X Gigabit NIC (SX Fiber)
HP ProLiant NC7131 PCI Gigabit NIC
HP ProLiant NC7132 Upgrade Module
HP ProLiant NC7170 PCI-X Dual Port Gigabit NIC
HP ProLiant NC7170LP PCI-X Dual Port Gigabit NIC
Intel PRO/1000 Gigabit Server Adapter (SX Fiber) (PWLA8490)
Intel PRO/1000F Gigabit Server Adapter (SX Fiber) (PWLA8490SX)
Intel PRO/1000T Server Adapter (PWLA8490T)
Intel PRO/1000XT Server Adapter (PWLA8490XT)
Intel PRO/1000XS Server Adapter (SX Fiber) (PWLA8490XF)
Intel PRO/1000T Desktop Adapter (PWLA8390T)
Intel PRO/1000XTL Low Profile PCI Server (PWLA8490XTL)
Intel PRO/1000MT Desktop Adapter (PWLA8390MT)
Intel PRO/1000MT Server Adapter (PWLA8490MT)
Intel PRO/1000MT Dual Port Server Adapter (PWLA8492MT)
Intel PRO/1000MF Server Adapter (SX Fiber) (PWLA8490MF)
Intel PRO/1000MF Dual Port Server Adapter (SX Fiber) (PWLA8492MF)
Intel PRO/1000MF Server Adapter (LX Fiber) (PWLA8490LX)
Intel PRO/1000MT Quad PCI-X Adapter (PWLA8494MT)
Intel PRO/1000GT Quad PCI-X Adapter (PWLA8494GT)
Intel PRO/1000PT Desktop Adapter
Intel PRO/1000PT Server Adapter
Intel PRO/1000PT Dual Port Server Adapter
Intel PRO/1000PT Quad Port Server Adapter
Intel PRO/1000PF Server Adapter (SX Fiber)
Intel PRO/1000PF Dual Port Server Adapter (SX Fiber)
Intel PRO/1000ET Dual Port Server Adapter
Intel PRO/1000ET Quad Port Server Adapter
Intel PRO/1000EF Quad Port Server Adapter (SX Fiber)
Intel I340-T4 PCI Express Quad Port Gigabit NIC
Intel I350-T2 PCI Express Dual Port Gigabit NIC
Intel I350-T4 PCI Express Quad Port Gigabit NIC
Soekris Engineering lan1841
Sun PCI-E Dual Gigabit Ethernet LP UTP Adapter
Sun PCI-E Dual Gigabit Ethernet LP MMF Adapter
Sun PCI-E Dual Gigabit Ethernet EM UTP Adapter
Sun PCI-E Dual Gigabit Ethernet EM MMF Adapter
Sun PCI-E Dual Gigabit Ethernet ExpressModule
Sun x4 PCI-E Quad Gigabit Ethernet LP UTP Adapter
Sun x4 PCI-E Quad Gigabit Ethernet ExpressModule
Sun x8 PCI-E Quad Gigabit Ethernet ExpressModule
Supermicro AOC-SG-i2 Dual Port Server Adapter
Supermicro AOC-PG-I2+ Dual Port Server Adapter

The em driver supports IPv4 receive IP/TCP/UDP checksum offload and transmit TCP/UDP checksum offload on all but 82542-based adapters, VLAN tag insertion and stripping, and jumbo frames on all but 82562V, 82566DC/82566DM and 82573E/82573L/82573V-based adapters. The 82562V Ethernet controller chip only supports 10/100 media types.

The em driver supports the following media types:

autoselect
    Enables auto-negotiation for speed and duplex.

10baseT mediaopt full-duplex
    Sets 10Mbps operation.

100baseTX mediaopt full-duplex
    Sets 100Mbps operation.

1000baseLX
    Sets 1000Mbps operation. Only full-duplex mode is supported at this speed.

1000baseSX
    Sets 1000Mbps operation. Only full-duplex mode is supported at this speed.

1000baseT
    Sets 1000Mbps operation. Only full-duplex mode is supported at this speed.

For more information on configuring this device, see ifconfig(8).

SEE ALSO
arp(4), gcu(4), ifmedia(4), intro(4), netintro(4), pci(4), hostname.if(5), ifconfig(8)

HISTORY
The em device driver first appeared in OpenBSD 3.2.

AUTHORS
The em driver was written by Intel Corporation.

BUGS
There are known performance issues with this driver when running UDP traffic with jumbo frames.

There is a known compatibility issue where time to link is slow or link is not established between 82541/82547 controllers and some switches. Known switches include:

I-O Data ETG-SH8
Planex FXG-08TE