LNC(4)

NAME
lnc - AMD Am7900 LANCE and Am79C9xx PCnet Ethernet interface driver

SYNOPSIS
device lnc

DESCRIPTION
The lnc driver provides support for the AMD family of Lance/PCnet Ethernet NICs including the Am7990 and Am79C960.

The lnc driver also supports PCnet adapters based on the AMD 79C9xx family of chips, which are single-chip implementations of a LANCE chip and a DMA engine. This includes a superset of the PCI bus Ethernet chip sets supported by the pcn(4) driver. The lnc driver treats all of these PCI bus Ethernet chip sets 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 chip sets. Thus the pcn(4) driver should be preferred for the latter.

The lnc 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
The PCI bus Ethernet chip sets supported by the lnc driver are:

•   AMD Am53C974/Am79C970/Am79C974 PCnet-PCI
•   AMD Am79C970A PCnet-PCI II
•   AMD Am79C971 PCnet-FAST
•   AMD Am79C972 PCnet-FAST+
•   AMD Am79C973/Am79C975 PCnet-FAST III
•   AMD Am79C976 PCnet-PRO
•   AMD Am79C978 PCnet-Home

The lnc driver supports the following media types with these chip sets:

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 unlike the pcn(4) driver, the lnc driver does not support selecting 100Mbps (Fast Ethernet) media types.

For further information on configuring media types and options, see ifconfig(8).

DIAGNOSTICS

lnc%d: overflow More packets came in from the Ethernet than there was space in the LANCE receive buffers. Packets were missed.

lnc%d: receive buffer error The LANCE ran out of buffer space, packet dropped.

lnc%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.

lnc%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).

lnc%d: dropping chained buffer A packet did not fit into a single receive buffer and was dropped. Since the lnc 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.

lnc%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.

lnc%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.

lnc%d: controller failed to initialize Driver failed to start the LANCE. This is potentially a hardware failure.

lnc%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.

lnc%d: receiver disabled The receiver of the LANCE was turned off due to an error.

lnc%d: transmitter disabled The transmitter of the LANCE was turned off due to an error.

SEE ALSO
arp(4), ifmedia(4), intro(4), netintro(4), pcn(4), vlan(4), ifconfig(8)

HISTORY
The lnc driver first appeared in FreeBSD 2.2, it was replaced in DragonFly 1.5 with the le(4) driver from FreeBSD 6.1 which was in turn ported from NetBSD. The NetBSD driver was derived from the le(4) driver in 4.4BSD.

AUTHORS
-nosplit The lnc driver was ported to FreeBSD by Marius Strobl <marius@FreeBSD.org> and later ported to DragonFly by Bill Marquette <bill.marquette@gmail.com>.