LE(4) FreeBSD Kernel Interfaces Manual LE(4)
NAME
le - AMD Am7900 LANCE and Am79C9xx ILACC/PCnet Ethernet interface driver
SYNOPSIS
To compile this driver into the kernel, place the following line in your
kernel configuration file:
device le
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
if_le_load="YES"
For ISA non-PnP adapters, the port address as well as the IRQ and the DRQ
numbers have to be specified in /boot/device.hints:
hint.le.0.at="isa"
hint.le.0.port="0x280"
hint.le.0.irq="10"
hint.le.0.drq="0"
DEPRECATION NOTICE
The le driver may not be present in FreeBSD 16.0 and later.
DESCRIPTION
The le driver provides support for Ethernet adapters based on the AMD
Am7990 and Am79C90 (CMOS, pin-compatible) Local Area Network Controller
for Ethernet (LANCE) chips.
The le driver also supports Ethernet adapters based on the AMD Am79C900
Integrated Local Area Communications Controller (ILACC) as well as the
Am79C9xx PCnet family of chips, which are single-chip implementations of
a LANCE chip and a DMA engine. The le driver treats all of these PCI bus
Ethernet chips as an AMD Am79C970 PCnet-PCI and does not support the
additional features like the MII bus and burst mode of AMD Am79C971
PCnet-FAST and greater chips.
Generally, the le driver aims at supporting as many different chips on as
many different platforms as possible, partially at the cost of the best
performance with some of these.
The le driver supports reception and transmission of extended frames for
vlan(4). Selective reception of multicast Ethernet frames is provided by
a 64-bit mask; multicast destination addresses are hashed to a bit entry
using the Ethernet CRC function.
HARDWARE
ISA
The le driver supports ISA bus Ethernet adapters which are based on the
following chips:
o AMD Am7990 and Am79C90 LANCE
o AMD Am79C960 PCnet-ISA
o AMD Am79C961 PCnet-ISA+
o AMD Am79C961A PCnet-ISA II
This includes support for the following Ethernet adapters:
ISA non-PnP:
o BICC Isolan
o Novell NE2100
ISA PnP:
o AMD AM1500T/AM2100
o AMD PCnet-32
o AMD PCnet-ISA
o Allied Telesyn AT-1500
o Boca LANCard Combo
o Cabletron E2100 Series DNI
o Cabletron E2200 Single Chip
o Melco Inc. LGY-IV
o Novell NE2100
o Racal InterLan EtherBlaster
The le driver does not support the selection of media types and options
via ifconfig(8) with ISA bus Ethernet adapters.
PCI
The PCI bus Ethernet chips supported by the le driver are:
o AMD Am53C974/Am79C970/Am79C974 PCnet-PCI
o AMD Am79C970A PCnet-PCI II
o AMD Am79C971 PCnet-FAST
o AMD Am79C972 PCnet-FAST+
o AMD Am79C973/Am79C975 PCnet-FAST III
o AMD Am79C976 PCnet-PRO
o AMD Am79C978 PCnet-Home
This includes support for the following Ethernet adapters:
o AcerLAN NIC P20
o Allied Telesyn AT-2450 and AT-2700 series
o VMware emulated AMD Am79C970A PCnet-PCI II interface
The le driver supports the selection of the following media types via
ifconfig(8) with PCI bus Ethernet adapters:
autoselect Enable autoselection of the media type.
10baseT/UTP Select UTP media.
10base5/AUI Select AUI/BNC media.
The following media option is supported with these media types:
full-duplex Select full duplex operation.
Note that the le driver does not support selecting 100Mbps (Fast
Ethernet) media types.
DIAGNOSTICS
le%d: overflow More packets came in from the Ethernet than there was
space in the LANCE receive buffers. Packets were missed.
le%d: receive buffer error The LANCE ran out of buffer space, packet
dropped.
le%d: lost carrier The Ethernet carrier disappeared during an attempt to
transmit. The LANCE will finish transmitting the current packet, but
will not automatically retry transmission if there is a collision.
le%d: excessive collisions, tdr %d The Ethernet was extremely busy or
jammed, outbound packets were dropped after 16 attempts to retransmit.
TDR is the abbreviation of "Time Domain Reflectometry". The optionally
reported TDR value is an internal counter of the interval between the
start of a transmission and the occurrence of a collision. This value
can be used to determine the distance from the Ethernet tap to the point
on the Ethernet cable that is shorted or open (unterminated).
le%d: dropping chained buffer A packet did not fit into a single receive
buffer and was dropped. Since the le driver allocates buffers large
enough to receive maximum sized Ethernet packets, this means some other
station on the LAN transmitted a packet larger than allowed by the
Ethernet standard.
le%d: transmit buffer error The LANCE ran out of buffer space before
finishing the transmission of a packet. If this error occurs, the driver
software has a bug.
le%d: underflow The LANCE ran out of buffer space before finishing the
transmission of a packet. If this error occurs, the driver software has
a bug.
le%d: controller failed to initialize Driver failed to start the LANCE.
This is potentially a hardware failure.
le%d: memory error RAM failed to respond within the timeout when the
LANCE wanted to read or write it. This is potentially a hardware
failure.
le%d: receiver disabled The receiver of the LANCE was turned off due to
an error.
le%d: transmitter disabled The transmitter of the LANCE was turned off
due to an error.
SEE ALSO
altq(4), arp(4), intro(4), netintro(4), vlan(4), ifconfig(8)
HISTORY
The le driver was ported from NetBSD and first appeared in FreeBSD 6.1.
The NetBSD version in turn was derived from the le driver which first
appeared in 4.4BSD.
AUTHORS
The le driver was ported by Marius Strobl <marius@FreeBSD.org>.
FreeBSD 15.1-STABLE-HBSD October 24, 2025 LE(4)