.\" Copyright (c) 1986, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)ex.4	8.1 (Berkeley) 06/05/93
.\"
.Dd 
.Dt EX 4 vax
.Os BSD 4.2
.Sh NAME
.Nm ex
.Nd Excelan 10 Mb/s Ethernet interface
.Sh SYNOPSIS
.Cd "device ex0 at uba0 csr 164000 vector excdint"
.Sh DESCRIPTION
The
.Nm ex
interface provides access to a 10 Mb/s Ethernet network through
an Excelan controller used as a link-layer interface.
.Pp
Each of the host's network addresses
is specified at boot time with an
.Dv SIOCSIFADDR
.Xr ioctl 2 .
The
.Nm ex
interface employs the address resolution protocol described in
.Xr arp 4
to dynamically map between Internet and Ethernet addresses on the local
network.
.Pp
The interface normally tries to use a
.Dq trailer
encapsulation
to minimize copying data on input and output.
The use of trailers is negotiated with
.Tn ARP .
This negotiation may be disabled, on a per-interface basis,
by setting the
.Dv IFF_NOTRAILERS
flag with an
.Dv SIOCSIFFLAGS
.Xr ioctl .
.Sh DIAGNOSTICS
.Bl -diag
.It "ex%d: HW %c.%c, NX %c.%c, hardware address %s."
This provides firmware revisions levels, and is expected during
autoconfiguration.
.Pp
.It ex%d: can't initialize.
There was a failure in allocating unibus resources for the device.
.Pp
.It "ex%d: configuration failed; cc = %x."
The hardware indicated an error when trying to initalize itself.
The error code returned is described at length in the device
Reference Manual.
.Pp
.It ex%d: receive error %b.
The hardware indicated an error
in reading a packet from the cable.
Specific Error bits are provided
.Pp
.It ex%d: transmit error %b.
The hardware indicated an error
in transmitting a packet to the cable or an illegally sized packet.
Specific Error bits are provided
.Pp
.It ex%d: can't handle af%d.
The interface was handed
a message with addresses formatted in an unsuitable address
family; the packet was dropped.
.El
.Sh SEE ALSO
.Xr netintro 4 ,
.Xr inet 4 ,
.Xr arp 4
.Sh HISTORY
The
.Nm
driver appeared in
.Bx 4.3 .