EM(4) | Device Drivers Manual | 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

September 8, 2021 | Debian